Why does ping by name fail when ping by ip succeeds

This is a very common problem and is faced by many people all the time. The real question here is

why does ping by name fail when ping by ip succeeds?

The answer to this question is very simple. It lies within your ISP or routing device. There is a specific service that converts host name to IPs and vice versa. For example if you were to type a specific web address in the browser and the browser searches for the relavent IP address and locates the website for you.

Now the thing is that most of the internet routers didnt not allow inter-network ping command. The situation became critical when they actually needed ping command but did fail to do so. The issue of ping command failing with name but succeeding with ip address is the blockage of ping command parameter to use the dns service to locate the relavent ip address. So on the real problem lies with your routing device or ISP server. They may have blocked your transmission.

Another important issue in this regard is the permission problem. If you are using an access permission bbased operating system most notably Vista. You have an access problem. The easiest solution in Windos vista is to do the following for succeeding with ping command using hostname

Click Start
type cmd
At the top of the menu right click on cmd.exe and click Run as Administrator
In the command prompt, type ping google.com


You will be able to ping it. Pretty simple. If you are running linux, check your administrative privalages to use services and try again.

Pathping command is also helpful in this regard.
Check this
Ping command demystified
Pathping command

Difference between lserver and server in nslookup

There are little chores you'll come to use nslookup for almost every day: finding the IP address or MX records for a given domain name, or querying a particular name server for data. We'll cover these first, before moving on to the more occasional stuff.

12.5.1. Looking Up Different Record Types

By default, nslookup looks up the address for a domain name, or the domain name for an address. You can look up any record type by changing the querytype, as we show in this example:

% nslookup


Default Server:  terminator.movie.edu
Address:  0.0.0.0

> misery                  -- Look up address
Server:  terminator.movie.edu
Address:  0.0.0.0

Name:    misery.movie.edu
Address:  192.253.253.2

> 192.253.253.2           -- Look up domain name
Server:  terminator.movie.edu
Address:  0.0.0.0

Name:    misery.movie.edu
Address:  192.253.253.2

> set q=mx                -- Look up MX records
> wormhole
Server:  terminator.movie.edu
Address:  0.0.0.0

wormhole.movie.edu      preference = 10, mail exchanger = wormhole.movie.edu
wormhole.movie.edu      internet address = 192.249.249.1
wormhole.movie.edu      internet address = 192.253.253.1

> set q=any               -- Look up records of any type
> diehard
Server:  terminator.movie.edu
Address:  0.0.0.0

diehard.movie.edu       internet address = 192.249.249.4
diehard.movie.edu       preference = 10, mail exchanger = diehard.movie.edu
diehard.movie.edu       internet address = 192.249.249.4

These are only a few of the valid DNS record types, of course. For a more complete list, see Appendix A, "DNS Message Format and Resource Records".

12.5.2. Authoritative Versus Nonauthoritative Answers

If you've used nslookup before, you might have noticed something peculiar -- the first time you look up a remote domain name, the answer is authoritative, but the second time you look up the same name it is nonauthoritative. Here's an example:

% nslookup
Default Server:  relay.hp.com
Address:  15.255.152.2

> slate.mines.colorado.edu.
Server:  relay.hp.com
Address:  15.255.152.2

Name:     slate.mines.colorado.edu
Address:  138.67.1.3

> slate.mines.colorado.edu.
Server:  relay.hp.com
Address:  15.255.152.2

Non-authoritative answer:
Name:    slate.mines.colorado.edu
Address:  138.67.1.3

While this looks odd, it really isn't. What's happening here is that the first time the local name server looks up slate.mines.colorado.edu, it contacts the name server for mines.colorado.edu, and the mines.colorado.edu server then responds with an authoritative answer. The local name server, in effect, passes the authoritative response directly back to nslookup. It also caches the response. The second time you look up slate.mines.colorado.edu, the name server answers out of its cache, which results in the answer "non-authoritative." [96]

[96]BIND 9 name servers, interestingly, show even the first responses as nonauthoritative.

Notice that we terminated the domain name with a trailing dot each time we looked it up. The response would have been the same if we'd left the trailing dot off. There are times when it's critical that you use the trailing dot while debugging, and times when it's not. Rather than stopping to decide if this name needs a trailing dot, we always add one if we know the name is fully qualified, except, of course, if we've turned off the search list.

12.5.3. Switching Name Servers

Sometimes you want to query another name server directly -- you may think it is misbehaving, for example. You can switch servers with nslookup by using the server or lserver command. The difference between server and lserver is that lserver queries your "local" name server -- the one you started out with -- to get the address of the server you want to switch to; server uses the default name server instead of the local server. This difference is important because the server you just switched to may not be responding, as we'll show in this example:

% nslookup
Default Server:  relay.hp.com
Address:  15.255.152.2

When we start up, our first name server, relay.hp.com, becomes our lserver. This will matter later on in this session.

> server galt.cs.purdue.edu.
Default Server:  galt.cs.purdue.edu
Address:  128.10.2.39

> cs.purdue.edu.
Server:  galt.cs.purdue.edu
Address:  128.10.2.39

*** galt.cs.purdue.edu can't find cs.purdue.edu.: No response from server

At this point, we try to switch back to our original name server. But there is no name server running on galt.cs.purdue.edu to look up relay.hp.com's address:

> server relay.hp.com.

*** Can't find address for server relay.hp.com.: No response from server

Instead of being stuck, though, we use the lserver command to have our local name server look up relay.hp.com's address:

> lserver relay.hp.com.
Default Server:  relay.hp.com
Address:  15.255.152.2

> ^D

Since the name server on galt.cs.purdue.edu did not respond -- that host isn't even running a name server -- it wasn't possible to look up the address of relay.hp.com to switch back to using relay 's name server. Here's where lserver comes to the rescue: the local name server, relay, was still responding, so we used it. Instead of using lserver, we also could have recovered by using relay's IP address directly -- server 15.255.152.2.

You can even change servers on a per-query basis. To specify that you'd like nslookup to query a particular name server for information about a given domain name, you can specify the server as the second argument on the line, after the domain name to look up, like so:

% nslookup
Default Server:  relay.hp.com
Address:  15.255.152.2

> saturn.sun.com. ns.sun.com.
Name Server:  ns.sun.com
Address:  192.9.9.3

Name:    saturn.sun.com
Addresses: 192.9.25.2

> ^D

And, of course, you can change servers from the command line. You can specify the server to query as the argument after the domain name to look up, like this:

% nslookup -type=mx fisherking.movie.edu. terminator.movie.edu.

This instructs nslookup to query terminator.movie.edu for MX records for fisherking.movie.edu.

Finally, to specify an alternate default name server and enter interactive mode, you can use a hyphen in place of the domain name to look up:

% nslookup - terminator.movie.edu.

See Also: NsLookup ommand explained in detailOriginal Article Source Here

There are little chores you'll come to use nslookup for almost every day: finding the IP address or MX records for a given domain name, or querying a particular name server for data. We'll cover these first, before moving on to the more occasional stuff.

12.5.1. Looking Up Different Record Types

By default, nslookup looks up the address for a domain name, or the domain name for an address. You can look up any record type by changing the querytype, as we show in this example:

% nslookup
Default Server:  terminator.movie.edu
Address:  0.0.0.0

> misery                  -- Look up address
Server:  terminator.movie.edu
Address:  0.0.0.0

Name:    misery.movie.edu
Address:  192.253.253.2

> 192.253.253.2           -- Look up domain name
Server:  terminator.movie.edu
Address:  0.0.0.0

Name:    misery.movie.edu
Address:  192.253.253.2

> set q=mx                -- Look up MX records
> wormhole
Server:  terminator.movie.edu
Address:  0.0.0.0

wormhole.movie.edu      preference = 10, mail exchanger = wormhole.movie.edu
wormhole.movie.edu      internet address = 192.249.249.1
wormhole.movie.edu      internet address = 192.253.253.1

> set q=any               -- Look up records of any type
> diehard
Server:  terminator.movie.edu
Address:  0.0.0.0

diehard.movie.edu       internet address = 192.249.249.4
diehard.movie.edu       preference = 10, mail exchanger = diehard.movie.edu
diehard.movie.edu       internet address = 192.249.249.4

These are only a few of the valid DNS record types, of course. For a more complete list, see Appendix A, "DNS Message Format and Resource Records".

12.5.2. Authoritative Versus Nonauthoritative Answers

If you've used nslookup before, you might have noticed something peculiar -- the first time you look up a remote domain name, the answer is authoritative, but the second time you look up the same name it is nonauthoritative. Here's an example:

% nslookup
Default Server:  relay.hp.com
Address:  15.255.152.2

> slate.mines.colorado.edu.
Server:  relay.hp.com
Address:  15.255.152.2

Name:     slate.mines.colorado.edu
Address:  138.67.1.3

> slate.mines.colorado.edu.
Server:  relay.hp.com
Address:  15.255.152.2



Non-authoritative answer:
Name:    slate.mines.colorado.edu
Address:  138.67.1.3

While this looks odd, it really isn't. What's happening here is that the first time the local name server looks up slate.mines.colorado.edu, it contacts the name server for mines.colorado.edu, and the mines.colorado.edu server then responds with an authoritative answer. The local name server, in effect, passes the authoritative response directly back to nslookup. It also caches the response. The second time you look up slate.mines.colorado.edu, the name server answers out of its cache, which results in the answer "non-authoritative." [96]

[96]BIND 9 name servers, interestingly, show even the first responses as nonauthoritative.

Notice that we terminated the domain name with a trailing dot each time we looked it up. The response would have been the same if we'd left the trailing dot off. There are times when it's critical that you use the trailing dot while debugging, and times when it's not. Rather than stopping to decide if this name needs a trailing dot, we always add one if we know the name is fully qualified, except, of course, if we've turned off the search list.

12.5.3. Switching Name Servers

Sometimes you want to query another name server directly -- you may think it is misbehaving, for example. You can switch servers with nslookup by using the server or lserver command. The difference between server and lserver is that lserver queries your "local" name server -- the one you started out with -- to get the address of the server you want to switch to; server uses the default name server instead of the local server. This difference is important because the server you just switched to may not be responding, as we'll show in this example:

% nslookup
Default Server:  relay.hp.com
Address:  15.255.152.2

When we start up, our first name server, relay.hp.com, becomes our lserver. This will matter later on in this session.

> server galt.cs.purdue.edu.
Default Server:  galt.cs.purdue.edu
Address:  128.10.2.39

> cs.purdue.edu.
Server:  galt.cs.purdue.edu
Address:  128.10.2.39

*** galt.cs.purdue.edu can't find cs.purdue.edu.: No response from server

At this point, we try to switch back to our original name server. But there is no name server running on galt.cs.purdue.edu to look up relay.hp.com's address:

> server relay.hp.com.

*** Can't find address for server relay.hp.com.: No response from server

Instead of being stuck, though, we use the lserver command to have our local name server look up relay.hp.com's address:

> lserver relay.hp.com.
Default Server:  relay.hp.com
Address:  15.255.152.2

> ^D

Since the name server on galt.cs.purdue.edu did not respond -- that host isn't even running a name server -- it wasn't possible to look up the address of relay.hp.com to switch back to using relay 's name server. Here's where lserver comes to the rescue: the local name server, relay, was still responding, so we used it. Instead of using lserver, we also could have recovered by using relay's IP address directly -- server 15.255.152.2.

You can even change servers on a per-query basis. To specify that you'd like nslookup to query a particular name server for information about a given domain name, you can specify the server as the second argument on the line, after the domain name to look up, like so:

% nslookup
Default Server:  relay.hp.com
Address:  15.255.152.2

> saturn.sun.com. ns.sun.com.
Name Server:  ns.sun.com
Address:  192.9.9.3

Name:    saturn.sun.com
Addresses: 192.9.25.2

> ^D

And, of course, you can change servers from the command line. You can specify the server to query as the argument after the domain name to look up, like this:

% nslookup -type=mx fisherking.movie.edu. terminator.movie.edu.

This instructs nslookup to query terminator.movie.edu for MX records for fisherking.movie.edu.

Finally, to specify an alternate default name server and enter interactive mode, you can use a hyphen in place of the domain name to look up:

% nslookup - terminator.movie.edu.

How to run Pathping

Pathping is a TCP/IP based utility (command-line tool) that provides useful information about network latency and network loss at intermediate hops between a source address and a destination address. It does this by sending echo requests via ICMP and analyzing the results. ICMP stands for Internet Control Message Protocol. ICMP is an extension to the Internet Protocol (IP - part of the TCP/IP protocol suite) defined by RFC 792. ICMP supports packets containing error, control and informational messages. Pathping will send multiple echo request messages to each router between what you are attempting to ping – the source address. If your destination is across a WAN link then it’s certain that you will be using some form of router, most likely two, which would mean that you could test pathping across a two hop network – two router hops. A typical network diagram is seen in the following illustration.

Typical WAN

This is a typical WAN setup which shows you two sites that are connected via a T1 and an Integrated Services Digital Network (ISDN) link. What’s important to see here is that there are multiple paths throughout the network. There is a T1 and an ISDN link. Both technologies connect to each site. The T1 is the main link operating at 1.544 Mbps and the ISDN link is the back up in case the primary fails. Since ISDN is a technology that allows you to pay as you use it, it is a perfect technology to lay dormant until needed. It has less transmission speed (perhaps 64 Kbps), but at the same time, it’s only for emergency so it may be good enough for critical services. The bandwidth drop will add more time for packets to traverse the network and add latency or delay to the traffic. Latency is a measurement of how long it takes for a data packet to get from one point to another. Pathping is a good testing for this element. Latency can be measured by sending a packet as a test that will be returned back to the sender and from that time period - the round-trip time – that is what is considered the latency.

You can use a tool like pathping to see not only if your packets are making it across the network, but are taking the correct preferred path (the T1), or flowing over the alternate link (which would indicate a misconfiguration or a downed link) which is ISDN and, if you have bottlenecks on your network, to see if you have any latency issues. Lack of bandwidth and latency or delay may cause time out issues for your data transmissions. Using the pathping tool you can send multiple echo request messages to each router between you (the source) and your intended destination and after a specific amount of time has elapsed, computes the results from the data that it receives back from each router the packets traversed. Pathping will then display the results.

Syntax

To use pathping, you simply need to open a command prompt on the source system you will run the test from. If you want to use the next illustration as an example, adding an IP address will help you to perform the test. You can see that we have a test PC located at site B and the IP address is 10.1.2.4. This system wants to pathping to site A, a server with an IP address of 10.1.1.5.

Running pathping is easy. Open a command prompt (start -> run -> cmd -> pathping) and type pathping.

As listed here, you can see that the pathping command has many options to include

-n	Prevents pathping from attempting to resolve the IP addresses of intermediate routers to their names. You may want to consider doing this if you think you have a name resolution issue, or if DNS for example is not configured on your system … the time spent trying to contact a name server can be avoided using this switch.
-h	Specifies the maximum number of hops in the path to search for the target (destination). The default is 30 hops.
-p	Specifies the number of milliseconds to wait between consecutive pings. The default is 250 milliseconds (1/4 second).
-q	Specifies the number of Echo Request messages sent to each router in the path. The default is 100 queries.
-w	Specifies the number of milliseconds to wait for each reply. The default is 3000 milliseconds (3 seconds).
/?	Displays help at the command prompt

There are more options, but these are the most commonly used. You can use the help feature to learn more about the options as they are listed in the Windows command prompt.

To use pathping, launch the pathping command from the source to the destination and let pathping do its computation.

D:\>pathping -n server-1 Tracing route to server-1 [10.1.1.5] over a maximum of 30 hops: 0 10.1.2.1 1 10.1.1.1 2 10.1.1.5 Computing statistics for 50 seconds... Source to Here This Node/Link Hop RTT Lost/Sent = Pct Lost/Sent = Pct Address 0 10.1.2.1 0/ 100 = 0% | 1 35ms 0/ 100 = 0% 0/ 100 = 0% 10.1.1.1 13/ 100 = 13% | 2 28ms 16/ 100 = 16% 3/ 100 = 3% 10.1.1.5 0/ 100 = 0% | Trace complete. (some output omitted)

Although in this example, I skimmed it down to the basics and omitted some of the text so we can look right at what we need to know – the statistics and how to read them. In this example, we see that there is a little latency on the second hop, which is 10.1.1.1, traversing the link to the next hop which is 10.1.1.5. In this section we see a small amount of latency which is normal for this size and speed link. If the milliseconds rate were at a very high number, such as 500 ms, then you might consider having a bandwidth issue. As you can see, pathping doesn’t only ‘verify’ connectivity to a destination host, but also, it shows you how your traffic is getting there, and how fast its going, how much resistance its encountering over the wide area network – which is a very common choke point.

Here is another example, but here, I am on a production network machine using pathping to test within a production LAN out to the Internet to a Web server.

When you run pathping, you will also have to be a little patient. Pathping will first display your results as if you were using tracert or traceroute, which is a similar utility to be covered in a separate article. Tracert will show you the ‘path’ through the network as well as verify connectivity but will not show you how the packet is traversing in relation to speed, bandwidth usage and latency. Next (and this is where patience sets in), depending on the hop count (how many router hops that need to be analyzed), check pathping’s results for the Lost/Sent = Pct and Address columns show that the links may either be over utilized (if you have a high drop rate) and so on. The loss rates displayed for the links, identified as a vertical bar (|) in the Address column, indicate link congestion that is causing the loss of packets that are being forwarded on the path. The loss rates displayed for routers (identified by their IP addresses) indicate that these routers may have a problem with overloading or saturation.

Note:
If you see the ‘*’ sign, don’t fret immediately – there may be a firewall blocking ICMP, so you may not get the response although the site is up and responsive. ACL (access control lists) and firewall rule-sets commonly throw off network testers because of this fact. Make sure you know the layout of your network if you are going to troubleshoot it and take this into consideration as it is commonly seen.

Summary

In this article we covered the basics of using pathping. Make sure you visit the links section to learn more about ICMP and how to use pathping. Stay tuned for more articles about how to troubleshoot your production networks!

Original Source Here

How to tell, what to do if computer is infected

Computer-virus infections don't cause your machine to crash anymore.

Nowadays, the criminals behind the infections usually want your computer operating in top form so you don't know something's wrong. That way, they can log your keystrokes and steal any passwords or credit-card numbers you enter at Web sites, or they can link your infected computer with others to send out spam.

Here are some signs your computer is infected, tapped to serve as part of "botnet" armies run by criminals:

• You experience new, prolonged slowdowns. This can be a sign that a malicious program is running in the background.

• You continually get pop-up ads that you can't make go away. This is a sure sign you have "adware," and possibly more, on your machine.

• You're being directed to sites you didn't intend to visit, or your search results are coming back funky. This is another sign that hackers have gotten to your machine.

So what do you do?

• Having anti-virus software here is hugely helpful. For one, it can identify known malicious programs and disable them. If the virus that has infected your machine isn't detected, many anti-virus vendors offer a service in which they can remotely take over your computer and delete the malware for a fee.

• Some anti-virus vendors also offer free, online virus-scanning services.

• You may have to reinstall your operating system if your computer is still experiencing problems. It's a good idea even if you believe you've cleaned up the mess because malware can still be hidden on your machine. You will need to back up your files before you do this.



How do I know what information has been taken?

• It's very hard to tell what's been taken. Not every infection steals your data. Some just serve unwanted ads. Others poison your search result or steer you to Web sites you don't want to see. Others log your every keystroke. The anti-virus vendors have extensive databases about what the known infections do and don't do. Comparing the results from your virus scans to those entries will give you a good idea about what criminals may have snatched up.

Original Source: YahooTech Here

Ping command explained

Sources: Wiki, Microsoft

Ping is a computer network tool used to test whether a particular host is reachable across an IP network; it is also used to self test the network interface card of the computer, or as a speed test. It works by sending ICMP “echo request” packets to the target host and listening for ICMP “echo response” replies. Ping measures the round-trip time^[1] and records any packet loss, and prints when finished a statistical summary of the echo response packets received, the minimum, mean, max and in some versions the standard deviation of the round trip time.

The word ping is also frequently used as a verb or noun, where it is usually incorrectly used to refer to the round-trip time, or measuring the round-trip time.

If you are having connectivity problems, you can use the ping command to check the destination IP address you want to reach and record the results. The ping command displays whether the destination responded and how long it took to receive a reply. If there is an error in the delivery to the destination, the ping command displays an error message.

You can use the ping command to:

* Ping your computer (by address, not host name) to determine that TCP/IP is functioning. (Pinging your computer does not verify that your network adapter is functioning.)
* Ping the local router to determine whether the router is running.
* Ping beyond your local router.

The following table shows some useful ping command options.

Option Use

-nCount


Determines the number of echo requests to send. The default is 4 requests.

-wTimeout


Enables you to adjust the time-out (in milliseconds). The default is 1,000 (a 1-second time-out).

-lSize


Enables you to adjust the size of the ping packet. The default size is 32 bytes.

-f


Sets the Do Not Fragment bit on the ping packet. By default, the ping packet allows fragmentation.

The following example illustrates how to send two pings, each 1,450 bytes in size, to IP address 131.107.8.1:
Copy Code

C:\>ping -n 2 -l 1450 131.107.8.1
Pinging 131.107.8.1 with 1450 bytes of data:

Reply from 131.107.8.1: bytes=1450 time<10ms ttl="32" bytes="1450" ttl="32" sent =" 2," received =" 2," lost =" 0" minimum =" 0ms," maximum =" 10ms," average =" 2ms" href="http://technet.microsoft.com/en-us/library/cc737478.aspx">here

Ping command History Explained

A server denying a ping request because of the request's size.

Mike Muuss wrote the program in December, 1983, as a tool to troubleshoot odd behavior on an IP network. He named it after the pulses of sound made by a sonar, since its operation is analogous to active sonar in submarines, in which an operator issues a pulse of energy at the target, which then bounces from the target and is received by the operator. (The pulse of energy in sonar is analogous to a network packet in ping). ^[1][2]

The usefulness of ping in assisting the "diagnosis" of Internet connectivity issues was impaired from late in 2003, when a number of Internet Service Providers began filtering out ICMP Type 8 (echo request) messages at their network boundaries.

This was partly due to the increasing use of ping for target reconnaissance, for example by Internet worms such as Welchia that flood the Internet with ping requests in order to locate new hosts to infect. Not only did the availability of ping responses leak information to an attacker, it added to the overall load on networks, causing problems for routers across the Internet.

Although RFC 1122 prescribes that any host must accept an echo-request and issue an echo-reply in return, this is supposedly a security risk. Thus, hosts that no longer follow this standard are frequent on the public Internet.

ICMP packet

ICMP packet

	Bit 0 - 7	Bit 8 - 15	Bit 16 - 23	Bit 24 - 31
IP Header (160 bits OR 20 Bytes)	Version/IHL	Type of service	Length
	Identification		flags and offset
	Time To Live(TTL)	Protocol	Checksum
	Source IP address
	Destination IP address
ICMP Payload (64+ bits OR 8+ Bytes)	Type of message	Code	Checksum
	Quench
	Data (optional)

Generic composition of an ICMP packet

• Header (in blue):
  • Protocol set to 1 and Type of Service set to 0.
• Payload (in red):
  • Type of ICMP message (8 bits)
  • Code (8 bits)
  • Checksum (16 bits), calculated with the ICMP part of the packet (the header is not used)
  • The ICMP 'Quench' (32 bits) field, which in this case (ICMP echo request and replies), will be composed of identifier (16 bits) and sequence number (16 bits).
  • Data load for the different kind of answers (Can be an arbitrary length, left to implementation detail. However must be less than the maximum MTU of the network^{[citation needed]}).

Sample pinging

Sample with Linux

The following is a sample output of pinging en.wikipedia.org under Linux with the iputils version of ping:

admin@localhost# ping en.wikipedia.org
PING rr.pmtpa.wikimedia.org (66.230.200.100) 56(84) bytes of data.
64 bytes from rr.pmtpa.wikimedia.org (66.230.200.100): icmp_seq=1 ttl=52 time=87.7 ms
64 bytes from rr.pmtpa.wikimedia.org (66.230.200.100): icmp_seq=2 ttl=52 time=95.6 ms
64 bytes from rr.pmtpa.wikimedia.org (66.230.200.100): icmp_seq=3 ttl=52 time=85.4 ms
64 bytes from rr.pmtpa.wikimedia.org (66.230.200.100): icmp_seq=4 ttl=52 time=95.8 ms
64 bytes from rr.pmtpa.wikimedia.org (66.230.200.100): icmp_seq=5 ttl=52 time=87.0 ms
64 bytes from rr.pmtpa.wikimedia.org (66.230.200.100): icmp_seq=6 ttl=52 time=97.6 ms

--- rr.pmtpa.wikimedia.org ping statistics ---
10 packets transmitted, 10 received, 0% packet loss, time 8998ms
rtt min/avg/max/mdev = 78.162/89.213/97.695/6.836 ms

This output shows that en.wikipedia.org is a DNS CNAME record for rr.pmtpa.wikimedia.org which then resolves to 66.230.200.100.

The output then shows the results of making 10 pings to 66.230.200.100 with the results summarized at the end. (To stop the program in Linux or Windows, press Ctrl+C.)

• shortest round trip time was 78.162 milliseconds
• average round trip time was 89.213 milliseconds
• maximum round trip time was 97.695 milliseconds
• Standard deviation of the round-trip time was 6.836 milliseconds

While a ping session is running, under some Linux systems, you can get the overall status of the session without quitting by sending the Ctrl+\ key combination. This will give you a summary similar to the following.

6/6 packets, 0% loss, min/avg/ewma/max = 15.304/23.188/20.446/53.673 ms

Sample with Windows

The following is a sample output of pinging en.wikipedia.org under Windows (Vista used in the following example) from within the Command Prompt:

[localhost] ping en.wikipedia.org
Pinging rr.pmtpa.wikimedia.org [66.230.200.100] with 32 bytes of data:
Reply from 66.230.200.100: bytes=32 time=57ms TTL=44
Reply from 66.230.200.100: bytes=32 time=59ms TTL=44
Reply from 66.230.200.100: bytes=32 time=59ms TTL=44
Reply from 66.230.200.100: bytes=32 time=54ms TTL=44

Ping statistics for 66.230.200.100:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 54ms, Maximum = 59ms, Average = 57ms

Windows appears not to inform the user about duplicated return packets.

While a ping session is running you can get the overall status of the session without quitting by sending the Ctrl+Break key combination.

Sample with Mac OS X

The following is a sample output of pinging en.wikipedia.org under Mac OS X Leopard using the Terminal:

Macintosh:~ user$ ping -c 10 en.wikipedia.org
PING rr.knams.wikimedia.org (91.198.174.2): 56 data bytes
64 bytes from 91.198.174.2: icmp_seq=0 ttl=53 time=40.019 ms
64 bytes from 91.198.174.2: icmp_seq=1 ttl=53 time=47.502 ms
64 bytes from 91.198.174.2: icmp_seq=2 ttl=53 time=43.208 ms
64 bytes from 91.198.174.2: icmp_seq=3 ttl=53 time=50.851 ms
64 bytes from 91.198.174.2: icmp_seq=4 ttl=53 time=46.556 ms
64 bytes from 91.198.174.2: icmp_seq=5 ttl=53 time=42.180 ms
64 bytes from 91.198.174.2: icmp_seq=6 ttl=53 time=49.853 ms
64 bytes from 91.198.174.2: icmp_seq=7 ttl=53 time=45.556 ms
64 bytes from 91.198.174.2: icmp_seq=8 ttl=53 time=41.186 ms
64 bytes from 91.198.174.2: icmp_seq=9 ttl=53 time=48.836 ms

--- rr.knams.wikimedia.org ping statistics ---
10 packets transmitted, 10 packets received, 0% packet loss
round-trip min/avg/max/stddev = 40.019/45.575/50.851/3.588 ms

While a ping session is running you can get the overall status of the session without quitting by sending the Ctrl+t key combination. This will give you a summary similar to the following.

load: 0.37  cmd: ping 1748 running 0.01u 0.07s
255/255 packets received (100%) 18.827 min / 19.975 avg / 29.200 max

Message format

Echo request

The echo request is an ICMP message whose data is expected to be received back in an echo reply ("pong"). The host must respond to all echo requests with an echo reply containing the exact data received in the request message.

00	01	02	03	04	05	06	07	08	09	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Type = 8								Code = 0								Header Checksum
Identifier																Sequence Number
Data :::

• Type must be set to 8.
• Code must be set to 0.
• The Identifier and Sequence Number can be used by the client to match the reply with the request that caused the reply. In practice, most Linux systems use a unique identifier for every ping process, and sequence number is an increasing number within that process. Windows uses a fixed identifier, which varies between Windows versions, and a sequence number that is only reset at boot time.
• The data received by the Echo Request must be entirely included in the Echo Reply.

Echo reply

The echo reply is an ICMP message generated in response to an echo request, and is mandatory for all hosts and routers.

00	01	02	03	04	05	06	07	08	09	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Type = 0								Code = 0								Header Checksum
Identifier																Sequence Number
Data :::

• Type and code must be set to 0.
• The identifier and sequence number can be used by the client to determine which echo requests are associated with the echo replies.
• The data received in the echo request must be entirely included in the echo reply.

Payload

The payload of the packet is generally filled with letters of the alphabet as this ASCII tcpdump shows

16:24:47.966461 IP (tos 0x0, ttl 128, id 15103, offset 0, flags [none], proto: ICMP (1), length: 60) 192.168.146.22 > 192.168.144.5: ICMP echo request, id 1, seq 38, length 40

      0x0000:  4500 003c 3aff 0000 8001 5c55 c0a8 9216  E..<:.....\U....      0x0010:  c0a8 9005 0800 4d35 0001 0026 6162 6364  ......M5...&abcd      0x0020:  6566 6768 696a 6b6c 6d6e 6f70 7172 7374  efghijklmnopqrst      0x0030:  7576 7761 6263 6465 6667 6869            uvwabcdefghi 

In gaming

Main article: ping (video games)

In network multiplayer games like Left 4 Dead, Unreal Tournament, Quake, Battlefield, Call of Duty, Counter Strike, Combat Arms, Halo,Gunz etc., the server notes the time it requires for a game packet to reach a client and a response to be received. This round-trip time is usually reported as the player's 'ping'. It is used as an effective measurement of the player's lag, with lower ping times being desirable. Note that this style of ping typically does not use ICMP packets.

See also

• bing, ping with added throughput measurements
• dping, AIX command included in IBM Cluster Systems Management for sending ICMP packets to multiple hosts in parallel
• fping, command for sending ICMP packets to multiple hosts in parallel
• List of DOS commands
• List of Unix programs
• Ping of death
• Ping (video games)
• Traceroute, mtr (My traceroute)

References

1. ^ ^{a b} "The Story of the PING Program". http://ftp.arl.mil/~mike/ping.html. Retrieved on 29 December 2008.
2. ^ Salus, Peter (1994). A Quarter Century of UNIX. Addison-Wesley. ISBN 0201547775.

• RFC 792

External links

• ping(1): send ICMP ECHO_REQUEST to network hosts – Linux man page
• Ping Animation

Use of uppercase hostname in nslookup

Host name resolution considerations

Original Article Source Here

In a Kerberos environment, both the client and the server use some method of host name resolution to determine the host name for the system on which a particular application or service resides. If the iSeries™ servers and the PCs use a Domain Name System (DNS) server, it is important that they use the same DNS server to perform host name resolution or, if they use more than one DNS server, that the host names are the same on both DNS servers. If your iSeries system or PC resolve host names locally (from a local host table or file) they might resolve a host name that is different than the corresponding host name recorded on the DNS server. This might cause network authentication service to fail.

To ensure that Kerberos authentication and host name resolution work properly with your Kerberos enabled applications, you must verify that your PCs and your iSeries servers resolve the same host name for the system on which the service application resides. In the following example, this system is called iSeries A.

The following instructions demonstrate how to determine whether the PCs and iSeries systems resolve the same name for iSeries A. Refer to the example work sheets as you follow the instructions.

You can enter your own information in the blank work sheets when you perform these steps for your Kerberos realm.

This graphic illustrates the system files and records that contain host name information in the following example.

Note: The IP address 10.1.1.1 represents a public IP address. This address is for example purposes only.

Details

DNS server

• Contains data resource records that indicate that IP address 10.1.1.1 correlates to host name iseriesa.myco.com, the IP address and host name for iSeries A.
• May be used by the PC, iSeries A, or both for host resolution.
  Note: This example demonstrates one DNS server. However, your network may use more than one DNS server. For example, your PC may use one DNS server to resolve host names and your iSeries server may use a different DNS server. You need to determine how many DNS servers your realm is using for host resolution and adapt this information to your situation.

PC

• Runs Windows^® 2000 operating system.
• Represents both the PC used to administer network authentication service and the PC used by a user with no special authorities for his routine tasks.
• Contains the hosts file which indicates that IP address 10.1.1.1 correlates to host name iseriesa.myco.com.
  Note: You can find the hosts file in these folders:

  • Windows 2000 operating system: C:\WINNT\system32\drivers\etc\hosts
  • Windows XP operating system: C:\WINDOWS\system32\drivers\etc\hosts

iSeries A

• Runs i5/OS^® Version 5 Release 3 (V5R3).
• Contains a service application that you need to access using network authentication service (Kerberos authentication).
• Within the CFGTCP (Configure TCP) menu, options 10 and 12 indicate the following information for iSeries A:
  • Option 10 (Work with TCP/IP host table entries):
    • Internet Address: 10.1.1.1
    • Host Name: iseriesa.myco.com
  • Option 12 (Change TCP/IP domain information):
    • Host name: iseriesa
    • Domain name: myco.com
    • Host name search priority: *LOCAL or *REMOTE
      Note: The Host name search priority parameter indicates either *LOCAL or *REMOTE depending on how your network administrator configured TCP/IP to perform host resolution on the server.

Table 1. Example: PC host name resolution work sheet

On the PC, determine the host name for iSeries A
Step	Source	Host name
1.a.1	PC hosts file	iseriesa.myco.com
1.b.1	DNS server	iseriesa.myco.com

Table 2. Example: iSeries host name resolution work sheet

On iSeries A, determine the host name for iSeries A
Step	Source	Host name
2.a.2	iSeries A CFGTCP option 12	Host name: iseriesa Domain name: myco.com
Note: Host name search priority value: *LOCAL or *REMOTE
2.b.2	iSeries A CFGTCP option 10	iseriesa.myco.com
2.c.1	DNS server	iseriesa.myco.com

Table 3. Example: Matching host names work sheet

These three host names must match exactly
Step	Host name
Step 1	iseriesa.myco.com
Step 2.a.2	iseriesa myco.com
2d	iserisa.myco.com

Table 4. PC host name resolution work sheet

On the PC, determine the host name for the iSeries server
Step	Source	Host name
1.a.1	PC hosts file
1.b.1	DNS server

Table 5. iSeries host name resolution work sheet

On your iSeries server, determine the host name for the iSeries
Step	Source	Host name
2.a.2	iSeries CFGTCP option 12	Host name: Domain name:
Note Host name search priority value: *LOCAL or *REMOTE
2.b.2	iSeries CFGTCP option 10
2.c.1	DNS server

Table 6. Matching host names work sheet

These three host names must match exactly
Step	Host name
Step 1
Step 2.a.2
2d

To verify that the PCs and iSeries systems are resolving the same host name for iSeries A, follow these steps:

1. From the PC, determine the fully qualified TCP/IP host name for iSeries A.
   Note: Depending on how you manage your network, you may want to do this on other PCs that are joining the single signon environment.
   1. In Windows Explorer on the PC, open the hosts file from one of these locations:
      • Windows 2000 operating system: C:\WINNT\system32\drivers\etc\hosts
      • Windows XP operating system: C:\WINDOWS\system32\drivers\etc\hosts
      Note: If the hosts file does not exist on the PC, then your PC may be using a DNS server to resolve host names. In that case, skip to Step 1b.
      1. On the work sheet, write down the first host name entry for iSeries A, noting the uppercase or lowercase characters. For example, iseriesa.myco.com.
         Note: If the hosts file does not contain an entry for iSeries A, then your PC may be using a DNS server to resolve host names. In that case, see Step 1b.
   2. Use NSLOOKUP to query the DNS server.
      Note: Skip this step if you found a host name entry in the PC's hosts file, and proceed to Step 2. (The hosts file takes precedence over DNS servers when the operating system resolves host names for the PC.)
      1. At a command prompt, type NSLOOKUP and press Enter. At the NSLOOKUP prompt, type 10.1.1.1 to query the DNS server for iSeries A. Write down the host name returned by the DNS server, noting the uppercase or lowercase characters. For example, iseriesa.myco.com.
      2. At the NSLOOKUP prompt, type iseriesa.myco.com. This must be the host name returned by the DNS server in the previous step. Verify that the DNS server returns the IP address that you expect. For example, 10.1.1.1.
         Note: If NSLOOKUP does not return the expected results, your DNS configuration is incomplete. For example, if NSLOOKUP returns an IP address that is different than the address you entered in Step 1.b.1, you need to contact the DNS administrator to resolve this problem before you can continue with the next steps.
2. From iSeries A, determine its fully qualified TCP/IP host name.
   1. TCP/IP domain information
      1. At the command prompt, type CFGTCP and select Option 12 (Change TCP/IP domain).
      2. Write down the values for the Host name parameter and the Domain name parameter, noting the uppercase or lowercase characters. For example:
         • Host name: iseriesa
         • Domain name: myco.com
      3. Write down the value for the Host name search priority parameter.
         • *LOCAL - The operating system searches the local host table (equivalent of hosts file on the PC) first. If there is not a matching entry in the host table and you have configured a DNS server, the operating system then searches your DNS server.
         • *REMOTE - The operating system searches the DNS server first. If there is not a matching entry in the DNS server, the operating system then searches the local host table.
   2. TCP/IP host table
      1. At the command prompt, type CFGTCP and select Option 10 (Work with TCP/IP Host Table Entries).
      2. Write down the value in the Host Name column that corresponds to iSeries A (IP address 10.1.1.1), noting the uppercase or lowercase characters. For example, iseriesa.myco.com.
         Note: If you do not find an entry for iSeries A in the host table, proceed to the next step.
   3. DNS server
      1. At a command prompt, type NSLOOKUP and press Enter. At the NSLOOKUP prompt, type 10.1.1.1 to query the DNS server for iSeries A. Write down the host name returned by the DNS server, noting the uppercase or lowercase characters. For example, iseriesa.myco.com.
      2. At the NSLOOKUP prompt, type iseriesa.myco.com. This must be the host name returned by the DNS server in the previous step. Verify that the DNS server returns the IP address that you expect. For example, 10.1.1.1.
         Note: If NSLOOKUP does not return the expected results, your DNS configuration is incomplete. For example, if NSLOOKUP returns an IP address that is different than the address you entered in Step 2.c.1, you need to contact the DNS administrator to resolve this problem before you can continue with the next steps.
   4. Determine which host name value for iSeries A to keep, based on its TCP/IP configuration.
      • If the value for the Host name search priority parameter is *LOCAL, keep the entry noted from the local host table (Step 2.b.2).
      • If the value for the Host name search priority parameter is *REMOTE, keep the entry noted from the DNS server (Step 2.c.1).
      • If only one of these sources contains an entry for iSeries A, keep that entry.
3. Compare the results from these steps:
   • Step 1 - Name that the PC uses for iSeries A.
     Note: If you found an entry for iSeries A in the PC's hosts file, use that entry. Otherwise, use the entry from the DNS server.
   • Step 2.a.2 - Name that iSeries A calls itself within its TCP/IP configuration.
   • Step 2d - Name that iSeries A calls itself based on host name resolution.

   All three of these entries must match exactly, including uppercase and lowercase characters. If the results do not exactly match, you will receive an error message indicating that a keytab entry cannot be found.

See Also: NsLookup ommand explained in detail

Tracert command and windows ports icluding port 80

Original Article Source Here

Understanding Traceroute
By Brian Dennis, CCIE #2210

First off we need to understand that traceroute is a technique to have the routers between the source and destination reveal themselves and finally have the destination reveal itself. Traceroute can be implemented using ICMP, UDP, and even TCP so as a CCIE when someone asks you to filter “traceroute” you should get a little background as to the traceroute application/OS’s being used to trigger the reply from the destination. Example: Windows uses ICMP echoes by default, most Linux OS’s use UDP by default but can use ICMP echoes (-I option), and the IOS uses UDP. There are also implementations that use TCP.

The goal of traceroute is to have the routers between the source and destination reveal themselves and finally have the destination reply so that you know you have reached it. The routers reveal themselves by sending Time Exceeded (aka TTL-Exceeded) ICMP packets back to the source when the TTL is decremented to zero. The traceroute implementation can determine its reached the destination by having it reply to an ICMP echo request, send an ICMP port unreachable to a packet sent to an unused UDP port, or completing the TCP three-way handshake.

************************************************************************

ICMP based traceroute:

In this example we are sending ICMP echo requests to www.cisco.com and looking for the ICMP echo reply to know that we have reached the final destination.

[root@digdug root]# traceroute -I www.cisco.com
traceroute to www.cisco.com (198.133.219.25), 30 hops max, 38 byte
packets
1 198.132.102.1 (198.132.102.1) 1.658 ms 1.975 ms 1.968 ms
2 foo.hostrack.net (202.101.143.254) 5.394 ms 22.382 ms 2.966 ms
3 ser4-0.core01.las.switchcommgroup.com (66.209.64.41) 20.132 ms 20.494 ms 20.195 ms
4 pos1-0.core02.las.oc48a.switchcommgroup.com (66.209.64.218) 19.749 ms 25.827 ms 26.814 ms
5 500.POS4-0.GW1.VEG2.alter.net (157.130.238.193) 29.108 ms 19.864 ms 20.066 ms
6 129.at-0-0-0.CL1.PHX2.ALTER.NET (152.63.115.26) 26.338 ms 26.232 ms 26.821 ms
7 0.so-4-0-0.XL1.SJC2.ALTER.NET (152.63.55.101) 46.424 ms 45.996 ms 45.675 ms
8 POS1-0.XR1.SJC2.ALTER.NET (152.63.56.138) 48.653 ms 46.513 ms 46.803 ms
9 193.ATM7-0.GW5.SJC2.ALTER.NET (152.63.48.77) 46.693 ms 46.619 ms 46.446 ms
10 ciscosys-gw1.customer.alter.net (65.208.80.242) 46.556 ms 46.954 ms 46.944 ms
11 sjce-dmzbb-gw1.cisco.com (128.107.239.89) 30.818 ms 31.769 ms 32.685 ms
12 sjck-dmzdc-gw1.cisco.com (128.107.224.69) 30.589 ms 30.626 ms 30.448 ms
13 * * *
14 www.cisco.com (198.133.219.25) 28.916 ms 28.994 ms 28.944 ms
************************************************************************

UDP based traceroute:
In this example we are sending UDP packets with a starting port number of 33434 to www.cisco.com. Note that we don’t ever get a reply from www.cisco.com because their firewall will not allow our UDP packets to arbitrary high ports in.

[root@digdug root]# man traceroute | grep “UDP port number”
-p Set the base UDP port number used in probes (default is 33434).
[root@digdug root]#
[root@digdug root]# traceroute www.cisco.com
traceroute to www.cisco.com (198.133.219.25), 30 hops max, 38 byte packets
1 198.132.102.1 (198.132.102.1) 1.725 ms 1.866 ms 1.841 ms
2 foo.hostrack.net (202.101.143.254) 4.887 ms 4.281 ms 4.482 ms
3 ser4-0.core01.las.switchcommgroup.com (66.209.64.41) 21.266 ms 21.152 ms 20.826 ms
4 pos1-0.core02.las.oc48a.switchcommgroup.com (66.209.64.218) 58.829 ms 42.033 ms 24.007 ms
5 500.POS4-0.GW1.VEG2.alter.net (157.130.238.193) 21.448 ms 23.277 ms 21.446 ms
6 129.at-0-0-0.CL1.PHX2.ALTER.NET (152.63.115.26) 27.816 ms 27.259 ms 27.210 ms
7 0.so-4-0-0.XL1.SJC2.ALTER.NET (152.63.55.101) 47.540 ms 46.954 ms 47.198 ms
8 POS1-0.XR1.SJC2.ALTER.NET (152.63.56.138) 48.072 ms 47.247 ms 46.667 ms
9 193.ATM7-0.GW5.SJC2.ALTER.NET (152.63.48.77) 51.728 ms 51.437 ms 48.304 ms
10 ciscosys-gw1.customer.alter.net (65.208.80.242) 48.563 ms 48.878 ms 47.807 ms
11 sjce-dmzbb-gw1.cisco.com (128.107.239.89) 31.562 ms 32.653 ms 31.318 ms
12 sjck-dmzdc-gw1.cisco.com (128.107.224.69) 32.327 ms 31.831 ms 31.516 ms
13 * * *
14 * * *

************************************************************************
TCP based traceroute:

In this example we are sending TCP SYN packets to port 80 looking for the destination to complete the three-way-handshake. Once the handshake
is complete we know that we have reached the destination. Obviously Cisco’s firewall is going to allow packets to TCP port 80 destined for it’s web server.

[root@digdug root]# tcptraceroute www.cisco.com
tcptraceroute: Symbol `pcap_version’ has different size in shared object, consider re-linking
Selected device eth3, address 198.132.102.93, port 41440 for outgoing packets
Tracing the path to www.cisco.com (198.133.219.25) on TCP port 80, 30 hops max
1 198.132.102.1 (198.132.102.1) 1.575 ms 1.507 ms 1.469 ms
2 foo.hostrack.net (202.101.143.254) 4.840 ms 5.090 ms 4.596 ms
3 ser4-0.core01.las.switchcommgroup.com (66.209.64.41) 21.205 ms 20.895 ms 21.430 ms
4 pos1-0.core02.las.oc48a.switchcommgroup.com (66.209.64.218) 21.682 ms 21.012 ms 21.059 ms
5 500.POS4-0.GW1.VEG2.alter.net (157.130.238.193) 21.185 ms 21.304 ms 20.939 ms
6 129.at-0-0-0.CL1.PHX2.ALTER.NET (152.63.115.26) 27.176 ms 28.615 ms 27.644 ms
7 0.so-4-0-0.XL1.SJC2.ALTER.NET (152.63.55.101) 47.659 ms 48.220 ms 47.667 ms
8 POS1-0.XR1.SJC2.ALTER.NET (152.63.56.138) 47.534 ms 48.483 ms 47.183 ms
9 193.ATM7-0.GW5.SJC2.ALTER.NET (152.63.48.77) 64.413 ms 51.058 ms 49.007 ms
10 ciscosys-gw1.customer.alter.net (65.208.80.242) 48.156 ms 49.197 ms 47.534 ms
11 sjce-dmzbb-gw1.cisco.com (128.107.239.89) 31.685 ms 32.633 ms32.895 ms
12 sjck-dmzdc-gw1.cisco.com (128.107.224.69) 32.291 ms 33.900 ms35.461 ms
13 www.cisco.com (198.133.219.25) [open] 31.041 ms 31.667 ms 32.775 ms
[root@digdug root]#


Please See Also
Tracert ommand explained

Optimal memory for windows vista

Windows vista is a resource hungry Windows especially in terms of memory. With the memory devices becoming cheaper and prices are continuously falling for hard disks and rams, it is easier to upgrade your system memory and run windows vista

Hard disk memory requirements
The optimal permanent storage or hard disk memory requirements for windows vista is at least 20 GB. Windows vista, itself will take up to 5 GB hard disk space but you need page file as well. Consider this formula to detect the size of page file. (Your memory X 1.5) + 100. Let us suppose that you have a memory module of 500 MB then the optimal size of your page will be (500 X 1.5) +100 = 850 MB. It means you will need 5 GB + 850 MB = 5.9 GB optimal hard disk memory to run windows vista. An urban myth says half of your C drive should be empty for optimal Windows Vista performance, so you reach 12 GB. But you did not yet add all the programs in it. So add them and you get somewhere between 20 GB – 30 GB. It means, make your primary partition of 20 – 30 GB at least.

RAM requirements
Windows Vista has a lot of processes going on through it. All of the processes reside in the RAM and utilize this volatile memory to achieve optimal Windows Vista performance. If you are need a normal usage, at least 1. 5 GB memory is required. You can get a 1 GB memory module and a 512 MB memory module to run Windows Vista. To be on the safe side, get at least 2 GB memory if you want Vista to run at smooth speed with different office and business applications.

Graphics requirements
Windows Vista uses a heavy graphics interface called Aero Interface. If you disable it, you take the fun out but in order to run it at a good speed, you must have a graphics accelerator device. Most motherboards have now built in graphics accelerator devices but if you are using an older board, I suggest you get a GPU. You can even use a second hand GPU which is in the 30$ range or even less. A 128 MB memory GPU will be enough for you. For more information about graphics memory, you can visit the following article

How to run Windows Vista at Optimum speed in 80$

Change subnet mask from command prompt

In windows, changing the subnet mask from command prompt is fairly easy and simple. Although many people make it a different job, yet it is in fact easy. Subnet mask itself is the network definer. It defines the network address. Remember, IP address and network addresses are two different things.

In order to change the subnet mask from the command prompt, you should have two things things

1. Your IP address
2. Subnet mask.

If you want to change your subnet mask use the netsh command

Procedure to change subnet mask from the command prompt

Click Start
In windows XP click run and in Windows Vista use the direct run box above start icon
Type cmd and hit enter
If you are using windows vista, after you type cmd, cmd.ee will be shown above. Just right click on it and click run as Administrator
After that type in the following command there

netsh interface ip set address "interface name" static [ip address] [subnet mask] [gateway]

Let us suppose you want to have an ip of 192.168.1.179 with a subnet of /24 or 255.255.255.0

Type this command in the command prompt and hit enter
netsh interface ip set address "E1" static 192.168.1.179 255.255.255.0 192.168.1.1

When you type this command, you will have successfully changed your subnet mask from the command prompt. Enjoy
You can also check the following

Change IP address from command prompt

How to change the appearence of Windows?

Have your computer been running slow lately? Are you running the prestigious yet resource hungry Microsoft operating system like Windows XP or Windows Vista? Wel if the answer is yes then you may be a victim to classic Microsoft-do-it-slow phobia. In case you are wondering what the hell is that then the imple answerwould be that microsoft operating systems tend to ecome slow with time but that is not the biggest issu. The biggest issue is that if you do not have a tip top pc then beeive it or not, ytou shouldnt try windows vista and even XP is a mess at times.

I am not saying that you should not run a Windows operating system specially Windows XP or Windows Vista but the thing is that you need a realy fast PC with a good graphics processing unit a.k.a graphics accelerator.

If you do not know what graphics cards are then you can read this to set up your graphics card and Why updating your drivers is important so that you know you get the best out of your PC.

Well let us assume that you can not afford or do not want to buy something and still want to use windows vista or windiws XP for some weird reason then my suggestion would be to change the appearence of your Windows. Appearence is provided to give a different look and feel to your computer but these appearence settings serve more than that.

In Windows XP or Vista, you can right click on an empty space on your desktop and click Properties. In XP a new settings window will open with different tabs. You can select the themes tab and select Windiws Classic theme. If you are running Windows Vista, as soon as you hit the properties tab, you are offered a full page of mindblowing options. Select themes and change the theme to windows Classic. Once you do that, your settings and appearence will be changed to Pre-Windows XP style.

If, for any unknown ewason, you cant see themes in any of these Windows, then now is the time to look for appearence tab in XP or Windows color and appearence link in Vista. In XP, select the windiws classic style and you can see different classic style shades and color. For Vista, you have to use advanced ptions from the appearence link. You will see the same page as XP to select Classic appearence settings instead of the Aero Interface. Change it and make your life easy with less graphics andd fast perormance. Hurray

Security threat, Koobface, Other Worms Target Facebook Friends

Koobface, Other Worms Target Facebook Friends (NewsFactor)


Referenced by Yahoo Tech: Original Source Here

- As Facebook works to make itself more relevant and timely for its growing member base with a profile page makeover, attackers seem to be working overtime to steal the identities of the friends, fans and brands that connect though the social-networking site.

Indeed, Facebook has seen five different security threats in the past week. According to Trend Micro, four new hoax applications are attempting to trick members into divulging their usernames and passwords. And a new variant of the Koobface worm is running wild on the site, installing malware on the computers of victims who click on a link to a fake YouTube video.

The Koobface worm is dangerous. It can be dropped by other malware and downloaded unknowingly by a user when visiting malicious Web sites, Trend Micro reports. When attackers execute the malware, it searches for cookies created by online social networks. The latest variant is targeting Facebook, but earlier variants have also plagued MySpace.

Koobface's Wicked Agenda

Once Koobface finds the social-networking cookies, it makes a DNS query to check IP addresses that correspond to remote domains. Trend Micro explains that those servers can send and receive information about the affected machine. Once connected, the malicious user can remotely perform commands on the victim's machine.

"Once cookies related to the monitored social-networking Web sites are located, it connects to these Web sites using the user log-in session stored in the cookies. It then navigates through pages to search for the user's friends. If a friend has been located, it sends an HTTP POST request to the server," Trend Micro reports.

Ultimately, the worm's agenda is to transform the victim's computer into a zombie and form botnets for malicious purposes. Koobface attempts to do this by composing a message and sending it to the user's friends. The message contains a link to a Web site where a copy of the worm can be downloaded by unsuspecting friends. And the cycle repeats itself.

An Attractive Face(book)

Malware authors are investing more energy in Facebook and other social-networking sites because that effort pays off, according to Michael Argast, a security analyst at Sophos. Facebook alone has more than 175 million users, which makes it an attractive target.

"Many computer users have been conditioned not to open an attachment from an e-mail or click a link found within, but won't think twice about checking out a hot new video linked to by a trusted friend on Facebook," Argast said.

Argast called the Koobface worm a mix of something old and something new. The new is using social networks as a method to spread malware. The old is using fake codec Trojans linked to a saucy video to induce the user to install the malware.

Argast said people can protect themselves by running up-to-date antivirus software, restricting which Facebook applications they install, thinking twice before clicking on links from friends and never, never installing a codec from some random Web site in the hopes of catching some celebrity in a compromised situation.

"I would expect to see more attacks on Facebook," Argast said. "As long as this is a successful propagation method, the bad guys will double down and invest more. They are entirely motivated by financial gain. If it pays, they'll continue to romp in your social playgrounds."

Complete MP3 songs from the movie Jai Veeru

Here is a list of the complete list of songs from the indian movie "Jai Veeru". This is a good and interesting movie with nicely developed characters and roles. If you are interested in downloading songs of the movie "Jai Veeru" then this is the place. Download latest and new complete songs now.

To download a song from Jai Veeru

Internet Explorer
Right click on the song name from movie "Jai Veeru" and click "Save Target As" and select the location to save file.

Fire Fox
Right click on the song name from movie "Jai Veeru" and click "Save Target As" and select the location to save file.


Check the right links for other movies and songs. Try now "Jai Veeru"

	Sufi Tere Pyaar Mein	Media Player-128 Kbps
	Aisa Lashkara	Media Player-128 Kbps
	Agre Ka Ghagra	Media Player-128 Kbps
	Dhun Lagi	Media Player-128 Kbps
	Sufi Tere Pyaar Mein - Version II	Media Player-128 Kbps
	Tenu Le	Media Player-128 Kbps
	Dhun Lagi - Remix	Media Player-128 Kbps
	Dhun Lagi - Electro Mix	Media Player-128 Kbps
	Sufi Tere Pyaar Mein - Rock Version	Media Player-128 Kbps
	Tainu Le - Remix	Media Player-128 Kbps

Check the links on the right for new songs from other movies besides Jai Veeru. You can select the links below as well.