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Ping

Pls. help, im just a novice in networking. I just want to know what is the difference between normal ping and extended ping in a router. I tried to ping the neighbor router using normal ping but its unsuccessful. I used extended ping target:neighbor router S0 source: E0 from other router and its successful, why is it so? thanks in advance.

5 REPLIES

Re: Ping

standard ping doesnt allow ping packets options to be tweaked. extended ping allows you to change source address, specify data pattern in ping packet, set TOS bits ,specify timeouts, specify packet lengths, specify number of ping packets etc and many more.

What kind of connection exists between the routers in question.

New Member

Re: Ping

thanks, but what i want to know is that how come i was not able to ping the neighbor router's port using normal ping but when i use extended ping its successfull.

New Member

Re: Ping

The answer to your question is answered by Shankar already in the previous post... it is quite possible that you are specifying a different Source address in Extended ping... then the one in Normal ping...

Hope you find this helpful....

~sultan

Hall of Fame Super Silver

Re: Ping

Oliver really posed two questions in the original post: he wanted to know about the differences between standard ping and extended ping, and he wanted to know why standard ping failed but extended ping succeeded. Sankar's answer was a good answer to the first question and an indirect answer to the second question.

To really be able to answer the question about why standard ping failed but extended ping succeeded we will need to know some additional information about the routers. But we can guess at the answer based on the symptoms. Based on the fact that standard ping failed but extended ping which specified the source address succeeded I would guess that the remote router has a route to the interface specified in extended ping (I believe the Ethernet interface) but does not have a route to the interface used by standard ping.

If we want to proove that this is the explanation we will need the following outputs:

- show ip interface brief from both routers

- show ip route from both routers.

if we have this we can determine which interface would be used by standard ping and can determine whether that subnet is in the routing table of the other router.

The explanation for this is that by default standard ping will use the IP address of the outbound interface as the source address of the ping packet. If the ping packet gets to the remote router but the remote router does not have that subnet in its routing table then it can not respond and the ping will fail. When using extended ping we have the ability to specify the source address. And if we specify a source address and its subnet is in the routing table then extended ping will succeed.

HTH

Rick

New Member

Re: Ping

Thanks a lot Rick, your answer gave me a clear understanding of my questions, on what are the possible causes why I cannot ping using standard but not with extended ping. I will try to post the show ip int br output and show ip route output to really have a clear analysis of my problem.

Thanks a lot! also to Shanky, appreciate it mate!

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