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Self ping serial interface

saimbt
Level 1
Level 1

Hi,

If we have 2 routers,

rtrA serial IP address 1.1.1.1

rtrB serial IP address 1.1.1.2

both the serial ports are connected through a leased line.

If i ping 1.1.1.1 from rtrA the delay is around 36ms, and if i ping 1.1.1.2 from rtrA the delay is around 18 ms,

i guess if i do a self ping on the serial interface, it goes till the next ip address and returns back.

also if the serial link is down, the self serial ip address is not able to ping itself.

kindly explain the logic behind it.

Sai.

31 Replies 31

Well, if the question is general about statics

(e.g. What is the default AD of static routes ?), I would say 1.

If it says "via next-hop", then it's also 1.

If it says "via local interface", you are unlucky.

These authors seem to me as if they are proud they "found this out",

because they haven't ever wondered if they are actually right about it,

and because they really like this question.

The formal syntax of the "ip route" command is :

ip route prefix mask {ip-address | interface-type interface-number [ip-address]}

[distance] [name][permanent | track number] [tag tag]

I am curious what the "genius" test engine would say about the AD of statics

which specify BOTH a local interface AND a next-hop.

Is this 0.5 ? :-)

I'd rather face a real router that literally crashes from time to time,

than face a "genius" test engine that metaphorically crashes all the time.

Kevin, I think you should stop worrying about The Lab.

I believe there are real router-babies there.

Good luck on your CCIE, and if you decide to write a book after you achieve CCIE status,

please allow us to send our corrections :-)))

Writing a book is not an easy job, even if you have managed

to kill the "Big Evil CCIE Dragon" and have many years of experience.

The Learning Game is never over.

M.

It works over ATM interfaces/subinterfaces as well.

This is handy to check for loops in the carrier network, and checking for errors in the WAN by setting a software loop on one end or the other. I've solved several issues using these plus a "debug ip icmp"

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