how to compare number of routes in routing table before and after making change

[iam_pomme]

I have situation that I will make some configuration change in a part of routing. Due to there are so many routes in routing table so it can't be comfirmed by eyes that all routes come back, it might be possible that I may lose a few routes.

I would like to know is there anyway to check that I still have all routes like before making change. My protocol is EIGRP.

Thank you in advance for advice.

PK.

[Mahesh Gohil]

Hi Iam,

Many people use perl script to compare the output before and after activity.

moreover there are free software available on net to compare two files..like Notepad++ i am using sometime

Regards

mahesh

[jorge.calvo]

Hello,

The easiest way to check if no routes are missing or added after a change is performing the command "show ip route summary" before and after the change.

The number of Networks and Subnets must be the same if no routes have been added or deleted.

Cheers.

[Mahesh Gohil]

Hi,

pspad is free utility available on net and it is more better than notepad++

Hope this helps

Regards

mahesh

[milan.kulik]

Hi,

Notepad is a very basic tool :-)

There are some programs available with more comfortable functions.

Total Commander "Compare by Content", e.g.

WinMerge is told to be a good free tool.

BR,

Milan

[gatlin007]

I agree with Jorge, can't go wrong with 'show ip route summary'

Router# show ip route summary

Route Source    Networks    Subnets     Overhead    Memory (bytes)

connected       0           3           126         360

static          1           2           126         360

igrp 109        747         12          31878       91080

internal        3                                   360

Total           751         17          32130       92160

[milan.kulik]

Hi,

I agree "sh ip route summary" compares the number of routes in routing table before and after the change - and that was required by the original question.

But from a paranoid point of view: You can get the same number of routes after a change, but they can be different!

So a more reliable way how to check the routing is totally the same after a change applied is to compare "sh ip route" outputs before and after the change.

BR,

Milan

[iam_pomme]

Thank you very much for your all answer.

I also come across the same question as Milan said. How do we know that we still have all exact same routes?

Please correct me if I'm wrong, Route sequence depends on timestamp.I understand that uppermost route in routing table is the one comes up recently. So whenever we enter "clear ip route" or reboot router, It can't guarantee that we still have the same route sequence.

I use some free text editor tools to compare "sh ip route". It is not helpful when the route sequence changes, especially on the core that have a few thousand routes.

I think I will manage to write specific script.It is the only idea I have for now.

Please share If any idea else.

Regards,

PK