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 Post subject: RIPv1 hop count mysterious behavior on various routers??
PostPosted: Sat Oct 09, 2010 9:48 am 
Hello everyone!!

I am new to GNS3 but I'm slowly learning :)

Here is my problem I just can't figure out:

The lab is connected according to the image below:

Image


The thing is that I can't get valid RIPv1 hop counts on many IOS and routers!

This a very basic RIPv1 setup where:

R1 advertises networks 192.168.1.0 and 192.168.2.0
R2 advertises networks 192.168.2.0, 192.168.3.0 and 192.168.4.0
R3 advertises networks 192.168.4.0 and 192.168.5.0

On this ios images i get a correct hop count meaning that R1 sees network 192.168.5.0 as 2 hops away which is OK:
c2691-adventerprisek9-mz.124-25c
c3620-j1s3-mz.123-18
C3640-Is-Mz_123-6
c3660-i-mz.124-8
c3725-ipvoice-mz.123-14.T7


R1 correct output:

R1#show ip route

Gateway of last resort is not set

R 192.168.4.0/24 [120/1] via 192.168.2.2, 00:00:01, Serial1/0
R 192.168.5.0/24 [120/2] via 192.168.2.2, 00:00:01, Serial1/0
C 192.168.1.0/24 is directly connected, FastEthernet0/0
C 192.168.2.0/24 is directly connected, Serial1/0
R 192.168.3.0/24 [120/1] via 192.168.2.2, 00:00:06, Serial1/0

Now on all of these images I don't get a correct hop count meaning that R1 sees network 192.168.5.0 as 1 hop away which is NOT OK! :
c3620-ik9o3s7-mz.123-23
c3640-ik9s-mz.123-26
c3640-jk9o3s-mz.124-16a
c3640-jk9s-mz.124-16a
c3660-ik9o3s-mz.124-13b
c3725-advipservicesk9-mz.124-17
c3725-adventerprisek9-mz.124-15.T5


R1 incorrect output that shows on every one of those red marked IOS images above:

R1#show ip route

Gateway of last resort is not set

R 192.168.4.0/24 [120/1] via 192.168.2.2, 00:00:16, Serial1/0
R 192.168.5.0/24 [120/1] via 192.168.2.2, 00:00:16, Serial1/0
C 192.168.1.0/24 is directly connected, FastEthernet0/0
C 192.168.2.0/24 is directly connected, Serial1/0
R 192.168.3.0/24 [120/1] via 192.168.2.2, 00:00:16, Serial1/0

As you can see R1 should have seen 192.168.5.0 as 2 hops away but it doesn't...
R1, R2 and R3 are configured the same on all of the images so that's not the problem!

I don't get this mysterious behaviour and I didn't see anybody else complaining about this problem?

Am I doing something wrong or is it a bug in dynamips/dynagen or is it the IOS images?

Can anbody help me solve this mystery??

Cheers guys! ;)




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 Post subject: Re: RIPv1 hop count mysterious behavior on various routers??
PostPosted: Sun Oct 10, 2010 9:58 pm 
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Joined: Fri Mar 05, 2010 11:33 am
Posts: 1403
Location: Australia
This is clearly a bug - I guess the question really is whether it is a bug with the IOS or Dynamips.

I have tested (via GNS3/dynamips)

c3725-adventerprisek9-mz.124-15.T10
c2600-ipbasek9-mz.124-25b

and found no problem, but I don't have any of the offending images you mention to double-check.

I guess it would be nice to double check on physical hardware before reporting to Cisco - my guess is that it is a known Ciso IOS bug, that got fixed (in the case of the 3725) between adventerprisek9-mz.124-15.T5 and adventerprisek9-mz.124-15.T10

Unfortunately I don't have a physical 3725 close at hand (let alone 3 of them) to test on a physical setup. I DO have several 2600s that I could use to test a physical setup, but you haven't found a problem with any of them. I'll check a couple of 2600 version on real routers over the next couple of days and see if anything else turns up.

LATER:
Seems you're not the first to experience this:
https://supportforums.cisco.com/thread/152250?tstart=0
https://learningnetwork.cisco.com/message/7853 - although I don't know on what basis B Hains makes the statement in this post that:
Quote:
It would appear that this is an issue with specific IOS's when using Dynagen/Dynamips/GNS3! Does not appear to be an issue with Packet Tracer or real hardware
- nor do I see any better evidence in the site he refers to:
http://7200emu.hacki.at/viewtopic.php?t=2912 where they seems to get distracted by using version 2 & (totally irrelevantly) no auto-summary.

So to be really sure, we need someone who has REAL hardware to test your offending images.

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@rednectarchris
GNS3 WorkBench-a VMware image of Ubuntu with GNS3 and VPCS installed and a collection of exercises/labs


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 Post subject: Re: RIPv1 hop count mysterious behavior on various routers??
PostPosted: Mon Oct 11, 2010 9:03 am 
Thanks for the reply!

Something is definitely fishy about this whole thing :)

It would be great if somebody could get their hands on some real hardware and make some test!

Hope we'll be hearing from someone soon! :)

Cheers!


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 Post subject: Re: RIPv1 hop count mysterious behavior on various routers??
PostPosted: Tue Oct 12, 2010 10:30 am 
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Joined: Fri Mar 05, 2010 11:33 am
Posts: 1403
Location: Australia
Have you been able to gleen any information from debug ip rip when using the faulty IOS?

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http://rednectar.net
@rednectarchris
GNS3 WorkBench-a VMware image of Ubuntu with GNS3 and VPCS installed and a collection of exercises/labs


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 Post subject: Re: RIPv1 hop count mysterious behavior on various routers??
PostPosted: Tue Oct 12, 2010 11:56 am 
Here are the outputs:

R1:
-----------------------------------------------------------------------------------------------------
*Mar 1 00:00:33.323: RIP: sending v1 update to 255.255.255.255 via Serial1/0 (1 92.168.2.1)
*Mar 1 00:00:33.323: RIP: build update entries
*Mar 1 00:00:33.323: network 192.168.1.0 metric 1
*Mar 1 00:00:33.523: RIP: received v1 update from 192.168.2.2 on Serial1/0
*Mar 1 00:00:33.527: 192.168.3.0 in 1 hops
*Mar 1 00:00:33.527: 192.168.4.0 in 1 hops
*Mar 1 00:00:33.531: 192.168.5.0 in 1 hops
-----------------------------------------------------------------------------------------------------

R2:
-----------------------------------------------------------------------------------------------------
*Mar 1 00:01:59.551: RIP: sending v1 update to 255.255.255.255 via Serial1/1 (192.168.4.2)
*Mar 1 00:01:59.551: RIP: build update entries
*Mar 1 00:01:59.551: network 192.168.1.0 metric 1
*Mar 1 00:01:59.551: network 192.168.2.0 metric 1
*Mar 1 00:01:59.551: network 192.168.3.0 metric 1
*Mar 1 00:01:59.567: RIP: sending v1 update to 255.255.255.255 via Serial1/0 (192.168.2.2)
*Mar 1 00:01:59.567: RIP: build update entries
*Mar 1 00:01:59.571: network 192.168.3.0 metric 1
*Mar 1 00:01:59.571: network 192.168.4.0 metric 1
*Mar 1 00:01:59.571: network 192.168.5.0 metric 1
R2#
*Mar 1 00:02:18.163: RIP: received v1 update from 192.168.4.1 on Serial1/1
*Mar 1 00:02:18.167: 192.168.5.0 in 1 hops
*Mar 1 00:02:18.631: RIP: received v1 update from 192.168.2.1 on Serial1/0
*Mar 1 00:02:18.635: 192.168.1.0 in 1 hops
-----------------------------------------------------------------------------------------------------

R3:
-----------------------------------------------------------------------------------------------------
*Mar 1 00:01:51.751: RIP: sending v1 update to 255.255.255.255 via Serial1/0 (192.168.4.1)
*Mar 1 00:01:51.751: RIP: build update entries
*Mar 1 00:01:51.751: network 192.168.5.0 metric 1
R3#
*Mar 1 00:01:59.303: RIP: received v1 update from 192.168.4.2 on Serial1/0
*Mar 1 00:01:59.307: 192.168.1.0 in 1 hops
*Mar 1 00:01:59.307: 192.168.2.0 in 1 hops
*Mar 1 00:01:59.311: 192.168.3.0 in 1 hops
-----------------------------------------------------------------------------------------------------


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 Post subject: Re: RIPv1 hop count mysterious behavior on various routers??
PostPosted: Mon Feb 21, 2011 4:48 pm 
Hi - I thought I was the only person to have seen this! I have been using Dynamips with a 3660 image and see very similar issues. I haven't as yet been able to determine whether this is a IOS or Dynamips bug. Cgeers Graham


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 Post subject: Re: RIPv1 hop count mysterious behavior on various routers??
PostPosted: Mon Feb 21, 2011 8:56 pm 
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Joined: Fri Mar 05, 2010 11:33 am
Posts: 1403
Location: Australia
Graham - what version of IOS are you using?
ie - output of:
show ver | include IOS



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http://rednectar.net
@rednectarchris
GNS3 WorkBench-a VMware image of Ubuntu with GNS3 and VPCS installed and a collection of exercises/labs


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