07-20-2009 01:39 PM - edited 03-04-2019 05:29 AM
Hi, can someone help me determine what I am missing:
CRA router---GWA---PE2---P---NAP
From GWA I can ping NAP router OK.
From NAP router, I can ping CRA and GWA.
From CRA, ping times out to NAP.
From CRA, I did trace NAP and I see the traffic is dying on CRA interface.
However I still could not determine what is wrong. GWA routing table is complete and perfect. CRA is directly connected to GWA.
Please find attached GWA, CRA and PE2 show run.
(I am reposting this for clarity.)
Solved! Go to Solution.
07-20-2009 11:20 PM
NAP isn't PE2? is it? the redistribute connected only redistributes interfaces connected to the PE2 router, if NAP is a different router like your ascii drawing indicates to me, then it's not connected to PE2.
Tony
07-20-2009 07:00 PM
Hi
Which IP address on NAP router you are trying to ping from CRA and vice versa.
regds
07-20-2009 10:11 PM
Hi, I was pinging NAP= 192.168.1.1
07-20-2009 07:05 PM
News2010a.
PE2 doesn't appear to have redistribution set between ISIS and BGP or BGP and ISIS.
As NAP can only be learnt from ISIS through PE2 I'd reckon that will be the problem.
HTH
Tony
07-20-2009 10:13 PM
Hi Tony Henry, when I did on PE2 the 'redistribute connected', did I not take care of that? I may be wrong though... let me try to redistribute isis into BGP and see if that improves it.
(...)
!
router bgp 1
no synchronization
bgp log-neighbor-changes
redistribute connected
(...)
07-20-2009 11:20 PM
NAP isn't PE2? is it? the redistribute connected only redistributes interfaces connected to the PE2 router, if NAP is a different router like your ascii drawing indicates to me, then it's not connected to PE2.
Tony
07-20-2009 11:22 PM
while I'm at it I wouldn't mind seeing the results from a show IP route for NAP from each router, that will clarify my earlier thoughts.
Tony
07-21-2009 07:15 PM
You are right that "Provider" routers know about NAP via isis. Regarding the issue that I could not ping NAP from CRA, I did a redistribution on GWA:
!
router bgp 65001
redistribute ospf 1
!
and now I can ping NAP from CRA. It makes sense to me. However, now from NAP I can't ping CRA. That is strange. Note that NAP tells me that it knows the route to CRA. If so, do you know why I can't ping it?
PE2#show ip route nap
Routing entry for 192.168.1.1/32
Known via "isis", distance 115, metric 20, type level-2
Redistributing via isis
Last update from 192.168.1.21 on Serial0/0.1, 00:58:46 ago
Routing Descriptor Blocks:
* 192.168.1.21, from 192.168.1.1, via Serial0/0.1
Route metric is 20, traffic share count is 1
PE2#telnet nap
Trying NAP (192.168.1.1)... Open
NAP#ping cra
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 201.1.0.2, timeout is 2 seconds:
.....
Success rate is 0 percent (0/5)
NAP#show ip route cra
Routing entry for 201.1.0.2/32
Known via "bgp 1", distance 200, metric 0
Tag 65001, type internal
Last update from 150.1.0.6 00:04:00 ago
Routing Descriptor Blocks:
* 150.1.0.6, from 192.168.1.5, 00:04:00 ago
Route metric is 0, traffic share count is 1
AS Hops 1
NAP#telnet pe2
Trying PE2 (192.168.1.2)... Open
PE2#telnet cra
Trying CRA (201.1.0.2)... Open
CRA#ping nap
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.1.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 236/343/452 ms
CRA#show ip route nap
% Network not in table
CRA#
07-21-2009 08:21 PM
OK, so I did on PE2:
router bgp 1
redist isis level-1-2
and now I can ping CRA from NAP router. I can also ping NAP router from CRA. Problem solved!!
The only thing I still don't understand is how come from the NAP router, I did 'show ip route CRA' and the routing information was there already even before the isis redistribution. Then I still needed to do a redist from isis into BGP 1 in order to make it work.
Any ideas?
07-21-2009 09:26 PM
News2010a,
Sorry haven't a clue. I can only assume that they may have been caught up in the default routing that you've got set up some how.
I'm glad it works. you could remove the redistribuiton and give us a look at the sho ip routes and trace routes so I can have a go at explaining it to you?
A question that I have is why are you running three seperate routing protocols. is this a lab that you've got somewhere?
Tony
Tony
07-21-2009 10:04 PM
Yes, it is a lab exercise. Once I get access to the lab again tomorrow I should be able to post it. Thank you.
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