10-16-2022 11:11 AM
Hello,
I have a three-router topology with all iBGP sessions in the Established state. A PC (10.1.1.100) is attached to R1's G0/0. The
link between R1 and R2 is also up. Pings from R2 and R3 to 10.1.1.1 (R1 G0/0) are successful but pings from R2 and R3 to the PC are unsuccessful. Any idea why? Thanks in advance.
Solved! Go to Solution.
10-16-2022 11:48 AM
Hi @NBenat ,
It looks like you might be missing a default gateway setting on the PC. It should be set to 10.1.1.1.
Regards,
10-17-2022 03:14 PM
ok instead of ping use traceroute, let see when the ICMP is stop from there we will start troubleshooting.
10-16-2022 11:28 AM - last edited on 10-18-2022 11:27 PM by Translator
first there is split horizon loop prevent in iBGP
so R1 must advertise the prefix into R2 and R3 BUT the
next-hop
is R1,
R3 never advertise the prefix to R2 even if R2-R1 is link is down,
what you need is
run ospf
between the three routers, and then
redistribute BGP into OSPF
this solve your issue.
10-17-2022 03:00 PM
10-17-2022 03:14 PM
ok instead of ping use traceroute, let see when the ICMP is stop from there we will start troubleshooting.
10-17-2022 03:55 PM - last edited on 10-18-2022 11:05 PM by Translator
I did it before but here are the screenshots. They show and thank you for
your suggestions, that R1 is where it stops. That gave me the idea to try a
redistribute connected
on R1 but that didn't help.
10-17-2022 04:07 PM - last edited on 10-18-2022 11:09 PM by Translator
in R1 is stop,
then as @Harold Ritter suggest,
if you emulate router to be as PC then you need
ip defualt-gateway
no ip routing
10-17-2022 04:31 PM
10-17-2022 04:37 PM
usually I use emulate router to be PC,
and this give me some advance like debug and show L2 counter.
anyway
glad your issue is solved.
10-16-2022 11:48 AM
Hi @NBenat ,
It looks like you might be missing a default gateway setting on the PC. It should be set to 10.1.1.1.
Regards,
10-17-2022 02:44 PM
10-17-2022 03:19 PM
Hi @NBenat ,
Since R3 could ping R1 (10.1.1.1), but not the PC (10.1.1.100), it looked like the PC might not have a default gateway. What is the PC? Is it possible that it has a host based FW and that is does not allow the ping from R3?
Regards,
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