BGP problem to expire holdtimer

Mattia Milani mattia.milani at
Thu May 17 12:56:22 CEST 2018

Hello all, i'm writing hear because i have a problem with some simulation
that i'm making, the simulation is on my laptop with VM.
I'm focusing on the hold timer expiration, i want to make this timer expire
and see the differences.

This is my topology:


H1 and H5 are the only one that share some route, i'll call them R1 and R2.

So when the network it will be stabilized, in all RT (H1,H2,H3,H4,H5) I
will have 2 voice, one to reach R1 and one to reach R2.

In every host i setted an hold timer = 3 for every session, with this

hold time 3;

Now i want to "kill" the node H3 and see this result: after 3 seconds see
in the RT of H2 and H4 a variation, like one cannot more reach R1 and the
other one cannot reach R2.

How can i do it? i need to disable something?

because i tried this:

1)using the command: birdc -s socket_H3 down and shutting down the VM
i see that the process that is shutted down, but the other simulation
changed immediatly the RT

so i tried:
2)use only the command birdc -s socket_H3 down and get active the VM
i was thing that there was a checking on the interface if it is active or
But it didn't work, the RT of others changed istantly.

3) so i was thinking that before closing itself bird send a signal to other
bird connected (i didn't search in the code) so i use the command "sudo
kill -9 *pid*" on the pid of the bird relative to H3, but with a big
surprised i see that not only the process associated with H3 is killed but
it will be closed the process of H2 H3 and H4

i'll try to explain it better:

Process list:
100   Bird_H1
101   Bird_H2
102   Bird_H3
103   Bird_H4
104   Bird_H5

i use "sudo kill -9 102"

process list resulting:
100   Bird_H1
104   Bird_H5

The survives is only the process that was sharing some route.

do you have any suggestion to see the expiration of hold timer in act?

Thanks a lot,
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