BGP problem to expire holdtimer

[Maria Jan Matějka]

On May 17, 2018 4:31:18 PM GMT+02:00, Mattia Milani <mattia.milani at studenti.unitn.it> wrote:
>making ifconfig eth* down in the interface of H3, on H2 and H4 it
>relevated
>this in the log:
>
>2018-05-17 16:26:38.462 <TRACE> kernel1 < interface h1_1-eth2 changes
>link
>2018-05-17 16:26:38.462 <TRACE> direct1 < interface h1_1-eth2 changes
>link
>2018-05-17 16:26:38.462 <TRACE> h2_2_h3_3: Link down
>2018-05-17 16:26:38.462 <TRACE> h2_2_h3_3: State changed to stop
>2018-05-17 16:26:38.462 <TRACE> h2_2_h3_3: BGP session closed
>2018-05-17 16:26:38.462 <TRACE> h2_2_h3_3 > removed [sole] 100.1.2.0/24
>unicast
>2018-05-17 16:26:38.462 <TRACE> kernel1 < removed 100.1.2.0/24 unicast
>2018-05-17 16:26:38.462 <TRACE> h2_2_h1_1 < removed 100.1.2.0/24
>unicast
>2018-05-17 16:26:38.462 <TRACE> h2_2_h3_3: Sending
>NOTIFICATION(code=6.0)
>2018-05-17 16:26:38.463 <TRACE> h2_2_h1_1: Sending UPDATE
>2018-05-17 16:26:38.463 <TRACE> h2_2_h3_3: Down
>
>it learn istantly that the link now is down, how can i do this without
>losing the link?

The same way as making any other tcp session disconnect immediately. You may try iptables or dropping the link in your virtual hypervisor or whatever else is applicable to your config. 

Maria