Have you looked into the logs? There should be written why these processes are also down. Or you should somewhere collect their status to see whether they ended correctly or failed somehow.
Maria
yeah, i had looked into the logs but I diddn't see anything strange, here is the last part of the logs, i'm using the command "log filetolog.log all;" Log of H3, the one that i killed with kill -9: 2018-05-17 14:03:50.710 <TRACE> h3_3_h4_4: Got KEEPALIVE 2018-05-17 14:03:50.972 <TRACE> h3_3_h2_2: Sending KEEPALIVE 2018-05-17 14:03:51.178 <TRACE> h3_3_h2_2: Got KEEPALIVE 2018-05-17 14:03:51.517 <TRACE> h3_3_h4_4: Sending KEEPALIVE 2018-05-17 14:03:51.533 <TRACE> device1: Scanning interfaces 2018-05-17 14:03:51.534 <TRACE> h3_3_h4_4: Got KEEPALIVE -----here the log is brusquely interruptet by the kill ------- here is the log of H2 (with htop i see that the process is interruptet with the process of H3): 2018-05-17 14:03:51.290 <TRACE> h2_2_h1_1: Got KEEPALIVE 2018-05-17 14:03:51.535 <TRACE> device1: Scanning interfaces 2018-05-17 14:03:51.608 <TRACE> h2_2_h3_3: Connection closed 2018-05-17 14:03:51.608 <TRACE> h2_2_h3_3: BGP session closed 2018-05-17 14:03:51.608 <TRACE> h2_2_h3_3: State changed to stop 2018-05-17 14:03:51.608 <TRACE> h2_2_h3_3 > removed [sole] 100.1.2.0/24 unicast 2018-05-17 14:03:51.608 <TRACE> kernel1 < removed 100.1.2.0/24 unicast 2018-05-17 14:03:51.608 <TRACE> h2_2_h1_1 < removed 100.1.2.0/24 unicast here the log of H4: 2018-05-17 14:14:53.662 <TRACE> device1: Scanning interfaces 2018-05-17 14:14:53.732 <TRACE> h4_4_h3_3: Connection closed 2018-05-17 14:14:53.732 <TRACE> h4_4_h3_3: BGP session closed 2018-05-17 14:14:53.732 <TRACE> h4_4_h3_3: State changed to stop 2018-05-17 14:14:53.733 <TRACE> h4_4_h3_3 > removed [sole] 100.1.1.0/24 unicast 2018-05-17 14:14:53.733 <TRACE> kernel1 < removed 100.1.1.0/24 unicast 2018-05-17 14:14:53.733 <TRACE> h4_4_h5_5 < removed 100.1.1.0/24 unicast all the log is brusquely interruptet, and i don't know why. and after this...do you know if there is in bird some check in the interface if it is already on? so if i disable the interface beetween the host could i reach the result that i want? thanks, Mattia