Dear Quan Zhou, Thanks for your help. Rae Router1 (/etc/bird.conf) log syslog all; router id 192.168.199.12; protocol kernel { # learn; # Learn all alien routes from the kernel persist; # Don't remove routes on bird shutdown scan time 20; # Scan kernel routing table every 20 seconds # import none; # Default is import all export all; # Default is export none # kernel table 5; # Kernel table to synchronize with (default: main) } protocol device { scan time 10; # Scan interfaces every 10 seconds } protocol bgp { import all; export all; local as 76543; neighbor 192.168.199.13 as 87654; } Router1 (birdc show proto all) BIRD 1.4.5 ready. name proto table state since info kernel1 Kernel master up 2018-05-18 Preference: 10 Input filter: ACCEPT Output filter: ACCEPT Routes: 0 imported, 0 exported, 0 preferred Route change stats: received rejected filtered ignored accepted Import updates: 0 0 0 0 0 Import withdraws: 0 0 --- 0 0 Export updates: 0 0 0 --- 0 Export withdraws: 0 --- --- --- 0 device1 Device master up 2018-05-18 Preference: 240 Input filter: ACCEPT Output filter: REJECT Routes: 0 imported, 0 exported, 0 preferred Route change stats: received rejected filtered ignored accepted Import updates: 0 0 0 0 0 Import withdraws: 0 0 --- 0 0 Export updates: 0 0 0 --- 0 Export withdraws: 0 --- --- --- 0 bgp1 BGP master start 2018-05-18 Connect Socket: No route to host Preference: 100 Input filter: ACCEPT Output filter: ACCEPT Routes: 0 imported, 0 exported, 0 preferred Route change stats: received rejected filtered ignored accepted Import updates: 0 0 0 0 0 Import withdraws: 0 0 --- 0 0 Export updates: 0 0 0 --- 0 Export withdraws: 0 --- --- --- 0 BGP state: Connect Neighbor address: 192.168.199.13 Neighbor AS: 87654 Last error: Socket: No route to host Router2 (/etc/bird.conf) log syslog all; router id 192.138.199.13; protocol kernel { # learn; # Learn all alien routes from the kernel persist; # Don't remove routes on bird shutdown scan time 20; # Scan kernel routing table every 20 seconds # import none; # Default is import all export all; # Default is export none # kernel table 5; # Kernel table to synchronize with (default: main) } protocol device { scan time 10; # Scan interfaces every 10 seconds } protocol bgp { import all; export all; local as 87654; neighbor 192.168.199.12 as 76543; Router2 (birdc show proto all) BIRD 1.4.5 ready. name proto table state since info kernel1 Kernel master up 2018-05-18 Preference: 10 Input filter: ACCEPT Output filter: ACCEPT Routes: 0 imported, 0 exported, 0 preferred Route change stats: received rejected filtered ignored accepted Import updates: 0 0 0 0 0 Import withdraws: 0 0 --- 0 0 Export updates: 0 0 0 --- 0 Export withdraws: 0 --- --- --- 0 device1 Device master up 2018-05-18 Preference: 240 Input filter: ACCEPT Output filter: REJECT Routes: 0 imported, 0 exported, 0 preferred Route change stats: received rejected filtered ignored accepted Import updates: 0 0 0 0 0 Import withdraws: 0 0 --- 0 0 Export updates: 0 0 0 --- 0 Export withdraws: 0 --- --- --- 0 bgp1 BGP master start 2018-05-18 Active Socket: No route to host Preference: 100 Input filter: ACCEPT Output filter: ACCEPT Routes: 0 imported, 0 exported, 0 preferred Route change stats: received rejected filtered ignored accepted Import updates: 0 0 0 0 0 Import withdraws: 0 0 --- 0 0 Export updates: 0 0 0 --- 0 Export withdraws: 0 --- --- --- 0 BGP state: Active Neighbor address: 192.168.199.12 Neighbor AS: 76543 Start delay: 0/5 Last error: Socket: No route to host From: Bird-users <bird-users-bounces@network.cz> On Behalf Of Quan Zhou Sent: Monday, June 4, 2018 6:01 PM Cc: bird-users@network.cz Subject: Re: BIRD router/route server functions It'd be more helpful you can provide your `bird.conf` and `birdc show proto all` if all possible. On Mon, Jun 4, 2018 at 4:54 PM Rae Ho (ITSC) <raeho@cuhk.edu.hk<mailto:raeho@cuhk.edu.hk>> wrote: Dear MO, Thank you very much for your response. Yes, I followed the sample to set up the routers but don’t why the peering session between them is not established. Rae From: mo@linx.net<mailto:mo@linx.net> <mo@linx.net<mailto:mo@linx.net>> Sent: Monday, June 4, 2018 4:40 PM To: Rae Ho (ITSC) <raeho@cuhk.edu.hk<mailto:raeho@cuhk.edu.hk>> Cc: bird-users@network.cz<mailto:bird-users@network.cz> Subject: Re: BIRD router/route server functions On 4 Jun 2018, at 07:08, Rae Ho (ITSC) <raeho@cuhk.edu.hk<mailto:raeho@cuhk.edu.hk>> wrote: Dear All, I’m Rae of CUHK. We are exploring BIRD router/route server functions. Now I set up 2 BIRD routers to from BGP session between them, seems It can’t form the peering (in active status). Questions: 1. Is there any pre-config need to be set up? (i.e. interface? Internal Subnet?) 2. Would you mind sending me some sample configurations? Rae Try looking here. https://gitlab.labs.nic.cz/labs/bird/wikis/Examples Mo