Hi,My configuration file can work normally on the wireguard tunnel, but GRE does not work. Server1 11: home_1_vpn: <POINTOPOINT,NOARP,UP,LOWER_UP> mtu 1280 qdisc noqueue state UNKNOWN group default qlen 1000 link/none inet 5.101.92.125/32 scope global home_1_vpn valid_lft forever preferred_lft forever root@ll-ix:~# ip route get 2602:feda:ab4:5247:5247:5247:5247:5247 2602:feda:ab4:5247:5247:5247:5247:5247 from :: dev frc_ca src 2602:feda:ab2:5247:5247:5247:5247:5247 metric 1024 pre f medium root@ll-ix:~# birdc s p a FRC_CA BIRD 2.0.7 ready. Name Proto Table State Since Info FRC_CA BGP --- start 2021-07-31 Idle BGP state: Idle Neighbor address: 2602:feda:ab4:5247:5247:5247:5247:5247%frc_ca Neighbor AS: 141011 Local AS: 141011 Channel ipv6 State: DOWN Table: master6 Preference: 100 Input filter: (unnamed) Output filter: (unnamed) root@ll-ix:~# birdc s p HOME_1_ARCH BGP --- up 2021-07-31 Established The protocol home_1_arch use the same template as Server 1 and Server 2,but it do Established.The only difference is using Wireguard as tun,I don't think I have a problem with the IP configuration on Server1 and Server2. protocol bgp FRC_CA from tpl_ibgp { source address 2602:feda:ab2:5247:5247:5247:5247:5247; neighbor 2602:feda:ab4:5247:5247:5247:5247:5247 as 141011; } Server2 9: ll_ix@NONE: <POINTOPOINT,NOARP,UP,LOWER_UP> mtu 1476 qdisc noqueue state UNKNOWN group default qlen 1000 link/gre 104.218.61.232 peer 5.189.255.107 inet6 2602:feda:ab4:5247:5247:5247:5247:5247/128 scope global valid_lft forever preferred_lft forever inet6 fe80::200:5efe:68da:3de8/64 scope link valid_lft forever preferred_lft forever root@vpsuser:~# ip route get 2602:feda:ab4:5247:5247:5247:5247:5247 local 2602:feda:ab4:5247:5247:5247:5247:5247 from :: dev lo table local proto kernel src 2602:feda:ab4:5247:5247:524 7:5247:5247 metric 0 pref medium root@vpsuser:~# birdc s p a LL_IX BIRD 2.0.7 ready. Name Proto Table State Since Info LL_IX BGP --- start 02:48:26.395 Idle BGP state: Idle Neighbor address: 2602:feda:ab2:5247:5247:5247:5247:5247 Neighbor AS: 141011 Local AS: 141011 Channel ipv6 State: DOWN Table: master6 Preference: 100 Input filter: (unnamed) Output filter: (unnamed) protocol bgp LL_IX from tpl_ibgp { source address 2602:feda:ab4:5247:5247:5247:5247:5247; neighbor 2602:feda:ab2:5247:5247:5247:5247:5247 as 141011; } Both Server use the same template,As shown below template bgp tpl_ibgp { local as LOCAL_ASN; rr client; direct; ipv6 { next hop self; import filter { if is_bogon_asn() then { print "is bogon asn", net, " for ASN ", bgp_path.last; reject; } if is_bogon_prefix() then { print "is bogon prefix", net, " for ASN ", bgp_path.last; reject; } accept; }; export filter { if bgp_export_all() then accept; reject; }; }; } Please help me,thanks.