Hi, I have an OpenBSD5.7 router with IPv6 enabled. I have multiple IPv6 addresses : - em0 : 2a00:6060::1/64 - em1 : 2001:7f8:81::6:983:1/64 - gif0 : 2001:470:11:c8::2/128
IPv6 access is provided by HurricaneElectric tunnel with BGP. When I try to reach 2001:7a8:b5ad::1, 2001:7f8:81::6:983:1 is selected as the source address : PING6(56=40+8+8 bytes) 2001:7f8:81::6:983:1 --> 2001:7a8:b5ad::1 ^C --- 2001:7a8:b5ad::1 ping6 statistics --- 3 packets transmitted, 0 packets received, 100.0% packet loss Even though : # route -n get 2001:7a8:b5ad::1 route to: 2001:7a8:b5ad::1 destination: 2001:7a8:: mask: ffff:ffff:: gateway: 2001:470:11:c8::2 interface: gif0 if address: 2001:470:11:c8::2 priority: 48 (bgp) flags: <UP,GATEWAY,DONE> use mtu expire 138 0 0 Per RFC6724 : Rule 5: Prefer outgoing interface. If SA is assigned to the interface that will be used to send to D and SB is assigned to a different interface, then prefer SA. Similarly, if SB is assigned to the interface that will be used to send to D and SA is assigned to a different interface, then prefer SB. Per se, it is not a big deal but in my case 2001:7f8:81::/48 is an IXP prefix and it is not announced in the DFZ so packets never make it back to the router. The issue is reproduced with OpenBSD5.8. Anything I could try before diving into the source address selection code ? Denis