Hello,
I have an OpenBSD router with a few interfaces, connected to a few
other routers, sharing routes with ospf(6)d.
There's also some hosts connected to its interfaces.
rtadvd.conf is really simple:
# cat /etc/rtadvd.conf
em0:\
:rdnss="2001:6f8:3c8:42::10":\
:dnssl="geekwu.org":
em1:\
:rdnss="2001:6f8:3c8:42::10":\
:dnssl="geekwu.org":
em5:\
:rdnss="2001:6f8:3c8:42::10":\
:dnssl="geekwu.org":
em4:\
:rdnss="2001:6f8:3c8:42::10":\
:dnssl="geekwu.org":
A router connected to em1 provides connectivity to the prefix
2001:41d0:fe4b:ec01::/64 ; so whe have this in OSPF6 RIB:
Destination Nexthop Path Type Type Cost Uptime
2001:41d0:fe4b:ec01::/64 fe80::225:22ff:fe1e:bb7%em1 Type 1 ext Network 10
00:26:13
and this in routing table :
Destination Gateway Flags Refs
Use Mtu Prio Iface
2001:41d0:fe4b:ec01::/64 fe80::225:22ff:fe1e:bb7%em1 UG 0
0 - 32 em1
em1 have 2 inet6 address configured :
em1: flags=18843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST,MPSAFE> mtu 1500
lladdr 00:00:24:d1:42:0d
description: DMZ
[...]
inet6 fe80::200:24ff:fed1:420d%em1 prefixlen 64 scopeid 0x2
inet6 2001:6f8:3c8:42:200:24ff:fec6:94c8 prefixlen 64
inet6 2001:41d0:fe4b:ec42:200:24ff:fed1:420d prefixlen 64
And the router sends RAs on this interface with *3* prefixes :
15:23:54.878534 IP6 (hlim 255, next-header ICMPv6 (58) payload length: 168)
fe80::200:24ff:fed1:420d > ff02::1: [icmp6 sum ok] ICMP6, router advertisement,
length 168
hop limit 64, Flags [none], pref medium, router lifetime 1800s,
reachable time 0s, retrans time 0s
source link-address option (1), length 8 (1): 00:00:24:d1:42:0d
0x0000: 0000 24d1 420d
prefix info option (3), length 32 (4): 2001:6f8:3c8:42::/64, Flags
[onlink, auto], valid time 2592000s, pref. time 604800s
0x0000: 40c0 0027 8d00 0009 3a80 0000 0000 2001
0x0010: 06f8 03c8 0042 0000 0000 0000 0000
prefix info option (3), length 32 (4): 2001:41d0:fe4b:ec42::/64,
Flags [onlink, auto], valid time 2592000s, pref. time 604800s
0x0000: 40c0 0027 8d00 0009 3a80 0000 0000 2001
0x0010: 41d0 fe4b ec42 0000 0000 0000 0000
prefix info option (3), length 32 (4): 2001:41d0:fe4b:ec01::/64,
Flags [onlink, auto], valid time 2592000s, pref. time 604800s
0x0000: 40c0 0027 8d00 0009 3a80 0000 0000 2001
0x0010: 41d0 fe4b ec01 0000 0000 0000 0000
rdnss option (25), length 24 (3): lifetime 900s, addr:
2001:6f8:3c8:42::10
0x0000: 0000 0000 0384 2001 06f8 03c8 0042 0000
0x0010: 0000 0000 0010
dnssl option (31), length 24 (3): lifetime 900s, domain(s):
geekwu.org.
0x0000: 0000 0000 0384 0667 6565 6b77 7503 6f72
0x0010: 6700 0000 0000
If I disconnect the 2001:41d0:fe4b:ec01::/64 from the remote router, it
disappear from OSPF6 RIB, and from RAs too.
15:33:59.901622 IP6 (hlim 255, next-header ICMPv6 (58) payload length: 136)
fe80::200:24ff:fed1:420d > ff02::1: [icmp6 sum ok] ICMP6, router advertisement,
length 136
hop limit 64, Flags [none], pref medium, router lifetime 1800s,
reachable time 0s, retrans time 0s
source link-address option (1), length 8 (1): 00:00:24:d1:42:0d
0x0000: 0000 24d1 420d
prefix info option (3), length 32 (4): 2001:6f8:3c8:42::/64, Flags
[onlink, auto], valid time 2592000s, pref. time 604800s
0x0000: 40c0 0027 8d00 0009 3a80 0000 0000 2001
0x0010: 06f8 03c8 0042 0000 0000 0000 0000
prefix info option (3), length 32 (4): 2001:41d0:fe4b:ec42::/64,
Flags [onlink, auto], valid time 2592000s, pref. time 604800s
0x0000: 40c0 0027 8d00 0009 3a80 0000 0000 2001
0x0010: 41d0 fe4b ec42 0000 0000 0000 0000
rdnss option (25), length 24 (3): lifetime 900s, addr:
2001:6f8:3c8:42::10
0x0000: 0000 0000 0384 2001 06f8 03c8 0042 0000
0x0010: 0000 0000 0010
dnssl option (31), length 24 (3): lifetime 900s, domain(s):
geekwu.org.
0x0000: 0000 0000 0384 0667 6565 6b77 7503 6f72
0x0010: 6700 0000 0000
The prefix is only advertised on em1, not on the other interfaces.
Is there a way to prevent rtadvd from advertising
2001:41d0:fe4b:ec01::/64 ?
Thanks,
--
Bastien
