Hi,
I'm experiencing a problem with my NetBSD AWS EC2
instance flapping the default IPv6 route:
The system is an amd64 EC2 instance using:
# uname -a
NetBSD netbsd 9.99.78 NetBSD 9.99.78 (GENERIC) #0: Fri Jan 22 00:44:55 UTC 2021
mkre...@mkrepro.netbsd.org:/usr/src/sys/arch/amd64/compile/GENERIC amd64
I have 'dhcpcd=YES' and the system comes up with an
IPv6 lease:
# ifconfig xennet0
xennet0: flags=0x8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
capabilities=0x17c00<TCP4CSUM_Rx,TCP4CSUM_Tx,UDP4CSUM_Rx,UDP4CSUM_Tx>
capabilities=0x17c00<TCP6CSUM_Rx,UDP6CSUM_Rx>
enabled=0
ec_capabilities=0x5<VLAN_MTU,JUMBO_MTU>
ec_enabled=0
address: 0e:61:d2:b8:e6:b1
inet 10.10.0.47/26 broadcast 10.10.0.63 flags 0
inet6 fe80::7e12:b688:167c:785f%xennet0/64 flags 0 scopeid 0x1
inet6 2600:1f18:400c:b800:bc3c:63cc:7e5d:1f96/128 flags 0
# route get -inet6 default
route to: ::
destination: ::
mask: default
gateway: fe80::caa:49ff:feaf:1815%xennet0
local addr: fe80::7e12:b688:167c:785f%xennet0
interface: xennet0
flags: 0x43<UP,GATEWAY,DONE>
recvpipe sendpipe ssthresh rtt,msec rttvar hopcount mtu expire
0 0 0 0 0 0 0 0
Everything's working fine, but just about every 10
seconds or so, the default IPv6 route drops, it
solicits a default route, and then immediately gets
the same RA:
Apr 20 01:32:32 netbsd dhcpcd[17397]: xennet0: soliciting an IPv6 router
Apr 20 01:32:34 netbsd dhcpcd[17397]: xennet0: Router Advertisement from
fe80::caa:49ff:feaf:1815
Apr 20 01:32:35 netbsd dhcpcd[17397]: xennet0: fe80::caa:49ff:feaf:1815 is
unreachable
Apr 20 01:32:35 netbsd dhcpcd[17397]: xennet0: soliciting an IPv6 router
Apr 20 01:32:44 netbsd dhcpcd[17397]: xennet0: fe80::caa:49ff:feaf:1815 is
reachable again
Apr 20 01:32:52 netbsd dhcpcd[17397]: xennet0: fe80::caa:49ff:feaf:1815 is
unreachable
Apr 20 01:32:52 netbsd dhcpcd[17397]: xennet0: soliciting an IPv6 router
Apr 20 01:32:54 netbsd dhcpcd[17397]: xennet0: Router Advertisement from
fe80::caa:49ff:feaf:1815
Apr 20 01:32:55 netbsd dhcpcd[17397]: xennet0: fe80::caa:49ff:feaf:1815 is
unreachable
Apr 20 01:32:56 netbsd dhcpcd[17397]: xennet0: soliciting an IPv6 router
Note: other OS instances on the same VPC (i.e.,
getting the same network information and using the
same default route) do not see this problem -- it only
appears on NetBSD.
Does anybody know what might be causing this?
-Jan
