network outages

Hi!

After updating to today's -current, I have very spotty
connectivity. After about an hour of uptime, network traffic just
stopped - ssh from outside doesn't work, mtr/traceroute from inside
doesn't work, not a single hop.

dmesg is not helpful, it just lists NFS share problems.

nfs server XXX.XXX.XXX.XXX:/path: not responding

every couple minutes.

In /var/log/messages I see:

Mar 20 17:31:46 exadelic dhcpcd[2990]: igc0: fe80::xxx is unreachable
Mar 20 17:31:57 exadelic dhcpcd[2990]: igc0: fe80::xxx is reachable again

ifconfig igc0 down/up made it work again, but the second lossage was
just ten minutes later.

Anyone else seeing similar problems?
Any ideas?

It started happening very soon after new kernel + userland from
20260320 (previous one was from 20260301), so there's a good chance
it's a software problem.
 Thomas