Bug 233683 - IPv6 ND neighbor solicitation messages fail to arrive
Summary: IPv6 ND neighbor solicitation messages fail to arrive
Status: New
Alias: None
Product: Base System
Classification: Unclassified
Component: kern (show other bugs)
Version: 12.0-RELEASE
Hardware: amd64 Any
: --- Affects Only Me
Assignee: freebsd-net (Nobody)
Depends on:
Reported: 2018-12-01 11:38 UTC by Philip Homburg
Modified: 2018-12-02 09:41 UTC (History)
1 user (show)

See Also:


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Description Philip Homburg 2018-12-01 11:38:26 UTC
On 12.0-RC2 (and earlier) after a while, IPv6 ND neighbor solicitation messages fail to arrive. I guess it is a bug in multicast filtering. But I have no way to find out.

Result is loss of IPv6 connectivity.
Comment 1 Bjoern A. Zeeb freebsd_committer 2018-12-01 18:37:11 UTC
How do you determine they fail to arrive?

Do you have a trace from other hosts?  No filters in the network?

In these cases, which NIC/driver are you using?  What happens if you turn on PROMISC/MONITOR mode on the interface?
Comment 2 Philip Homburg 2018-12-01 18:46:43 UTC
I have a setup with a tp-link running openwrt as router, as small switch behind the wired ethernet ports of the tp-link and then a few freebsd hosts.

One recently built ryzen2 system has an re0 interface. This system works perfectly fine under 11.2 and fails under 12.0 betas and RC1/RC2. With boot environments I can easily switch between the two versions.

When I reported this bug, I just upgraded a Thinkpad x201 (em0 interface) to RC2.
The thinkpad didn't report any neighbor solicitations even with tcpdump. At the same time, on the tplink they were visible in tcpdump.

Also a ping6 from the ryzen2 system (running 11.2) to the thinkpad failed.