Since we are sleeping for an indefinite period of time waiting
for the default route to appear, the expire times may be gone
past 1+ seconds, causing the Expire column to show <1800 or <600.

Fixes:	f6bcc0925f0ea838da5183dc503f847e56d15cc8

Reviewed by:	pouria
Approved by:	lwhsu (mentor)
MFC after:	3 days
Differential Revision:	https://reviews.freebsd.org/D56712

Per [siva@'s comment on the PR][1], this testcase now passes cleanly in CI.

PR:	274941
MFC after:	1 week

[1]: https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=274941#c6

This reverts commit 86e87c3bd1b377242aafe7e2222ae17ca0be96d9.

Approved by:	pouria
Sponsored by:	Netflix
Differential Revision:	https://reviews.freebsd.org/D56569

Test handling of receiving multiple route information options in RA.

Reviewed by: glebius
Differential Revision: https://reviews.freebsd.org/D56216

* RA hop limit validation
* RA source address validation
* Multi router RA validation
* Two hour rule RA validation
* SLAAC onlink prefix switching test

Reviewed by: glebius
Differential Revision: https://reviews.freebsd.org/D56128

These use atf_python to create a number of hosts linked to a router.
The router runs pimd (for IPv4) or ip6_mrouter (simplistic IPv6
multicast router that I wrote since I couldn't find one in the ports
tree).  The vnet_host*_handler() methods are invoked in different VNET
jails connected to the router; they register the connected epair with a
multicast group and verify that they can send messages to each other.

The tests are synchronized by sending messages over a unix domain
socket.  The flow is something like:
1) test startup_method() is called, the unix socket is created,
2) the superclass creates jails and links them together using the
   declared topology,
3) we wait for all child jails to start up and send a message on the
   unix socket indicating that they are ready
4) we start the routing daemon in the main jail,
5) the test actually starts; starttest() kicks off the
   vnet_host*_handlers(), which mostly just verify that they can send
   messages to each other using multicast packets
6) once they finish running, they signal their completion, and
   waittest() returns once they're all done

There are two tests, repeated for v4 and v6.  One just exchanges packets
between two hosts, and the other has four hosts divided across two FIBs.

MFC after:	2 weeks
Sponsored by:	Stormshield
Sponsored by:	Klara, Inc.
Differential Revision:	https://reviews.freebsd.org/D55244

The ROUTE_MPATH compile option was introduced to
test the new multipath implementation.
Since compiling it has no overhead and it's enabled
by default, remove it.

Reviewed by:	melifaro, markj
Relnotes:	yes
Differential Revision: https://reviews.freebsd.org/D55884

Add test for ndp to verity link-layer address change event
actually triggers the grand.

Differential Revision: https://reviews.freebsd.org/D55927

The test sends RAs in order to test SLAAC handling in another host.
The router needs to also set net.inet6.ip6.forwarding=1, otherwise NAs
sent from it have the ROUTER flag clear, and upon receiving such an NA
the host will automatically delete routes learned from the router.

Fixes:		feda329622bc ("netinet6 tests: Add a regression test for default router handling")
MFC after:	1 week
Sponsored by:	Klara, Inc.

Here we have two interface addresses sharing a v6 prefix with finite
lifetime.  The intent was to make sure that adding the second address
didn't cause the prefix's valid lifetime to drop from 20s to 10s, but of
course, while the test is running it may drop from 20s to 19s, causing
the test to fail spuriously.  Relax the check a bit to avoid this.

PR:		293152
Fixes:		74999aac5eff ("in6: Modify address prefix lifetimes when updating address lifetimes")
MFC after:	1 week
Sponsored by:	Klara, Inc.