[Bug 248005] nd6 initializes nd_ifinfo->maxmtu = 0 on newly inserted network interfaces

[b***@freebsd.org]

https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=248005

Andrey V. Elsukov <***@FreeBSD.org> changed:

What |Removed |Added
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CC| |***@FreeBSD.org

--- Comment #5 from Andrey V. Elsukov <***@FreeBSD.org> ---
After this patch IPv6 link prefix routes on vlan(4) interfaces have 1500 MTU
instead of MTU configured on vlan, i.e. after upgrade all IPv6 link prefix
routes have 1500 MTU instead of 9000.

[b***@freebsd.org]

https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=248005

--- Comment #6 from Andrey V. Elsukov <***@FreeBSD.org> ---
How it worked before patch:
# ifconfig vlan1000 create vlandev mce3 vlan 1000 up
# ifconfig vlan1000
vlan1000: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 9000

options=1c680003<RXCSUM,TXCSUM,LINKSTATE,RXCSUM_IPV6,TXCSUM_IPV6,NOMAP,TXTLS4,TXTLS6>
ether 24:8a:07:b4:32:43
inet6 fe80::268a:7ff:feb4:3243%vlan1000 prefixlen 64 scopeid 0x8
groups: vlan
vlan: 1000 vlanpcp: 0 parent interface: mce3
media: Ethernet autoselect <full-duplex,rxpause,txpause> (100GBase-CR4
<full-duplex,rxpause,txpause>)
status: active
nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL>
# netstat -Wrnf inet6 | grep vlan1000
fe80::%vlan1000/64 link#8 U 11
9000 vlan1000
fe80::268a:7ff:feb4:3243%vlan1000 link#3 UHS 1
16384 lo0
# ndp -i vlan1000
linkmtu=0, maxmtu=0, curhlim=64, basereachable=30s0ms, reachable=27s,
retrans=1s0ms
Flags: nud auto_linklocal

After this patch:
# netstat -Wrnf inet6 | grep vlan1000
fe80::%vlan1000/64 link#8 U 11
1500 vlan1000
fe80::268a:7ff:feb4:3243%vlan1000 link#3 UHS 1
16384 lo0
# ndp -i vlan1000
linkmtu=0, maxmtu=1500, curhlim=64, basereachable=30s0ms, reachable=18s,
retrans=1s0ms
Flags: nud auto_linklocal

[b***@freebsd.org]

https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=248005

Andrey V. Elsukov <***@FreeBSD.org> changed:

What |Removed |Added
----------------------------------------------------------------------------
See Also| |https://bugs.freebsd.org/bu
| |gzilla/show_bug.cgi?id=2557
| |49