Re: npf and source routing

[Robert Elz <kre%munnari.OZ.AU@localhost>]

    Date:        Mon, 12 Oct 2020 09:32:12 -0400 (EDT)
    From:        Mouse <mouse%Rodents-Montreal.ORG@localhost>
    Message-ID:  <202010121332.JAA28599%Stone.Rodents-Montreal.ORG@localhost>

  | I give it an address only for the sake of being able to point a route
  | destination out it.  How do you arrange to get packets sent out it in
  | your config?  A route pointing to a LL address?

That one.   IPv6 routes almost always use LL addresses.   My srt0 config
(from /etc/ifconfig.srt0) is ...

	create
	inet6 fe80::1%srt0
	up
	!srtconfig srt0 add 2001:3c8:9009:181::2 /64 xennet0 fe80::1
	!srtconfig srt0 add 2001:3c8:9007:1::21  /64 xennet1 fe80::9007:1:1
	!srtconfig srt0 add 0::0 /0 xennet0 fe80::1
	#
	!route -q add -inet6 default fe80::1%srt0

Note that I don't care (nor does anything else) that srt's are nominally
p2p interfaces (that is, I don't bother setting a meaningless destination
address).

  | Hm, that's odd; I'm not seeing a v6 LL address on my srt0,

If you don't assign it one, none will appear.    But you also (on -5)
might be running an if_srt version old enough that v6 didn't work properly
at all.   That was fixed ages ago, but I'm not sure how many ages.

kre