Hi Misc,
Long time listener, seldom caller.
My problem statement: I run OpenBSD 5.6-stable on my fw/router. My ISP
(Comcast in the US) provides native IPv6 support for all their customers.
They provide a /128 address for your external WAN interface, along with a
/64 delegation for your internal LAN. I can use ISC's dhclient binary (from
the isc-dhcp-client-4.3 package) along with OpenBSD's rtsold binary to
request an IP and router gateway information respectively on my fw/router.
My problem is, rtsold is only expected/allowed to be used on host
(non-router) nodes.
"rtsold should be used on IPv6 hosts (non-router nodes) only. The
net.inet6.ip6.forwarding sysctl(8) should be set to zero (see also the -F
option below)." from rtsold(8).
First scenario: forwarding is enabled. The result is that rtsold seemingly
to my naive eyes does nothing. No default ipv6 route is added to the
routing table.
*# sysctl net.inet6.ip6.forwarding *
*net.inet6.ip6.forwarding=1*
*# rtsold -f -D -d em0 *
*rtsold: kernel is configured as a router, not a host*
*setting rdomain 0*
*....*
*em0 is ready*
*send RS on em0, whose state is 2*
*received RA from fe80::c639:3aff:fe02:59fa on em0, state is 2*
Second scenario: forwarding is disabled. Rtsold adds the default ipv6 route
to the routing table.
*# sysctl net.inet6.ip6.forwarding=0*
*net.inet6.ip6.forwarding: 1 -> 0*
*# rtsold -f -D -d em0 *
*setting rdomain 0*
*checking if em0 is ready...*
*em0 is ready*
*send RS on em0, whose state is 2*
*received RA from fe80::c639:3aff:fe02:59fa on em0, state is 2*
*# netstat -rn -f inet6 | grep -e default -e DestinationDestination
Gateway Flags Refs Use Mtu
Prio Ifacedefault fe80::c639:3aff:fe02:59fa%em0
UG 0 0 - 56 em0 *
How do I reconcile rtsold's requirement of not running on a router while
still attempting to provide IPv6 connectivity to hosts behind my OpenBSD
fw/router? I've read various FreeBSD/Linux documentation that their OSen
provide functionality for mixing rtsold on the WAN with IPv6 forwarding,
but I would rather stick with OpenBSD on my fw/router as this is what I've
run for many years.
Thanks,
Jeff
