IPv6: rtadvd never propagates prefix

From: O. Hartmann <ohartmann_at_walstatt.org>
Date: Sat, 3 Jul 2021 16:23:04 +0200
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Hello,

running a small homebrewn FreeBSD 13-STABLE based router/ipfw applance on an APU2C4. WAN
interface is tun0 (physically attached to igb0, connected with a modem), opened via ppp
(PPPoE).

Situation:

On IPv6 subnets (ULAs, fc50:baff::, fc50:baff:2::, fc50:baff:66::, fc50:baff:100::), isc-dhcpd
serves propper IPv6 addresses to clients attached to the subnet. 

igb1.1000 ipv6: fc50:baff::1
igb1.2 ipv6: fc50:baff:2::1
.
.
.
igb1.100 ipv6: fc50:baff:100::1

On the router itself, rtadvd
is enabled and the appropriate VLAN NICs are passed via /etc/rtadvd.conf (did also via
rc.conf's rtadvd_interfaces"", but without any mitigating effect):

default:
	:prefixlen#64:

igb1.1000:\
	:tc=default:\
	:addr="c50:baff::":
.
.
.
igb1.100:\
	:tc=default:\
	:addr="c50:baff:100::":

There is no special routing service running on the "router". No static routes configured. The
"router" is forwarding between those IPv4 and IPv6 networks as expected.

Problem:

On clients receiving their IPv6 via DHCPv6 the default gateway never shows up as expected when
using 

rtsold em0 (for instance on a notebook wired to a switch)

On each sunbnet (separated by a vlan capable switch) routing via the router works great when
applying the proper gateway, for instance on network ipv6 with prefix igb1.1000 ipv6:
fc50:baff:2::/64 it is fc50:baff:2::1 (the ipv6 of the NIC/VLAN).

What am I missing here? I think this is not a bug, I'm new to IPv6 and routing and probablz my
thinking that rtadvd is propagating the IPv6 of the attached gatewaying NIC as the router IPv6
for the specific prefix seems to be bullshit.

If someone knows some good entry level literature on that subject (IPv6 routing), please share
with me.

Thanks for the patience and help in advance,

oh

	



- -- 
O. Hartmann

Ich widerspreche der Nutzung oder Übermittlung meiner Daten für
Werbezwecke oder für die Markt- oder Meinungsforschung (§ 28 Abs. 4 BDSG).
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Received on Sat Jul 03 2021 - 14:23:04 UTC

Original text of this message