Solved vnet MAC address when using jails - how to avoid leaking?

zirias@ · Jun 5, 2023

codetrotter, no. In general, longer prefixes still work fine, just tried that on a box running 13.2:

Code:

# ifconfig tap0 create
# ifconfig tap0 inet6 2001:xxxx:xxxx:xxxx:xxxx::1 prefixlen 80
# ifconfig tap0
tap0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
        options=80000<LINKSTATE>
        ether 58:9c:fc:10:c9:7b
        inet6 2001:xxxx:xxxx:xxxx:xxxx::1 prefixlen 80
        inet6 fe80::5a9c:fcff:fe10:c97b%tap0 prefixlen 64 scopeid 0x3
        groups: tap
        media: Ethernet autoselect
        status: no carrier
        nd6 options=23<PERFORMNUD,ACCEPT_RTADV,AUTO_LINKLOCAL>

So, look for and analyze logs ... and try to setup the interface manually with ifconfig and friends and see what exactly goes wrong ....

codetrotter · Jun 5, 2023

Thanks for having a look zirias@

My initial investigations in the weekend did not show any enlightening log entries in /var/log/messages

Nor was I yet able to figure out anything useful from manually running ifconfig in the jails

I'll continue to look into this further when I have more time

codetrotter · Jun 10, 2023

Aight so I've been investigating a bit more.

In the end I am still not sure why exactly it stopped working when I upgraded to 13.2-RELEASE.

But I did get it working again.

So what I did mainly was to further change the prefixlen as I was suspecting that prefixlen 80 was causing confusion for FreeBSD about where to route things because I had multiple interfaces in the same IPv6 /80

So now I have separate /96 prefixes for different jails

And I keep my external interface at /80 still

And now I have something that appears to be working again, running on 13.2-RELEASE