Removing IPv6 address causes all IPv6 traffic to stop working

[Frank de Bot (lists)]

On a older server running FreeBSD 10.2 i have a number of jails. For
migration to FreeBSD I'm planning to shutdown the jail, move the data to
the new server and spin up the jail there. IP addresses are alse moved.

When I remove an IPv6 address with the following command 'ifconfig em0
inet6 v6address/48 delete', all IPv6 traffic on the server stops
working. I can reach IPv6 from outside to the server and from the server
to outside, but everything on the server (jail to jail for example)
immediatly stops working. IPv4 works normally
Unfortunately it's not feasible to bing-bang migrate everything,
ignoring ipv6 is not possible because a lot of the jails interact with
each other with ipv6 (some even exclusivly)

What can cause this?


Regards,

Frank de Bot