[afnog] change router ip remotely

[Randy Bush]

> first thought:
> - copy running-config tftp
> - vi on tftp-server
> - copy tftp startup-config
> - cross fingers
> - reload

i have done that many times.  it works if i have made no errors.  and,
of course, i never make errors.  and pigs fly.

> second thought and I like it much better.
> - ssh -6 xxxx:xxxx:xxxx::xxxx     (log into router using ipv6)
>   (that works already! from same network segment)
> - remove all ipv4 addresses and put new ones

never tried that.  could work.  but if the v6 connectivity relies on v4
tunneling or v4 bgp peerings, ...

randy