Numpty question

Paul Civati paul at
Tue Oct 15 12:06:48 BST 2002

Neil Ford <neil at> wrote:

> What I forgot to mention (Doh!) was that I need the box to run the old
> and new Ips simultaneously whilst I get the DNS changes propagated.
> So taking Paul's suggestion I suspect I need to add in
> # ifconfig fxp0 alias0 x.x.x.x netmask y.y.y.y up (old ip address)

I think you need to adjust the ordering slightly, and it's just 'alias',
the alias0, alias1, aliasN is rc.conf magic.

# ifconfig fxp0 x.x.x.x netmask y.y.y.y alias up

> Which should then hopefully mean that the interface will respond to
> both addresses, correct?

Apart from the routing!

Your default route will point back via the original interface.  I
don't think FreeBSD will let you have two default routes (Solaris
will round robin multiple default routes, IIRC).

So you'll have to work out some way of switching the route across,
probably add a more specific host/network route to where you are
logged in from, via the existing interface, and then remove and
add the default route.

When thinking about routing, you always have to remember the path
to the box, and the return path back.


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