zone file : subnetted multihomed

[Kevin Darcy]

Walker Simon-SWALKER1 wrote:

> Hi Everyone,
>
> Actually thinking about this a little (whoops).
>
> If the DNS Server served up a list of three IP addressed for the hostname (say it was called router) to a client. The client (resolver) would work out, from the list of three what IP to use as one if the IP would be in the clients subnet due to the client using its netmask from the local interface?
>
> Is that more likely?
>
> Regards,
>
> Si.
>
> > -----Original Message-----
> > From: Walker Simon-SWALKER1
> > Sent: Monday, December 16, 2002 3:25 PM
> > To: bind-users at isc.org
> > Subject: zone file : subnetted multihomed
> > Sensitivity: Confidential
> >
> >
> > Hi Everyone,
> >
> > As this is my first DNS project I wondered if there are any
> > considerations that I must adhere to if I have a multihomed
> > node (3 interfaces infact) and they are subnetted interfaces
> > from the same main network address.
> >
> > That is to say :
> >
> > Original IP 192.168.50.0
> >
> > Say I subnetted this into 4 networks (255.255.255.192) and
> > now the interfaces on the node are like so :
> >
> > 192.168.50.1--<node>--192.168.50.65
> >                 |
> >          192.168.50.130
> >
> > So in an example in O'reilly is says that you can have one
> > hostname associated with a multihomed node. But I wondered
> > how I go about doing this for a subnetted range like the one
> > above? As how will the BIND Server know how to differentiate
> > them for a particular client request?

You could have the server's name resolve to all 3 addresses and then use "sortlist" to direct clients to their "closest" interface. This only works if you can get the same sortlist definitions into *every* nameserver involved though...

                                                                                                                                        - Kevin