IPv4 *and* IPv6 addresses for home_servers and failover

[Bob Franklin]

Hello,

I'd just just to check FreeRADIUS operates as I'm expecting (and have 
observed, in the limited amount of testing I've been able to do, before 
plugging things into the real world).  I'm trying to get our FreeRADIUS 
2.1.12 servers ready to handle IPv4 and IPv6 and, in particular, 
IPv6-accessible home_servers (e.g. the UK JANET Roaming NRPS ones).


If I do:

   home_server ja-net-roaming0_server {

... I have to put ONE of:

     ipaddr = roaming0.ja.net
     ipv6addr = roaming0.ja.net

... which one I put will control whether IPv4 or IPv6 is used to contact 
that host.

If so, does this mean that, if I want to allow the possibility of talking 
to the servers over IPv6 as well as IPv4 (and failing between one and 
other, if either are unavailable), I have to configure two distinct 
servers and set them up in the pool?  e.g.

   home_server ja-net-roaming0_server {
     ipaddr = roaming0.ja.net     [or the IPv4 address]
     ...
   }

   home_server ja-net-roaming0_server6 {
     ipv6addr = roaming0.ja.net   [or the IPv6 address]
     ...
   }

   ...

   server_pool ja-net_pool {
     type = client-balance
     home_server = ja-net-roaming0_server
     home_server = ja-net-roaming0_server6
     home_server = ja-net-roaming1_server
     home_server = ja-net-roaming1_server6
     ...
   }

This will mean that, when everything in the pool is up, some clients will 
always get an IPv4 home_server and some an IPv6 one.


I just want to confirm there's no way to configure a single home server 
that can use both IPv4 and IPv6, or have ones that use IPv6 unless it's 
available, then fail back to IPv4, and that what I'm proposing above is 
the recommended way of doing this.


[I realise that, if I configure them separately like this, I have to 
manually manage whether individual home servers have IPv4 or IPv6 
registrations.]

Thanks for your help,

   - Bob


-- 
  Bob Franklin <rcf34 at cam.ac.uk>              +44 1223 748479
  Network Division, University of Cambridge Computing Service