SLUG Mailing List Archives
RE: [SLUG] mail service outages
- To: slug@xxxxxxxxxxx
- Subject: RE: [SLUG] mail service outages
- From: John Wiltshire <jw@xxxxxxxxxxx>
- Date: Thu Aug 10 11:33:03 2000
From: marty [mailto:marty@xxxxxxxxxx]
>sorry if this is a dumb question:
>can you have multiple routes to a single IP ??
>surely at some point you have to have a SPF...
Not a dumb question at all.
You can define multiple routes to a network. For example, you may have a
connection via OzEmail and Access One and define routes through both
providers. BGP will advertise them both and external clients will choose
their best route (or possibly load balance between them).
Ok, so now you have redundant routes to your network. The network can exist
in multiple physical locations connected by a VLAN link to make it appear
all on the one subnet. Each of your ISP routes would go to the different
Now you have one network in two physical locations with a separate route to
each location. You then create a cluster of machines to respond on a single
IP address. You connect these through a separate cluster interface and
situate half the cluster at each location. The interconnect will be
interesting, but it is possible.