I have two T1 lines from different providers and the requirement is to
have the end-users default route be the one ISP and the servers
default route the other ISP. Additionally, there needs to be a way
for automatic failover should one of the lines fail. The final
challenge is that all the traffic is coming from a 5510 ASA. The
switches on the inside of the ASA are unmanaged but the servers
connect to one switch and the workstations another so I can physically
separate them and configure an interface on the ASA for each group.
I know it is a relatively simple task if all traffic goes out one line
and the other is strictly failover. The crux of a solution like this
would be a tracked default route, multiple route-maps, and multiple
NAT statements. However, for the requirements mentioned above I am
thinking of using route-maps setting the next hop of the preferred
path and then the secondary path. The servers with static mappings
are just hosed unless someone manually configures them with the
secondary ISPs IP addresses or have an alternate config ready. I am
never thrilled with a solution that requires manual input but it may
be the chosen path. I would set IP precendence (or some other QoS
marking scheme) for the workstation traffic to be able to distinguish
it from server traffic and thus determine what route it takes.
I think all in all BGP would be the best bet provided I can get a /24
from one of the providers and both support BGP. However, just in case
I am lining up other non-BGP alternatives.
Open to all thoughts and ideas. Thank you.
||2/15/2008 2:48:39 AM