[c-nsp] easy way to re-route sql traffic down alternate link?

[Rodney Dunn]

Well, actually if it's this simple you would just
PBR the traffic matching on an ACL on B for
the interface coming from 3 and redirect the traffic
to C.

You shouldn't have to anything special on C because
most likely the shortest path to A from C is not back
through B so once the traffic gets to C it will take
the normal path to A (C-A).

You'd have to do the same thing in reverse at A coming
back.

You could use SAA (now called IP SLA) and hook that in
to PBR so the PBR would fall back over to the B->A path
if C were to fail.

The GRE/route leaking really only works well if the servers
you are trying to reach are on a subnet by themselves and
and you cost them. Given the simplicity here I'd probably
just do straight PBR.


Rodney


 


On Tue, Apr 12, 2005 at 10:21:37AM -0700, Matt Bazan wrote:
> here's the goods:
>                        /1  
>                       /
>             A--------B--2
>              \      / \
>               \    /   \3 
>                \  / 
>                 C
> 
> this is a partial diagram of our network showing 3 of our 4 hubs (A, B,
> C) and some of the spoke branches (1, 2, 3).  In reality there is one
> more hub office and several more T1s connecting the hubs in full mesh.
> For simplicity sake I've diagramed as such to illustrate what I need.
> I'd like sql traffic from branch 3 to get to the sql servers in branch A
> by going through branch C (link between A and B is completely stuffed).
> 
> 
> Would PBR be the cleanest method for this?  Thanks.
> 
>   Matt
> 
> > -----Original Message-----
> > From: Rodney Dunn [mailto:rodunn at cisco.com] 
> > Sent: Tuesday, April 12, 2005 10:05 AM
> > To: Bruce Pinsky
> > Cc: Matt Bazan; cisco-nsp at puck.nether.net
> > Subject: Re: [c-nsp] easy way to re-route sql traffic down 
> > alternate link?
> > 
> > 
> > And depending on what your overall topology looks like it
> > might be easier to build a GRE tunnel through the network
> > and leak the route to the tunnel destination down the path
> > you want to pull the traffic down.  Then at the tunnel 
> > headend you apply PBR and route the traffic in the tunnel.
> > 
> > That way you might can get away without having to do PBR
> > on every single hop along the path.
> > 
> > Rodney