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

[Rodney Dunn]

On Tue, Apr 12, 2005 at 12:22:53PM -0700, Matt Bazan wrote:
> Here's how I plan to set this up.  Looks very straightforward.  If
> anyone would have a sec to point out problems I'd be very appreciative:
> 
> SanRafael#(config) access-list 110 permit tcp any any eq 1433 //ACL for
> sql traffic
> SanRafael#(config) route-map SQL-Traffic permit
> SanRafael#(config-route-map) match ip address 110
> SanRafael#(config-route-map) set ip next hop <address of 'C' router> 
> 	//should I use an interface instead of IP here to insure proper
> route?

No.  I never recommend anyone use an interface as a next hop.

> SanRafael#(config) int fa0/0 
> SanRafael#(config-if) ip policy route map SQL-Traffic 
> 	//if i understand correctly, policy map needs to be applied to
> interface that policy traffic enters on.

Correct.

> 
> then setup reverse on the 'A' router.  anything else?  thanks again.

Correct.

You haven't looked in to the SAA stuff. Search for PBR object tracking
on CCO. If the link between A-C goes down PBR with your current setup will
send the SQL to C and C would route it back through B to get to A.
It will work but suboptimal.

PBR is just like static routes. By themselves they don't adjust
to changes in the network which usually makes them a bad idea.

You can path that somewhat with variations of SAA to detect a failure
in the path and change the forwarding behavior based on that change.

Rodney



>   Matt
>   
> > 
> > 
> > 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).
> > >