[j-nsp] Subject: Alternatives to floating static routes?

[Anton Smith]

Hi Dario,

Dario wrote:
> Hi all,
> 
> We need to develop a solution to provide redundancy for two of our clientes, connected to us via our 
> Cisco Catalyst 2950.
> 
> This is the topology:
>                                   [FastEth]
> 	Router Customer 1	------------- |                   [GigaEth]
> 					         |  Cat 2950 --------------- Juniper M40e
> 	Router Customer 2	------------- |              
>                                   [FastEth]
> 
> Right now we have static routes in our Juniper to connect with each customer. The customers have the
> posibility to connect their routers. Each one request us to reroute its networks via the other customer when
> its link fails.
> 
> We first think in floating static routes, two routes for each customer, the actual one and other via the 
> other customer with more metric.
> 
> But it'll no work because if for example the link between the Customer 1 and our CAT 2950 fails, our 
> Juniper see the link with the CAT 2950 up (no possibility to configure keepalives), then the active route 
> is the static route without metric, it never changes to the floating route.
> 
> BGP (using prepends,...) is a solution but we prefer another one if possible. Any ideas?
> 
> Many thanks and best regards,
> 
> 	Dario D.

Here´s an alternative for you if you don´t want to run a routing 
protocol with your customers.

Consider using VRRP or HSRP between the two customer routers across the 
cat 2950. Run two groups, e.g. virtual addresses .1 and .2. For .1, make 
customer 1 the primary. And for .2, make customer 2 the primary.

On the Juniper, add a static route for customer 1 via .1, and a static 
route for customer 2 via .2.

On customer router 1, add a static for customer 2's network(s) via the 
direct link between them (next hop is cust 2 router). And vice versa on 
customer router 2.

Under normal circumstances, traffic for customer 1 will flow directly to 
router 1 (next hop .1). Traffic for customer 2 will flow to router 2. If 
there is a break between either customer and the switch, then the other 
router will assume control of the VRRP/HSRP group and traffic will start 
flowing  to the other router, where it is then sent across the direct link.

Are you planning on setting defaults on the customer routers via the 
M40e, with floating defaults via the other customer's router?

Regards,
Anton