SD-WAN

So, here is my setup: I've got a single WAN interface on my 128T router. This interface is connected to the Internet, and is also used to peer with some other 128T routers. I've got a ""Internet"" service (`0.0.0.0/0`) that I'd like to route via a peer router when the peer is available, but use a static-route directly to Internet when the peer is unavailable. ¾ I've set up the following 2 service-routes for my Internet service, and also given it a service-policy with a load balancing strategy of `hunt`: [Start code block] [End code block][Start code block] [End code block]So my question at this point, is how do I influence the hunt across these 2 service-routes to start with one (`peer-internet`) and hunt to the other (`static-internet`) when the first is not available?

Comment on the use of ""static route"" term: in 128T data model I like to distinguish all routes as either service routes or static routes. Service routes can further be categorized into two types, Service-Agent or Peer. Static routes are created in routing ""default-instance"" of a router, and have no relation to a service. Static routes show up in the RIB as ""S-routes"". Service Routes are ""K-routes"" in the RIB. Just to clarify, what {@0051J000004hN3RQAU}? refers to as a ""static route"" is really a Service-Agent Type service route in 128T terminology. Minor point, but something I wanted to call out to avoid any confusion.

Hi Greg, thanks for asking! Our load balancing is based on capacity, so you'll need to let your 128T know the capacities of the two different service-routes. This is done by creating service-route-policy objects, and associating them to the service-routes.

 

E.g., you can create a set of service-route-policy elements such as:

service-route-policy largeServer name largeServer description ""big webserver"" max-sessions 10000 exit service-route-policy smallServer name smallServer description ""small webserver"" max-sessions 1000 exit

Then, for example, assign the largeServer policy to one service-route and smallServer to another.

 

By design, the hunt technique will start filling up service-routes beginning with the ones with the most available capacity.

 

Also note, and this is a subtle point, that you don't need load balancing to accomplish what you've asked for in the OP. You could use vectors to prefer one path over another, and not use load balancing. The load balancing piece will take capacity (load) into account where the vectors will not, however.

When two service-routes have service-route-policies with the same max-sessions, the service-route name will be used as the tie breaker between the two service-routes. The service-route names are sorted alphanumerically.

Thanks Patrick A Timmons and Michael Baj ! I just set up the following service-route policies:

service-route-policy max-sessions name max-sessions description ""Maximum possible sessions for a service-route-policy (used for influencing hunt lb-strategy)"" max-sessions 999999999999 exitservice-route-policy max-sessions-1 name max-sessions-1 description ""Maximum possible sessions for a service-route-policy, minus 1 (used for influencing hunt lb-strategy)"" max-sessions 999999999998 exit

....and applied them like so:

service-route peer-internet name peer-internet service-name internet peer my-peer service-route-policy max-sessions exitservice-route static-internet name static-internet service-name internet ¾ next-hop my-node wan node-name my-node interface wan exit service-route-policy max-sessions-1 exit

...and it appears to be working as needed!

 

Regarding your point on vectors, in my case the peer and the static route use the exact same WAN network-interface. Is it possible to use vectors in this case?

 

Perhaps I could have 2 neighborhoods on the same interface: one shared with my peer router, and the other unique to that just that interface. Then perhaps the vector method of doing this would work?

It looks like I read your question too quickly, and missed the part about a single WAN interface. Sorry! Vectors won't let you prioritize over a single WAN interface, they let you prioritize between multiple interfaces. I'm glad you got the service-route-policy working!