i have a router with one LAN interface and 2 wan interfaces connected to 2 internet ISP.
if i need to let some users go to internet via the first wan interface and some others via the second wan interface, normally i should use policy based routing (PBR)
-if i need automatic failure backup, i think i should use Reliable Static Routing Backup.
but if i need both! some users connect to one ISP and some others to the second and if one link fail all users switch to the functionning link, so how can we combine PBR and reliable static routing backup?
If you are using PBR and set a next hop f.e. 10.1.1.1 and the next hop is not available, because the interface is down, then normal routing will occur. This likely means in your case, that PBR alone offers the desired behaviour, i.e. send traffic to a specified link, if both interfaces to the two ISPs are available and use the remaining link for all traffic, if one interface fails.
The problem you could encounter is a link failure not being detected. Have a look at "PBR Support for Multiple Tracking Options"
This feature will allow you to use f.e. pings regularly sent by the router to detect a connectivity issue to an ISP and reroute to another path in case no connectivity exists.
Hope this helps! Please rate all posts.