I have a network that running RIP, and two paths can go from network a to network b. But there is only one routing from network a to network b in the routing table due to hop count (one is 3 the other is 4). But I want to load balance between the two link. Can I use static route and set the administrative distance to 120 for another path to provide load balance of the network? Thank you!
Never actually tried this as there are prefered methods to be used instead of this... but thinking it through route selection is based on prefix length, admin distance and metrics.
Prefix length - longer prefixes are always preferred over shorter ones when forwarding a packet, but I assume you placed the static route with an equal length of the rip route (eg both 255.255.255.0). If not only one route is selected for forwarding packets.
eg 192.168.1.0/24 is learned via ospf and 192.168.1.0/27 learned via rip. As each of these routes has a different prefix length (subnet mask), they're considered different destinations, and they will both be installed in the routing table. A packet for 192.168.1.1 will go out the ospf path but a packet for 192.168.1.40 will go out the rip path.
The router decides whether or not to install routes presented by the routing processes based on the administrative distance of the route in question. If this path has the lowest administrative distance to this destination (when compared to the other routes in the table), it's installed in the routing table. If this route isn't the route with the best administrative distance, then the route is rejected. Eg. rip 192.168.1.0/24 and ospf 192.168.1.0/24, ospf is selected (same prefix length - therefore same destination, different admin distance). Your admin distance is equal, so both are placed in the routing table.
Metrics are used to compare routes between the same routing process (eg EIGRP), when they have the same prefix length.
So I believe both (as have same admin distance and same length) are in the route table and can load balance.
A more common method would be an offset-list to increase or decrease the number of hops of the rip routes (to make paths equal in hops).
eg. offset-list 21 in 10 ethernet 0 (an offset of 10 to routes on acl 21 learned from Ethernet interface 0)
"eg 192.168.1.0/24 is learned via ospf and 192.168.1.0/27 learned via rip. As each of these routes has a different prefix length (subnet mask), they're considered different destinations, and they will both be installed in the routing table. A packet for 192.168.1.1 will go out the ospf path but a packet for 192.168.1.40 will go out the rip path."
A packet for 192.168.1.1 is matched against both the route 192.168.1.0/24 and 192.168.1.0/27 and by longest match rule, it should be forwarded via rip path.
192.168.1.40 doesnt match against 192.168.1.0/27. (it would have matched against 192.168.1.32/27, though). It will only be matched against 192.168.1.0/24. SO it would be forwarded via the ospf route.
This is actually a pretty cool feature, i didn't even know it existed until I was looking for a solution to advertise a subnet (prefix in BGP talk), only if a certain condition existed. This is exactly what conditional advertisements does
j ai une question j ai achete un routeur cisco 887VA-k9 , je le configuré avec la configuration ci- dessous
si je le lier avec mon pc portable sur l un de ses ports directement ça marche toute est bien ( la connexion internet + m...
Attached policy provides CLI access to the Cisco 4G router over text messaging. Two files are in the attached .tar file:
2. PDF with instructions on how to load and use the .tcl file.