How to make a forwarding decision when there are 2 forwarding routes

[ztj108000]

For example:

OSPF IA 192.168.19.20/29 [110/3] via 192.168.17.5

                                        [110/3] via 192.168.18.21

Router will alway use the first one or randomly choose the better one?

[Jon Marshall]

Kevin

There is no better one as they are equal cost paths. So the router will alternate between them.

It does this either on -

1) a per packet basis

or

2) a per destination IP basis. This is the default and is the most commonly used.

A routing protocol such as EIGRP/OSPF will automatically use both paths and both can be configured as to how many equal cost paths they can use.

BGP on the other hand does not do this automatically and you need additional configuration to make it work.

Jon