Hi,
OSPF is a link state protocol. That means, all routers within the same area have to maintain the same graph where the shortest path algorithm runs on.
If you want to filter routers, you can introduce areas different to the root area (id 0), let's say area 1, 2 and so on. So you could put your remote office router/switch in area 1 and your main office router in area 0. The be accorate, you put the interfaces facing the remote side into area 1 in the main office and you have to assign at least one interface into area 0, possibly a loopback interface.
If a router belongs to more then one area, it is called an area border router (ABR). On an ABR you can do filtering. If you want that the router in the rmeote office receives only a default route, area 1 would be called totally stub area. On the other hand, in area 0 you will still find the routes of area 1.
To explain everything in detail would exceed the possibilities of this thread. But you should be able continue working with this.
Here is a short example:
protocols {
ospf {
area 0.0.0.0 {
interface lo0.0 {
passive;
}
}
area 0.0.0.1 {
stub default-metric 10 no-summaries;
interface ge-0/0/0.0 {
metric 10;
}
interface ge-0/0/1.0 {
metric 20;
}
}
}
}
On your router in the remote area, you have to just mention the stub statement, without the default metric and no-summaries verbs.
I hope this helps a bit.
Regards,
Dominik
JNCIE et al.
--
The Axiom of Choice is obviously true, the well-ordering principle obviously false, and who can tell about Zorn's lemma?
