[AusNOG] Routing Table Question

[Joshua Lehman]

Hi Noggers,

Just having a debate which I hope that someone can clairfy for me.

Do routers store the routing tables in order of longest mask to shortest
based on longest mask matching? When I do a show ip route on a cisco router
it does not appear that the list is any order.

The other techs I work with are telling me that the tables are stored in
memory and that they are not ordered as when you enter a new route it is
just added to the list, and that trying to sort the table could cause the
router to crash if it is large.

Other person says that the router would proccess the rules in correct order,
which would imply that there is some sort of linked list structure that
indicates the order of the rules.

It would seem logical to me that the rules would be sorted in some order but
why does the show ip route not display this is in order and what abouts the
other points regarding crashing the table when trying to sort a new entry?

I hope that this is not to off topic

Thanks

Josh
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