By definition every router participating in an area using a link-state routing protocol must have full information of all routes so that it can build a map of the network.
> -----Original Message----- > From: ericbrouwers [mailto:[EMAIL PROTECTED]] > Sent: Friday, January 31, 2003 8:10 AM > To: [EMAIL PROTECTED] > Subject: Why is distribute-list in not supported in OSPF? [7:62247] > > > Hello, > > The "distribute-list access-list in [interface]" command is > not supported in > IS-IS and OSPF. Why??? > > I tried to find an explanation in Cisco's OSPF design guide: > > ....Filtering information with link-state protocols such as > OSPF is a tricky > business. Distribute-list out works on the ASBR to filter > redistributed > routes > into other protocols. Distribute-list in works on any router > to prevent > routes > from being put in the routing table, but it does not prevent > link-state > packets from being propagated, downstream routers would still have the > routes. > It is better to avoid OSPF filtering as much as possible if > filters can be > applied on the other protocols to prevent loops.... > > Why can router not prevent link-state packets from being propagated??? > > Hope someone can explain this to me. Thanks, > > Eric Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=62252&t=62247 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
