Re: EIGRP OSPF DUAL MUTUAL REDISTRIBUTION [7:70643]
Jason, Chuck answered pretty completely, but there's another option that works well, changing administrative distances. At the redistribution points, set the default administrative distance for each protocol to something like 200. Next create an access-list that identifies all routes internal to each routing domain, and override the default administrative distance (200) with the normal AD (something less than 200). This has the effect of assigning all 'internal' routes the normal AD, and prevents route feedback. Routes will only be redistributed if they are not already present in the internal table. This also has the advantage of providing additional redundancy. If a route becomes inaccessible for some reason, but is still available via another routing protocol, it will be learned using the alternate path. With route filtering this is not possible. A very good explanation of this can be found in Chapter 13 of Doyle's TCP/IP Routing Vol. I. - Tom Jason Viera wrote: Can't figure this one out. I am mutually redistributing eigrp into ospf (dual redistribution points) and vice versa, I also have a separate redistribution point in the eigrp domain which introduces external (AD170) routes into the Eigrp domain, upon redistribution into OSPF these (external eigrp) routes are given an AD of 110, creating suboptimal routing. The only solution I could devise was based on modifying the distance of the external routes in the eigrp domain. What would be the best approach to tackle the problem, Any insight would be greatly appreciated!! Thanks Jason Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=70716t=70643 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: EIGRP OSPF DUAL MUTUAL REDISTRIBUTION [7:70643]
Jason Viera wrote in message news:[EMAIL PROTECTED] Can't figure this one out. I am mutually redistributing eigrp into ospf (dual redistribution points) and vice versa, I also have a separate redistribution point in the eigrp domain which introduces external (AD170) routes into the Eigrp domain, upon redistribution into OSPF these (external eigrp) routes are given an AD of 110, creating suboptimal routing. The only solution I could devise was based on modifying the distance of the external routes in the eigrp domain. What would be the best approach to tackle the problem, Any insight would be greatly appreciated!! Thanks Jason A couple of things come to mind. Distribute-lists assuming your routing domains exhibet any kind of rational organization, you could filterthose routes wihich are re-entering and being trashed by the lower OSPF admin distance. Prefix-lists also assuming there is some rhyme and reason to the domain organizations. I've gotten to where I like prefix-lists better than distribute-lists. As with anything networking, their usefulness depends on a lot of things. Route-maps similar to distribute-lists can use an access-list or a prefix-list as the seed Route tags ( used with route-maps ) gets a little trickier. your access-lists have to be right on. assign a tag value to routes coming in from one domain into the other, then filter those at the other redistribution point. come to think of it, you may be able to tag the routes coming into either domain using the redistribute command switch. (checks CCO) yeah, looks like it. You could also filter from EIGRP into OSPF by filtering EIGRP external routes - this would block routes that originated with OSPF from gong back into the domain. Not that it matters a lot because of the admin distance. A better way would be to filter OSPF external routes from entering the EIGRP domain. This can cause havoc if you have an ABSR somewhere and need those externals to get to EIGRP. gets complex fast, doen't it :- depending upon the level of expertise for which you are sudying, you may want to have all of these tools as part of your bag of tricks. never can tell when they might be useful. HTH Chuck Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=70660t=70643 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
EIGRP OSPF DUAL MUTUAL REDISTRIBUTION [7:70643]
Can't figure this one out. I am mutually redistributing eigrp into ospf (dual redistribution points) and vice versa, I also have a separate redistribution point in the eigrp domain which introduces external (AD170) routes into the Eigrp domain, upon redistribution into OSPF these (external eigrp) routes are given an AD of 110, creating suboptimal routing. The only solution I could devise was based on modifying the distance of the external routes in the eigrp domain. What would be the best approach to tackle the problem, Any insight would be greatly appreciated!! Thanks Jason Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=70643t=70643 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
