Carlos, You are very likely to find a scenario that is "best" solved using route tagging in your lab exam.
-- Marko Milivojevic - CCIE #18427 Senior Technical Instructor - IPexpert FREE CCIE training: http://bit.ly/vLecture Mailto: [email protected] Telephone: +1.810.326.1444 Web: http://www.ipexpert.com/ On Fri, Dec 10, 2010 at 12:00, Carlos Valero <[email protected]> wrote: > > Hello, > > *I have a general question about Route Tagging.* > > Although the general idea seems pretty simple, > the actual implementation can be VERY complex and it usually leads to BIG > mess! > > So my question is: > > *How likely are we to find Route Tagging Lab scenarios in the real CCIE > Lab Exam? > * > > I had been told that it is very unlikely that we'll have to deal with it in > the Exam. > > *Is that true? *Should I not pay too much attention to it and basically > "gamble" on the possibility of NOT finding it in the real Lab Exam? > > > *How about real life?* > > Does anyone really mess with these Tags in real life? > > Or is it a seldom use feature as so many obscure IOS features? > > I hope somebody can shed some light on this. > > Thanks!! > > > --- On *Mon, 11/2/09, Vikas Sharma <[email protected]>* wrote: > > > From: Vikas Sharma <[email protected]> > Subject: [OSL | CCIE_RS] Route tagging and redistribution between an IGP > and EGP > To: "CCIE_RS OnlineStudyList" <[email protected]> > Date: Monday, November 2, 2009, 7:13 PM > > Hi Guys, > > I need your help out here. I have created a lab in GNS as follows: > > R0 - R1 - R2 - R3 all run EIGRP. > > R2 - R3 - R4 run BGP as well. > > R2 - R3 redistribute EIGRP into BGP and vice versa. > > I am attaching a zip file with the drawing plus configs and the NET file. > > The intention of this lab is as follows. > > > 1. R0 and R1 simulate 2 client sites connected together. > 2. We have a route map on each router that sets tags on routes that are > not local to that particular site. > 3. This route map is applied to a distribute list in the direction of > routers R2 and R3 respectively. > 4. I managed to get the EIGRP part working. > 5. However, as far as tagging routes is concerned, for some reason R1 > has stopped tagging routes to send them onwards to R3. It worked yesterday > and not today and I wonder if this is a GNS thing. > 6. On R2 and R3 there is another route map that looks for tags and then > does an as-prepend to make tagged routes more expensive and send them to R4 > which is like a remote site router. The idea is that BGP must see 2 paths > which we influence, in its routing table and should one of the sites > (either > R0 or R1) goes off the air it should automatically be able to use the > second > path to reach that network. > 7. When I apply the redistribute statement with the route map in BGP on > routers R2 and R3, I find that the BGP routing table has only a few > networks > learnt and no alternative path. > 8. I then took off the redistribute eigrp statement off the BGP config > and re-added it in without the route-map and lo and behold, I see all the > routes on R4 and each have an alternative path. Result is exactly as I want > but I want to influence the routes in BGP. So, basically, if routes > originating on R0 and seen on R2, the routing on R4 for those networks > should be via R2 and not R3. Right now I'm not able to influence these > routing decisions. > > However, without the route-map, it works beautifully but I want to use > route tagging to influence how BGP decides where to route and have an > alternative path. > > I look forward to your feedback. > > Cheers, > > -- > Vikas Sharma > Network Specialist > Fujitsu Australia > (M): 0421 052 117 > > -----Inline Attachment Follows----- > > _______________________________________________ > For more information regarding industry leading CCIE Lab training, please > visit www.ipexpert.com > > > > _______________________________________________ > For more information regarding industry leading CCIE Lab training, please > visit www.ipexpert.com > >
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