Tagging routes... why, exactly?
Yeah, I don't get it. I hope it's not so blatantly obvious that I feel silly, but I can't find any real value to tagging redistributed routes.
IE...
route-map OSFP-into-EIGRP permit 10
match ip next-hop 10.22.150.1
set tag 5
What's the tag do?
If I do a "sh ip eig topo 10.22.151.0 255.255.255.0 | in tag" then sure, the output says "Administrator tag is 5", but is there any real value to this number? I don't see how it matters.
Preciate your thoughts.
IE...
route-map OSFP-into-EIGRP permit 10
match ip next-hop 10.22.150.1
set tag 5
What's the tag do?
If I do a "sh ip eig topo 10.22.151.0 255.255.255.0 | in tag" then sure, the output says "Administrator tag is 5", but is there any real value to this number? I don't see how it matters.
Preciate your thoughts.
There are only 10 kinds of people... those who understand binary, and those that don't.
CCIE Studies: Written passed: Jan 21/12 Lab Prep: Hours reading: 385. Hours labbing: 110
Taking a time-out to add the CCVP. Capitalizing on a current IPT pilot project.
CCIE Studies: Written passed: Jan 21/12 Lab Prep: Hours reading: 385. Hours labbing: 110
Taking a time-out to add the CCVP. Capitalizing on a current IPT pilot project.
Comments
In your example , since routes are tagged 5 , if you wanted to deny this set routes to somewhere else, you could simply setup another route map to do that based on the tag value.
route-map DENY-NH-10.22.150.1 20
match tag 5
All in all, it's just another way to do things.
Redistributing Routing Protocols - Cisco Systems
The big benefit is that you don't have to keep up with multiple distribute lists and corresponding ACLs when you add an external route - you just tag the route and if there are distribute lists already in place to block that tag, then you're good to go
I mean, in my example, I just created a "permit" route map. So I want this route to be redistributed. Otherewise, I wouldn't have matched it, and it would have been omitted by the implicit deny. If they're only locally significant, then I don't see when I would want to permit the route to be redistributed into another protocol, just to turn around and use the tag to deny it.
What am I missing?
CCIE Studies: Written passed: Jan 21/12 Lab Prep: Hours reading: 385. Hours labbing: 110
Taking a time-out to add the CCVP. Capitalizing on a current IPT pilot project.
Sure you can do it a variety of ways.. it's just another way available to you.
- G.K. Chesterton