I am confused with the route tagging between routing protocols. When i was going through different documents, i am not able to understand the tagging information. The configuration shows some tag number when redistributing between the routing protocols. Is it arbitary number picked in random? How this tag is helpful in preventing the loops, since most of the documents have the below format
route-map rip_to_eigrp deny 10
match tag 88
Route-map statement to deny any routes that have a tag of "88"
from being redistributed into EIGRP
route-map rip_to_eigrp permit 20
set tag 77
How do you know that the routes learned via rip will have tag of 88 and other non EIGRP routes as 77, unless there are some IP address matching the tag or am i missing some thing. Can any one help me explain or provide me with the links which has good referecence?
route tagging is a useful tool to perform mutual redistribution between two routing protocols specially if multiple border routers are used for mutual redistribution between two routing domains.
The idea is to tag routes differently depending on their original routing domain to avoid re-injection of routing information on different redistribution points (nodes) to original routing domain.
The tag values to be used are design choices
The logic is the following:
when redistributing RIP routes into EIGRP skip all routes with route-tag = 88 because that value means RIP routes that actually have been imported from the same EIGRP domain ( on the other border node or simply some time ago)
of remaining RIP routes accept them but tag them with value 77.
The design objectives are achieved by using a second route-map that performs a dual action and it is used for importing EIGRP routes into RIP.
! seed metric required for successful redistribution into EIGRP
default-metric 10000 100 1 255 1500
redistribute rip route-map rip_to_eigrp
the power of route tags is that they automatically adapt to changes: for example if a new prefix is added to EIGRP domain no changes in configuration are needed simply the new route will exist as not tagged route in EIGRP routing domain and as as a RIP route with tag 88 in the RIP routing domain.
Also the same configuration can be applied to both ASBR border routers.
This is actually a pretty cool feature, i didn't even know it existed until I was looking for a solution to advertise a subnet (prefix in BGP talk), only if a certain condition existed. This is exactly what conditional advertisements does
j ai une question j ai achete un routeur cisco 887VA-k9 , je le configuré avec la configuration ci- dessous
si je le lier avec mon pc portable sur l un de ses ports directement ça marche toute est bien ( la connexion internet + m...
Attached policy provides CLI access to the Cisco 4G router over text messaging. Two files are in the attached .tar file:
2. PDF with instructions on how to load and use the .tcl file.