From: Aberdeen Appointments Agency ("Broad,)
Date: Fri Dec 28 2007 - 14:17:04 ART
Hi,
We have a strange issue with route tagging, just wondering if anyone had
come across it before.
We have an EIGRP Network with five devices in it. Two of the devices do
BGP and run iBGP between them (call them router1 and router2). (They
also have eBGP connections out to the WAN.)
Routes come in through BGP and get redistributed into EIGRP with a route
map to set a tag of 179.
There is mutual redistribution of EIGRP back into BGP on both but with a
route map to block any networks tagged with 179.
The issue is that the tag is only seen on the router doing the
redistribution and on one other device (router3)
Router 2 , Router 4 and router 5 see all the routes in EIGRP but with no
tag.
If I add a static route with a tag on Router 4 and redistribute it into
EIGRP - all the routers see the tag on this route.
I have cleared the EIGRP neighbour relationship between Router 4 and
Router1 and still cannot see the tags.
As far as I know, a tag is a tag and all routers/layer 3 switches should
see it? There are a number of ways to get round the issue but it would
be nice to know why its happening. I don't think it can be a bug can it?
- unless its something strange with the code of the 3560 switches?
For info
Router 1 is a WS-C3560-24PS running 12.2(40)SE
Router 2 is a 3725 running 12.2(11)T6
Router 3 is a WS-C3560-24PS running 12.2(40)SE
Router 4 and 5 are 6509 switches running IOS version 12.2(17d)SXB11a
Routers 1, 2 and 3 are in the same vlan.
Routers 1, 3, 4 and 5 are all connected to each other.
Some output-
Router1#sh ip eigrp top 155.191.200.0/26
EIGRP-IPv4 (AS 66): Topology Default-IP-Routing-Table(0) entry for
155.191.200.0/26
State is Passive, Query origin flag is 1, 1 Successor(s), FD is 630016
Routing Descriptor Blocks:
154.46.215.49, from Redistributed, Send flag is 0x0
Composite metric is (630016/0), Route is External
Vector metric:
Minimum bandwidth is 4096 Kbit
Total delay is 200 microseconds
Reliability is 255/255
Load is 1/255
Minimum MTU is 4470
Hop count is 0
External data:
Originating router is 154.46.127.48 (this system)
AS number of route is 64615
External protocol is BGP, external metric is 19712
Administrator tag is 179 (0x000000B3)
Router2#sh ip eigrp top 155.191.200.0/26
IP-EIGRP (AS 66): Topology entry for 155.191.200.0/26
State is Passive, Query origin flag is 1, 1 Successor(s), FD is 632576
Routing Descriptor Blocks:
154.46.136.43 (FastEthernet0/0), from 154.46.136.43, Send flag is 0x0
Composite metric is (632576/630016), Route is External
Vector metric:
Minimum bandwidth is 4096 Kbit
Total delay is 300 microseconds
Reliability is 255/255
Load is 1/255
Minimum MTU is 1500
Hop count is 1
External data:
Originating router is 154.46.127.48
AS number of route is 64615
External protocol is BGP, external metric is 19712
Administrator tag is 0 (0x00000000)
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