From: Brian Dennis (bdennis@internetworkexpert.com)
Date: Wed Dec 07 2005 - 03:14:32 GMT-3
This isn't pretty but here goes:
R1 and R4 are connected via Ethernet (155.1.146.0/24) and R4 is
redistributing OSPF into RIP. R4 is setting the tag for these routes to
4110. I used 4110 because its R4's OSPF routes (4 for R4 and 110 for
OSPF's administrative distance) but any number would work.
Rack1R4#sho run | be router rip
router rip
version 2
redistribute ospf 1 metric 5 route-map OSPF->RIP
network 155.1.0.0
no auto-summary
!
route-map OSPF->RIP permit 10
set tag 4110
We'll match the RIP updates from R4 on R1 with an ACL and use the hidden
"dump" option on the debug ip packet command along with the ACL so that
we can view the whole RIP packet.
Rack1R1#
Rack1R1#conf t
Enter configuration commands, one per line. End with CNTL/Z.
Rack1R1(config)#access-list 100 permit udp host 155.1.146.4 any eq rip
Rack1R1(config)#^Z
Rack1R1#deb ip pack 100 dump
IP packet debugging is on (dump) for access list 100
Rack1R1#
*Mar 1 10:45:50.661: IP: s=155.1.146.4 (FastEthernet0/0), d=224.0.0.9,
len 372, rcvd 2
03C036C0: 0100 5E000009 ..^...
03C036D0: 0030947E E5820800 45C00174 00000000 .0.~e...E@.t....
03C036E0: 0111AAAA 9B019204 E0000009 02080208 ..**....`.......
03C036F0: 0160A3B0 02020000 0002100E 96010000 .`#0............
03C03700: FFFF0000 00000000 00000005 00020000 ................
03C03710: 96010200 FFFFFF00 00000000 00000003 ................
03C03720: 00020000 96010400 FFFFFF00 00000000 ................
03C03730: 00000001 00020000 96010500 FFFFFF00 ................
03C03740: 00000000 00000002 0002100E 96010808 ................
03C03750: FFFFFFFF 00000000 00000005 00020000 ................
03C03760: 9B010000 FFFFFF00 00000000 00000001 ................
03C03770: 0002100E 9B010500 FFFFFF00 00000000 ................
03C03780: 00000005 0002100E 9B010700 FFFFFF00 ................
03C03790: 00000000 00000005 0002100E 9B010800 ................
Rack1R1#
Let's take this line and break it down:
03C03770: 0002100E 9B010500 FFFFFF00 00000000 ................
02 means its address family is IP. 100E is the tag in hex (4110 in
decimal). 9B is 155. 01 is 1. 05 is 5 and finally 00 is 0. FFFFFF00 is
255.255.255.0 for the subnet mask of the route so this is network
155.1.5.0/24 with a tag of 4110.
So okay there may be a better way but this way is really cool. Also
remember that the calculator is your friend when looking at packet dumps
;-)
HTH,
Brian Dennis, CCIE #2210 (R&S/ISP-Dial/Security)
bdennis@internetworkexpert.com
Internetwork Expert, Inc.
http://www.InternetworkExpert.com
Toll Free: 877-224-8987
Direct: 775-745-6404 (Outside the US and Canada)
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
Anthony Sequeira
Sent: Tuesday, December 06, 2005 7:40 PM
To: Cisco certification
Subject: Verifying Route Tags
Hi all!
Just wanted to make sure that I understand the most efficient ways to
verify
route tags:
For EIGRP - show ip eigrp topology
For OSPF - show ip ospf database
For RIP - ??????
This archive was generated by hypermail 2.1.4 : Mon Jan 09 2006 - 07:07:50 GMT-3