Dear all,
I faced a weird problem while doing the Multicast sections in IPX VOL 2 Lab
3 and Lab4. In both these labs i found that the multicast traffic is being
encapsulated by the routers in an MPLS packet the label used for this
traffic is the label assigned by BGP to the default route.
An example of this traffic is shown below.
IPX VOL 2 Lab 4:
*While the default route is installed:*
The output shown below is taken from R6 which is has joined the group
239.200.200.6 and R7 (100.100.100.7) from AS 100 is trying to ping this
group.
Also the following debugs is running on R6
R6#sh debugging
Generic IP:
IP multicast packets debugging is on for group 239.200.200.6 (detailed)
MPLS Packet:
Packet debugging is on with ACL 2700
R6#sh ip bgp labels
Network Next Hop In label/Out label
0.0.0.0 21.1.6.21 34/nolabel
01:36:49: %BGP-5-ADJCHANGE: neighbor 21.1.6.21 Up
R6#
01:36:51: MPLS les: Se4/0.604: rx: Len 108 Stack {34 0 253} - ipv4 data
R6#
01:36:53: MPLS les: Se4/0.604: rx: Len 108 Stack {34 0 253} - ipv4 data
R6#
01:36:55: MPLS les: Se4/0.604: rx: Len 108 Stack {34 0 253} - ipv4 data
R6#
01:36:57: MPLS les: Se4/0.604: rx: Len 108 Stack {34 0 253} - ipv4 data
R6#
01:36:59: MPLS les: Se4/0.604: rx: Len 108 Stack {34 0 253} - ipv4 data
At this point the ping from R7 to R6 is unsuccessful
*The default route is withdrawn:*
01:39:53: %BGP-5-ADJCHANGE: neighbor 21.1.6.21 Down Peer closed the session
R6#
01:39:55: IP(0): MAC sa=DLCI 604 (Serial4/0.604)
01:39:55: IP(0): IP tos=0x0, len=100, id=866, ttl=252, prot=1
R6#
01:39:57: IP(0): MAC sa=DLCI 604 (Serial4/0.604)
01:39:57: IP(0): IP tos=0x0, len=100, id=867, ttl=252, prot=1
R6#
01:39:59: IP(0): MAC sa=DLCI 604 (Serial4/0.604)
01:39:59: IP(0): IP tos=0x0, len=100, id=868, ttl=252, prot=1
R6#
01:40:01: IP(0): MAC sa=DLCI 604 (Serial4/0.604)
01:40:01: IP(0): IP tos=0x0, len=100, id=869, ttl=252, prot=1
R6#
01:40:03: IP(0): MAC sa=DLCI 604 (Serial4/0.604)
01:40:03: IP(0): IP tos=0x0, len=100, id=870, ttl=252, prot=1
The multicast traffic is now not MPLS encapsulated and the ping is now
successfull.
Any help regarding this problem is much appreciated.
*Note:*
The Routers that exhibit this issue are running IOS 12.2S
Cisco IOS Software, 7200 Software (C7200-P-M), Version 12.2(25)S15, RELEASE
SOFTWARE (fc1)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2007 by Cisco Systems, Inc.
Compiled Fri 07-Dec-07 18:26 by tinhuang
ROM: ROMMON Emulation Microcode
BOOTLDR: 7200 Software (C7200-P-M), Version 12.2(25)S15, RELEASE SOFTWARE
(fc1)
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