Cisco 7507 not forwarding multicast packets
Ethan Haslett
have one last problem to be worked out. The basic problem is that the
router does not seem to forward any multicast packets on test multicast
groups that we set up.
For example: I have two interfaces (Fast Ethernet), connected to 3Com
3300 switches. Off of each of these, I have one host that is multicast capable
(one is Solaris, the other Linux). On either, I can use SDR to create a
test multicast group. I then can use either to be a source of traffic
for that group on the port number and address assigned. The packets
make it to the router, the receiver sends its join message appropriately
and everything seems to be as it should. A "show ip igmp group"
confirms that the receiver has joined. A "show ip mpacket <group>"
shows that the router does indeed receive packets. However, the
receiver never hears anything. I've run tcpdump to confirm that no
packets in the multicast group are being forwarded to the other
interface.
Here are the relevant (?) settings for the router's config:
ip multicast-routing
ip multicast cache-headers
no ip dvmrp route-limit
interface FastEthernet4/0/0
ip address x.x.x.x y.y.y.y
ip pim sparse-dense-mode
interface FastEthernet4/1/0
ip address w.w.w.w z.z.z.z
ip pim sparse-dense-mode
interface FastEthernet5/0/0
description Our link to the outside world and MBONE
ip address a.a.a.a b.b.b.b
ip pim sparse-dense-mode
no ip route-cache optimum
ip dvmrp unicast-routing
The unicast-routing is needed because we have two different links out to
the Internet at large.
Perhaps some useful info from when the tests are running (224.2.167.109
was the test multicast group address in this case):
#sho ip igmp groups
IGMP Connected Group Membership
Group Address Interface Uptime Expires Last Reporter
239.255.255.255 FastEthernet4/0/0 00:52:30 00:02:34 test source
239.255.255.255 FastEthernet5/0/0 5d03h never outside link
(a.a.a.a)
224.2.167.109 FastEthernet4/0/0 00:23:54 never test source
224.2.167.109 FastEthernet4/1/0 00:41:07 never test recv'r
224.2.127.253 FastEthernet4/0/0 00:52:32 00:02:32 test source
224.1.127.255 FastEthernet4/0/0 00:52:26 00:02:29 test source
224.2.127.254 FastEthernet4/0/0 00:52:32 00:02:32 test source
224.2.127.254 FastEthernet5/0/0 5d03h never outside link
224.2.255.116 FastEthernet4/0/0 00:52:29 00:02:25 test source
224.2.129.29 FastEthernet4/0/0 00:52:33 00:02:31 test source
#sho ip mroute 224.2.167.109
(*, 224.2.167.109), 01:56:18/00:00:00, RP 0.0.0.0, flags: DJCL
Incoming interface: Null, RPF nbr 0.0.0.0
Outgoing interface list:
FastEthernet4/0/0, Forward/Sparse-Dense, 00:19:44/00:00:00
FastEthernet4/1/0, Forward/Sparse-Dense, 00:36:58/00:00:00
#show ip mpacket 224.2.167.109
IP Multicast Header Cache - entry count: 1882, next index: 859
Key: id/ttl timestamp (name) source group
747C/1 446472.580 (test source) test-source-ip-addr 224.2.167.109
747D/1 446472.680 (test source) test-source-ip-addr 224.2.167.109
(many entries of this type)
#show ip igmp interfaces
FastEthernet4/0/0 is up, line protocol is up
Internet address is x.x.x.x/yy
IGMP is enabled on interface
Current IGMP version is 2
CGMP is disabled on interface
IGMP query interval is 60 seconds
IGMP querier timeout is 120 seconds
IGMP max query response time is 10 seconds
Inbound IGMP access group is not set
IGMP activity: 8 joins, 2 leaves
Multicast routing is enabled on interface
Multicast TTL threshold is 0
Multicast designated router (DR) is x.x.x.x (this system)
IGMP querying router is x.x.x.x (this system)
No multicast groups joined
FastEthernet4/1/0 is up, line protocol is up
Internet address is w.w.w.w/zz
IGMP is enabled on interface
Current IGMP version is 2
CGMP is disabled on interface
IGMP query interval is 60 seconds
IGMP querier timeout is 120 seconds
IGMP max query response time is 10 seconds
Inbound IGMP access group is not set
IGMP activity: 3 joins, 2 leaves
Multicast routing is enabled on interface
Multicast TTL threshold is 0
Multicast designated router (DR) is w.w.w.w (this system)
IGMP querying router is w.w.w.w (this system)
No multicast groups joined
FastEthernet5/0/0 is up, line protocol is up
Internet address is a.a.a.a/bb
IGMP is enabled on interface
Current IGMP version is 2
CGMP is disabled on interface
IGMP query interval is 60 seconds
IGMP querier timeout is 120 seconds
IGMP max query response time is 10 seconds
Inbound IGMP access group is not set
IGMP activity: 3 joins, 1 leaves
Multicast routing is enabled on interface
Multicast TTL threshold is 0
Multicast designated router (DR) is a.a.a.a (this system)
IGMP querying router is router-on-other-end
DVMRP unicast routing is enabled
5 DVMRP routes + 0 poison-reverse routes received in last 00:00:26
3/1 Unicast/DVMRP routes last advertised by DVMRP
DVMRP output report delay is 100 ms, with burst size of 2
Multicast groups joined: 224.2.127.254 239.255.255.255
Thanks,
Ethan
--
Ethan Haslett UMass Computer Science Computing Facility A313 LGRC
et...@cs.umass.edu (413)545-4296 FAX:(413)545-1249
http://www.cs.umass.edu/~ethan/