02-20-2012 02:09 PM - edited 03-07-2019 05:03 AM
Hi all,
i'm facing a strange problem with multicast routing. I have got a cisco3750 switch configured with different VLANs (just to keep things simple).
On VLAN 5 I have got a Linux box running Mediatomd dlna media server and on VLAN 6 I've got 2 different dlna clients : one Samsung TV and one Philips WAS7500 station. I configured both VLANs to be in dense-mode and the TV gets connected to the Media Server without problems, but the Philips stations doesn't. From the linux box i can ping the Philips stations (acutally the TV doesn't reply to ping which is a standard behaviour i guess). When trying to ping the multicast address both clients should be joining from the Linux box i don't get any reply. Please find hereafter some output i get from variuos show/debug commands from the switch :
CISCO3750G#sh ip igmp groups
IGMP Connected Group Membership
Group Address Interface Uptime Expires Last Reporter Gr
oup Accounted
239.255.255.250 Vlan6 00:42:56 00:02:50 192.168.2.137 (Philips station)
224.0.1.40 Vlan5 1d06h 00:01:57 192.168.2.1
CISCO3750G#sh ip mroute
IP Multicast Routing Table
Flags: D - Dense, S - Sparse, B - Bidir Group, s - SSM Group, C - Connected,
L - Local, P - Pruned, R - RP-bit set, F - Register flag,
T - SPT-bit set, J - Join SPT, M - MSDP created entry,
X - Proxy Join Timer Running, A - Candidate for MSDP Advertisement,
U - URD, I - Received Source Specific Host Report,
Z - Multicast Tunnel, z - MDT-data group sender,
Y - Joined MDT-data group, y - Sending to MDT-data group
V - RD & Vector, v - Vector
Outgoing interface flags: H - Hardware switched, A - Assert winner
Timers: Uptime/Expires
Interface state: Interface, Next-Hop or VCD, State/Mode
(*, 239.255.255.250), 3d02h/stopped, RP 192.168.2.129, flags: SJC
Incoming interface: Null, RPF nbr 0.0.0.0
Outgoing interface list:
Vlan6, Forward/Dense, 00:44:02/00:00:00
(192.168.2.137, 239.255.255.250), 01:22:45/00:02:58, flags: PT (Philips station)
Incoming interface: Vlan6, RPF nbr 0.0.0.0
Outgoing interface list: Null
(192.168.2.2, 239.255.255.250), 1d07h/00:02:38, flags: T (Linux box)
Incoming interface: Vlan5, RPF nbr 0.0.0.0
Outgoing interface list:
Vlan6, Forward/Dense, 00:44:02/00:00:00
(*, 224.0.1.40), 4d11h/00:02:48, RP 192.168.2.129, flags: SJCL
Incoming interface: Null, RPF nbr 0.0.0.0
Outgoing interface list:
Vlan5, Forward/Dense, 1d06h/00:00:00
CISCO3750G#sh ip mroute count
IP Multicast Statistics
4 routes using 2220 bytes of memory
2 groups, 1.00 average sources per group
Forwarding Counts: Pkt Count/Pkts(neg(-) = Drops) per second/Avg Pkt Size/Kilobi
ts per second
Other counts: Total/RPF failed/Other drops(OIF-null, rate-limit etc)
Group: 239.255.255.250, Source count: 2, Packets forwarded: 3986, Packets receiv
ed: 1197
RP-tree: Forwarding: 0/0/0/0, Other: 1192/0/1192
Source: 192.168.2.137/32, Forwarding: 502/1/1/0, Other: 4/0/0
Source: 192.168.2.2/32, Forwarding: 3484/0/1/0, Other: 1/0/0
Group: 224.0.1.40, Source count: 0, Packets forwarded: 0, Packets received: 0
CISCO3750G#sh ip mcache
IP Multicast Fast-Switching Cache
(192.168.2.137/32, 239.255.255.250), Vlan6, Last used: mdfs, MinMTU: 18010
(192.168.2.2/32, 239.255.255.250), Vlan5, Last used: mdfs, MinMTU: 1500
CISCO3750G#sh ip rpf 192.168.2.2
RPF information for ? (192.168.2.2)
RPF interface: Vlan5
RPF neighbor: ? (192.168.2.2) - directly connected
RPF route/mask: 192.168.2.0/25
RPF type: unicast (connected)
RPF recursion count: 0
Doing distance-preferred lookups across tables
CISCO3750G#sh ip rpf 192.168.2.137
RPF information for ? (192.168.2.137)
RPF interface: Vlan6
RPF neighbor: ? (192.168.2.137) - directly connected
RPF route/mask: 192.168.2.128/26
RPF type: unicast (connected)
RPF recursion count: 0
Doing distance-preferred lookups across tables
CISCO3750G#sh ip mroute active
Active IP Multicast Sources - sending >= 4 kbps
a negative Rate counts pps being fast-dropped
CISCO3750G#sh ip pim int
Address Interface Ver/ Nbr Query DR DR
Mode Count Intvl Prior
192.168.2.1 Vlan5 v2/D 0 30 1 192.168.2.1
192.168.2.129 Vlan6 v2/D 0 30 1 192.168.2.129
20 2012 22:55:00.209: MRT(0): Update Vlan6/239.255.255.250 in the olist of (*,239.255.255.250), Forward state - MAC not built
Feb 20 2012 22:55:00.209: MRT(0): Update Vlan6/239.255.255.250 in the olist of (192.168.2.2, 239.255.255.250), Forward state - MAC not built
Feb 20 2012 22:56:08.198: MRT(0): Update (*,239.255.255.250), RPF /0.0.0.0
Any help is really appreciated
Thanks
02-20-2012 07:53 PM
One quick note for you -- I have learned from experience that the 3560/3750 platform does not show accurate info for "show ip mroute count" as well as "show ip mroute active". So if you're wondering why you show no active sources, that is likely why!
Matt
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