IP PIM MULTICAST PROBLEM

[a_mrk]

We have enabled multicast videoconferencing in our

lan and wan.

1) The lan is segmented with vlan configuration and

L 3 Switch.

2) IP PIM is enabled in vlan 1 and vlan 16.

3) The WAN router sits in vlan 1.

4) The multicast video reaches the hosts in vlan 16

from the branches through the wan router.

5) The multicast video from the hosts in vlan 16

does not reach the hosts in branches.

6) The above problem gets rectified and everything

is fine if a host in vlan 1 joins the

conference.

7) Is is it a RPF issue ? What should be done to

solve the problem without a host from vlan 1

joining the conference.

M.Radhakrishnan

mrk@thehindu.co.in

[smif101]

Please add your configs

[a_mrk]

Thankyou Mr. Smif.

I am enclosing the reqd. conf. of the 2 L3 switches

running HSRP and the WAN ROUTER.

L3 switch 1

--------------

!

ip multicast-routing

!

spanning-tree vlan 1,10,24,40,64,200 priority 16384

!

interface Vlan1

description " *** Network Routers & Switches VLAN ***"

ip address 10.10.0.1 255.255.248.0

no ip redirects

ip pim sparse-dense-mode

ip cgmp

standby 1 ip 10.10.7.254

standby 1 priority 200

standby 1 preempt

!

!

interface Vlan16

ip address 10.10.23.252 255.255.248.0

ip helper-address 10.10.16.29

no ip redirects

ip pim sparse-dense-mode

ip cgmp

standby 3 ip 10.10.23.254

standby 3 priority 50

router eigrp 100

network 10.0.0.0

network 192.168.200.0

auto-summary

no eigrp log-neighbor-changes

ip pim rp-address 1.1.1.1 20

access-list 20 deny 224.0.1.39

access-list 20 deny 224.0.1.40

access-list 20 permit 224.0.0.0 15.255.255.255

L3 SWITCH 2

-------------

ip multicast-routing

!

spanning-tree vlan 16,32,48,56 priority 16384

!

!

!

interface Vlan1

ip address 10.10.0.2 255.255.248.0

no ip redirects

ip pim sparse-dense-mode

ip cgmp

standby 1 ip 10.10.7.254

standby 1 priority 50

!

!

interface Vlan16

ip address 10.10.23.253 255.255.248.0

ip helper-address 10.10.16.29

no ip redirects

ip pim sparse-dense-mode

ip cgmp

standby 3 ip 10.10.23.254

standby 3 priority 200

standby 3 preempt

!

router eigrp 100

network 10.0.0.0

network 192.168.200.0

auto-summary

no eigrp log-neighbor-changes

!

!

ip pim rp-address 1.1.1.1 20

!

!

access-list 20 deny 224.0.1.39

access-list 20 deny 224.0.1.40

access-list 20 permit 224.0.0.0 15.255.255.255

ROUTER 1

-----------

!

ip multicast-routing

interface loopback 0

ip address 1.1.1.1 255.255.255.255

interface FastEthernet0/0

backup interface FastEthernet0/1

ip address 10.10.1.1 255.255.248.0

ip pim sparse-dense-mode

ip cgmp

!

interface Serial1/2

description "Connected to Bangalore"

bandwidth 2048

ip address 192.168.9.11 255.255.255.0

ip pim sparse-dense-mode

ip multicast rate-limit out 500

service-policy output browse

encapsulation ppp

ip route-cache flow

priority-group 2

down-when-looped

serial restart-delay 0

!

interface Serial1/3

description "Connected to Hyderabad"

bandwidth 2048

ip address 192.168.12.11 255.255.255.0

ip pim sparse-dense-mode

ip multicast rate-limit out 500

service-policy output browse

encapsulation ppp

ip route-cache flow

priority-group 2

down-when-looped

serial restart-delay 0

!

!

interface Serial2/2

description "Connected to Trivandrum"

bandwidth 2048

ip address 192.168.21.11 255.255.255.0

ip pim sparse-dense-mode

ip multicast rate-limit out 500

service-policy output browse

encapsulation ppp

ip route-cache flow

priority-group 2

down-when-looped

serial restart-delay 0

!

router eigrp 100

network 10.10.0.0 0.0.255.255

network 192.168.0.0 0.0.255.255

network 1.1.1.1 0.0.0.0

auto-summary

ip pim rp-address 1.1.1.1 20

!

access-list 20 deny 224.0.1.39

access-list 20 deny 224.0.1.40

access-list 20 permit 224.0.0.0 15.255.255.255

NOTE : THE ROUTER IS CONNECTED TO ----- SWITCH 1 ---------

REMOTE ROUTER 1

-----------------

!

ip multicast-routing

!

!

!

interface FastEthernet0/0

ip address 192.168.11.21 255.255.255.0

ip pim sparse-dense-mode

ip cgmp

interface Serial0/0

description "Connected to Chennai"

bandwidth 2048

ip address 192.168.12.12 255.255.255.0

ip pim sparse-dense-mode

ip multicast rate-limit out 500

service-policy output voice

encapsulation ppp

down-when-looped

!

!

router eigrp 100

network 192.168.0.0 0.0.255.255

auto-summary

!

ip pim rp-address 1.1.1.1 20

!

access-list 20 deny 224.0.1.39

access-list 20 deny 224.0.1.40

access-list 20 permit 224.0.0.0 15.255.255.255

[johnyoon75]

Could you please attach result from each routers using "show ip mroute" command?

Just in case, Why don't you try to confiure "ip pim sparse-dense mode" command into the loopback 0 interface?

I think that the loopback 0 interface is for Rp.

Right?

[a_mrk]

Thankyou friends.

We have more or less sorted out the problem.

The problem is due to the behaviour of the multicast. TO avoid flooding the network multicast

works in co-ordination with igmp and cgmp and prunes

the multicast from entering the segments where there

are no hosts for the multicast group active.

In our case as the router sits in VLAN 1 and there are hosts active in the multicast group the other side of the router (wan side) but the lan

side of the router does not recognise it and so multicast is forwarded to VLAN 1 only when a host joins the group in VLAN 1.

But we have found a way of making the multicast forwarded to VLAN 1 by either giving the

ip igmp join-group

either in the router f0/0 or in the VLAN 1 interface of the L3 switch.

this solved our problem

thankyou for the replies.

M.Radhakrishnan mrk@thehindu.co.in