Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
New Member

Multicast

1. On a mcast router that is failing RPF test, from source 10.0.0.0/24, is it safe to define an mcast default route like this

ip mroute 0.0.0.0 0.0.0.0 172.16.0.1 instead of the subnet route
ip mroute 10.0.0.0 255.0.0.0.0 172.16.0.1


2.How do I know when a router formely using RPT,had started using the SPT. Below is the output

R3(config)#do sh ip mro 230.0.0.1
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
Outgoing interface flags: H - Hardware switched, A - Assert winner
Timers: Uptime/Expires
Interface state: Interface, Next-Hop or VCD, State/Mode

(*, 230.0.0.1), 00:30:10/stopped, RP 2.2.2.2, flags: SJCL
  Incoming interface: FastEthernet0/0, RPF nbr 10.1.23.2, Mroute
  Outgoing interface list:
    Loopback0, Forward/Sparse, 00:21:07/00:02:27

(10.1.10.10, 230.0.0.1), 00:00:13/00:02:50, flags: LJT
  Incoming interface: FastEthernet0/0, RPF nbr 10.1.23.2, Mroute
  Outgoing interface list:
    Loopback0, Forward/Sparse, 00:00:13/00:02:46

1 REPLY
Cisco Employee

Re: Multicast

Hi,

1. On a mcast router that is failing RPF test, from source 10.0.0.0/24, is it safe to define an mcast default route like this

ip mroute 0.0.0.0 0.0.0.0 172.16.0.1 instead of the subnet route
ip mroute 10.0.0.0 255.0.0.0.0 172.16.0.1

You should not use a default static route unless you know all multicast traffic passing this router is only one direction; The direction of source tree and share tree might different; a default static route could cause problem. If you have to use static route, use more specific.

2.How do I know when a router formely using RPT,had started using the SPT. Below is the output

R3(config)#do sh ip mro 230.0.0.1
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
Outgoing interface flags: H - Hardware switched, A - Assert winner
Timers: Uptime/Expires
Interface state: Interface, Next-Hop or VCD, State/Mode

(*, 230.0.0.1), 00:30:10/stopped, RP 2.2.2.2, flags: SJCL
  Incoming interface: FastEthernet0/0, RPF nbr 10.1.23.2, Mroute
  Outgoing interface list:
    Loopback0, Forward/Sparse, 00:21:07/00:02:27

(10.1.10.10, 230.0.0.1), 00:00:13/00:02:50, flags: LJT
  Incoming interface: FastEthernet0/0, RPF nbr 10.1.23.2, Mroute
  Outgoing interface list:
    Loopback0, Forward/Sparse, 00:00:13/00:02:46

When the last hub router (the one connect to receiver) receive multicast exceed the threshold, it will start switchover process. On the lost hub router, the "J" flag on (*,G) entry indicate the switchover process.

HTH,

Lei Tian

695
Views
0
Helpful
1
Replies
CreatePlease to create content