Troubleshooting guide

3. Troubleshooting Functional Failures During Operation
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3.9.6 Problems that occur during IPv4 multicast communication in the
extranet
To resolve problems on IPv4 multicast communication in an extranet, first, try to use the check
items described in 3.9.5 IPv4 multicast communication problems in VRF and make sure that
multicast communication is possible in each VRF. After that, check the following.
Table 3-34: Items to check for an extranet
3.9.7 Communication is not possible on the IPv4 PIM-DM networks
If multicast forwarding is not possible in an IPv4 PIM-DM network configuration, isolate the cause
of the problem according to the failure analysis method described below.
The following figure shows an example of an IPv4 PIM-DM network.
No. Items to check and commands Action
1 Make sure that the unicast route from the destination
VRF to the source address is the expected VRF or
global network.
show ip rpf
If it is not the case, check the settings of the unicast
extranet.
2 Make sure that the protocol (PIM-SM or PIM-SSM)
for the IPv4 multicast address used in the extranet is
the same between the destination VRF and the
upstream VRF.
show running-config
If the protocol is different between the destination VRF
and the upstream VRF, select a suitable IPv4 multicast
address so that the protocol can be the same between them.
3 For the upstream VRF, check whether the unicast
route to the source address is not another VRF.
show ip rpf
Configure the upstream VRF so that the unicast route to
the source address is a VRF with an actual interface in the
VRF.
4 If the PIM-SM VRF gateway is used, make sure that
(
*,G) entries have been generated in the upstream
VRF. Also, make sure that
V is displayed for Flags
for the target (*,G) entry.
show ip mroute
If (*,G) entries are not generated correctly, make sure that
the IPv4 multicast address used in extranet communication
has been specified as the host address and permitted for the
IPv4 multicast route filtering for the upstream VRF.
5 If the PIM-SM VRF gateway is used, make sure that
the destination VRF is displayed for the downstream
interface for the (
*,G) entry generated in the
upstream VRF.
show ip mroute
If the destination VRF does not exist in the downstream
interface for the (
*,G) entry of the upstream VRF, make
sure that the destination VRF has been permitted for
route-map that specifies the host address for IPv4
multicast route filtering in the upstream VRF.
If no specific VRF is specified for route-map by the
match
vrf command, every VRF is permitted to be a destination.
6 If
(denied) is displayed for the VRF of the
upstream interface by the show ip mroute
command, IPv4 multicast route filtering for the
upstream VRF has not been set correctly. If the route
does not exist, check the IPv4 multicast route
filtering of the upstream VRF in the configuration.
show ip mroute
show running-config
Make sure that the IPv4 multicast address and destination
VRF that are used in extranet communication have been
permitted for the IPv4 multicast route filtering for the
upstream VRF.
If neither specific IPv4 multicast address nor specific VRF
is specified for the IPv4 multicast route filtering, all IPv4
multicast addresses and VRFs are permitted.