This topic is to discuss the following lesson:
I setup up lab for 4 routers to allow one router and block other router, it’s not working, but for two routers like your lab its working.
in this LAB I want to filter R1 as source to R4 which is configured group address 239.9.9…9, but its allowing all sources.
R1 interface GigabitEthernet1/0 ip address 18.104.22.168 255.255.255.0 ip pim sparse-mode negotiation auto end ! ip pim rp-add 22.214.171.124
interface GigabitEthernet1/0 ip address 126.96.36.199 255.255.255.0 ip pim sparse-mode negotiation auto ! interface GigabitEthernet2/0 ip address 188.8.131.52 255.255.255.0 ip pim sparse-mode negotiation auto ! interface FastEthernet0/0 ip address 184.108.40.206 255.255.255.0 ip pim sparse-mode duplex half ! ip pim rp-address 220.127.116.11 ip pim accept-register list Source ! interface Loopback0 ip address 18.104.22.168 255.255.255.255 ip pim sparse-mode ! ip access-list extended Source deny ip host 22.214.171.124 host 126.96.36.199 permit ip any any
I setup same LAB in VIRL, the previous LAB was GNS3, right now its showing this debug message
Aug 22 05:13:25.023: %PIM-4-INVALID_SRC_REG: Received Register from 188.8.131.52 for (184.108.40.206, 220.127.116.11), not willing to be RP
from R2 (Which is the RP), but even though I’m receiing INVALID-Source address its still allowing to ping the group address and even setting up in multicast routing.
(18.104.22.168, 22.214.171.124), 00:02:26/00:00:33, flags: FT Incoming interface: GigabitEthernet0/1, RPF nbr 126.96.36.199 Outgoing interface list: GigabitEthernet0/2, Forward/Sparse, 00:02:26/00:02:04
I changed topology this way its working without Issue
Why its accepting R1 as source and not accepting Source Router as Source ?
the difference between the Source router and R1 is that the Source router isn’t running any PIM mode, I just enabled ip multicast-routing. (and sure I modified the Access-list)
is this means that if the DR it self generates multicast traffic as source, the Pim Accept Register will not effect it?.
It’s probably because the pings are sent from the G1/0 interface on the R1 router. When R2 doesn’t accept 188.8.131.52 as a source, it sends a prune message to R1 so that it doesn’t forward this multicast traffic anymore. R1 however, is sourcing the traffic from its G1/0 interface so it’s not “multicast routed”.
If you source the multicast traffic from a loopback interface on R1 that isn’t permitted on the access-list of R2, you’ll see that R1 no longer forwards it on its G1/0 interface because of the pruning.