ā05-28-2025 01:50 AM
Hi all
I have old Cisco C6807-XL with an issue on multicast
just to resume fast.....basically:
interface Vlan2
ip vrf forwarding TEST
ip address 10.2.2.254 255.255.255.0
ip pim sparse-dense-mode
xconnect vfi VFI-2
interface Vlan1
ip vrf forwarding TEST
ip address 10.1.1.254 255.255.255.0
ip pim sparse-dense-mode
If my source multicast is in vlan 1 and client receiver in vlan 2 works but if the source is in vlan 2 dont.
xconnect block routing of PIM
is not possible to remove xconnect
someone can help me in a workaround?
Thanks
ā06-13-2025 07:52 AM
Hello man. As I can see, this is the most effective minimal configuration to solve your multicast issue while preserving your xconnect setup:
Essential Fix:
cisco
ip multicast-routing vrf TEST
!
interface Vlan1
ip pim sparse-dense-mode
ip igmp helper-address vrf TEST 10.2.2.254
!
interface Vlan2
ip pim sparse-dense-mode
ip igmp helper-address vrf TEST 10.1.1.254
Key Reasons:
Uses IGMP helper to bridge multicast across VLANs. It Maintains your existing xconnect configuration. Also, minimal impact to current operations
Verification:
cisco
show ip igmp groups vrf TEST
show ip mroute vrf TEST
Alternative If Still Not Working:
cisco
ip mroute vrf TEST 10.1.1.0 255.255.255.0 10.2.2.254
ip mroute vrf TEST 10.2.2.0 255.255.255.0 10.1.1.2544
This gives you two clean options to try - both designed to work around the xconnect limitation with minimal configuration changes. The first method (IGMP helper) is generally preferred as it's more standards-compliant.
If this solution doesn't work, ping me...
Hope this helps..
-Enes
ā06-20-2025 04:25 AM
Hi
thanks for your support
both solutions don't work
in helper address is not possible to configure vrf and command give me "Vlan2: Illegal helper address"
the second give me " %Inconsistent source and mask"
Thanks
Cesare
ā06-20-2025 07:48 AM
hello again, sad to see that it didnt work....
well well,,, Alrigth lets see. the xconnect command on Vlan2 creates a Virtual Forwarding Instance (VFI), which operates at Layer 2 and bypasses the IP routing layer where Protocol Independent Multicast (PIM) functions. This explains why multicast traffic flows correctly from Vlan1 (routed path) to Vlan2 but fails in the reverse direction.
now as i can see the solution that i said didnt work because one igmp helper approach,, which looks like the #ip igmp helper-address vrf test is not supported in this context. And the second one Statci mroute approach, again the problem is / with the command, which the correct format should specify the outgoing interface rather than the next-hop IP.
what i would try now is to COnfigure a loopback int as rendevous point rp
ip mroute vrf TESTt 10.1.1.0 255.255.255.0 Vlan1
ip mroute vrf TEST 10.2.2.0 255.255.255.0 Vvlan2
----
and the third option mvpn with bgp.
Now if nothing works again, let me know, and I will go ahead and do some EVEng labbing... and will get back to u...
hope it helps again...
-Enes
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