[c-nsp] MSDP and my limited knowledge question

[Phil Mayers]

On 09/03/2012 07:12 PM, Mihai Tanasescu wrote:

> b) if I put:
> 10.10.10.1/29 or /32 configured on S on a Loopback interface
> and on C4900:
> ip route 10.10.10.0 255.255.255.240 192.168.1.2

So, to be clear, you're doing this i.e. trying to source the multicast 
from a "virtual" IP:

Linux:

ip addr add 192.168.1.2/24 dev eth0
ip addr add 10.10.10.1/23 dev lo
send-multicast --source 10.10.10.1 --group 233.x.x.x

Cisco:

int Vlan123
   ip address 192.168.1.1 255.255.255.0
   ip pim sparse-mode
ip route 10.10.10.1 255.255.255.255 192.168.1.2

I don't think this will work. The c4900 isn't a PIM DF for 10.10.10.1, 
so won't send PIM register packets (or MSDP advertisments).

You could try adding the 10-net as a "secondary"

int Vlan123
   ip address 192.168.1.1 255.255.255.0
   ip address 10.10.10.2 255.255.255.248 secondary
   ip pim sparse-mode

Linux by default will respond to ARP packets for any of its IPs on all 
interfaces, so this should in theory work.

Another alternative is the "proxy-register" argument, but that's only 
available in dense mode:

   ip pim dense-mode proxy-register [list x | route-map y]

I wonder if the multicast stub-routing functionality will trick the 4900 
into being the DF?

Otherwise, you'll have to run a PIM SM routing protocol on the Linux 
box, and trust me - you don't want to do that.