multicast routing over network borders

d-mark · ‎07-19-2007

Hello,

I'm searching for some hints on configuring multicast routing. Especially to get applications like apple's iChat (MDNS / 224.0.0.251) running over ip network borders. I have a catalyst 3560 with c3560-ipservices-mz.122-25.SED1.bin which should act as (multicast) router.

I have tried configuraions like:

ip multicast-routing distributed

!

interface Vlan1

ip address 192.168.1.1 255.255.255.0

ip pim [dense-mode | sparse-mode | sparse-dense-mode]

!

interface Vlan2

ip address 192.168.2.1 255.255.255.0

ip pim [dense-mode | sparse-mode | sparse-dense-mode]

!

[ip pim rp-address 192.168.1.1]

!

but without any success.

Could someone of you be so kind and give me a hint or point me in the right direction.

thanks in advance and kind regards

Mark

purohit_810 · ‎07-22-2007

Try by following two commands

ip pim accept-rp {address | auto-rp} [group-access-list-number]

ip pim message-interval seconds

Regards,

Dharmesh Purohit

d-mark · ‎07-23-2007

Thanks for your response. I tried the command

ip pim accept-rp {address | auto-rp} [group-access-list-number]

but without success. The onther command you mentioned isn't supported in the IOS version I use.

But I think I know now why mDNS (224.0.0.251) packets are not forewarded. At

http://www.iana.org/assignments/multicast-addresses

it is said that multicast datagrams with addresses within 224.0.0.0 to 224.0.0.255 should not be forwarded by multicast routers.

regards

Mark

machilfe.ch · ‎02-05-2011

I know its a very very long time since this thread was started.

I just sah the following on IANA.ORG.

Last Updated
2011-01-31
Note

    Host Extensions for IP Multicasting [RFC1112] specifies the extensions
    required of a host implementation of the Internet Protocol (IP) to
    support multicasting. The multicast addresses are in the range
    224.0.0.0 through 239.255.255.255. Address assignments are listed below.

    The range of addresses between 224.0.0.0 and 224.0.0.255, inclusive,
    is reserved for the use of routing protocols and other low-level
    topology discovery or maintenance protocols, such as gateway discovery
    and group membership reporting. Multicast routers should not forward
    any multicast datagram with destination addresses in this range,
    regardless of its TTL.

Regards