I am wondering for the udp multicast to work, router must support it?
A:
Yes. In practice, multicast is still an intranet-only technology. http://www.multicasttech.com/status/
Nestor
2009-11-26 05:49:35
What i am concerned is I am building a distributed system and i want to use udp multicast to implement auto discovery, so i am afraid if the rounter doesn't support, my auto discovery may fail to work.
Benny
2009-11-26 06:18:07
A:
To be precise, you will need a multicast router if you want the traffic to traverse different subnets. Normally you can expect multicast to work fine on your local subnet.
Side note, many layer 2-3 switches do not include multicast routing functionality, they can however forward to an external multicast router. Multicast routing can be enabled in CISCO routers, etc.
Steve-o
2010-02-06 05:02:26
+1
A:
Multicast is based on dynamically generated trees that can (theoretically) span the entire internet. These multicast trees are based on two protocols:
- IGMP: Internet Group Management Protocol. Used by receivers and users like me and you.
- PIM: Protocol Independent Multicast. Used by routers to replicate and reroute the packets accordingly.
The client needs to be IGMP-compatible, and the routers need to be PIM-compatible.
David Titarenco
2010-02-06 05:09:00