1 Topic by jvalenzuela

  • jvalenzuela
  • Initech programmer
  • Offline
  • From: Orlando, FL
  • Registered: 2007-10-10
  • Posts: 223

Topic: UDP multicasts

I'm running a ConMan on a dual homed host. One network connection is to communicate with NioNodes, the other is for native CAB control on the Cobranet work. I notice that when Conman is running, this host generates a lot of UDP multicasts, source <host IP>:4321 to 239.0.0.10:4321. Are these from the Conman process or from pandad? In either case, I don't think they are necessary on the Cobranet network. Is there a way to bind the generating process only to a specific interface?

2 Reply by michel

  • michel
  • michel
  • PDR Engineer
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  • From: Oxford, England
  • Registered: 2007-08-13
  • Posts: 31

Re: UDP multicasts

The UDP are for control communication between nions/conman; they are quite harmless on a network that hasn't anyone listening to them; in fact, they probably don't go much further than the first switch as nobody is listening to that multicast address on the network.
But to answer your question fully, no I don't think there is provision to bind to one specific interface for control communication.

3 Reply by jvalenzuela

  • jvalenzuela
  • Initech programmer
  • Offline
  • From: Orlando, FL
  • Registered: 2007-10-10
  • Posts: 223

Re: UDP multicasts

Unless your running some type of multicast registration system(IGMP or such), switches never learn multicast addresses and therefore forward them to all ports on the VLAN. Just because no one is listening, doesn't mean the switch isn't going to forward it.

I was hoping to eliminate this from the Cobranet network as it serves no purpose, is multicast in nature, and is relatively frequent. Especially since I am having problems with a n3's CM-1 crashing for unknown reasons. This is the only non-Cobranet traffic on that LAN excluding the extremely sparse Bootp and CDP frames. I like to keep that network rather 'clean'. It would be nice for a parameter in perhaps the pandad config file to bind it to a specific interface, but until then I guess I can use ingress filtering on the switch port in question.