# Simple Multicast setup question



## Ender (Apr 26, 2012)

Simple setup, several freebsd FreeBSD 9 servers plugged into a switch. I just want to ping multicast between them. I was attempting to set up a simple multicast ntp on a large cluster of servers. https://lopsa.org/node/1480




```
app0# ifmcstat -i nfe0 -v
nfe0:
	inet 10.10.10.50
	igmpv3 flags=0<> rv 2 qi 125 qri 100 uri 3
		group 225.10.0.5 mode exclude
			mcast-macaddr 01:00:5e:0a:00:05
	link 00:e0:81:ba:f5:62
		group 01:00:5e:0a:00:05
	inet 10.10.10.50
	igmpv3 flags=0<> rv 2 qi 125 qri 100 uri 3
		group 224.0.0.1 mode exclude
			mcast-macaddr 01:00:5e:00:00:01
	link 00:e0:81:ba:f5:62
		group 01:00:5e:00:00:01
app0#
```



```
app1# ifmcstat -i nfe0 -v
nfe0:
	inet 10.10.10.51
	igmpv3 flags=0<> rv 2 qi 125 qri 100 uri 3
		group 225.10.0.5 mode exclude
			mcast-macaddr 01:00:5e:0a:00:05
	link 00:e0:81:ba:f4:c6
		group 01:00:5e:0a:00:05
	inet 10.10.10.51
	igmpv3 flags=0<> rv 2 qi 125 qri 100 uri 3
		group 224.0.0.1 mode exclude
			mcast-macaddr 01:00:5e:00:00:01
	link 00:e0:81:ba:f4:c6
		group 01:00:5e:00:00:01
app1# ping -T 10 -m 10 224.0.0.1
PING 224.0.0.1 (224.0.0.1): 56 data bytes
64 bytes from 10.10.0.101: icmp_seq=0 ttl=128 time=0.242 ms
64 bytes from 10.10.0.20: icmp_seq=0 ttl=64 time=0.738 ms (DUP!)
64 bytes from 10.10.0.21: icmp_seq=0 ttl=64 time=0.744 ms (DUP!)
64 bytes from 10.10.0.22: icmp_seq=0 ttl=64 time=0.747 ms (DUP!)
64 bytes from 10.10.0.23: icmp_seq=0 ttl=64 time=3.346 ms (DUP!)
64 bytes from 10.10.0.101: icmp_seq=1 ttl=128 time=0.266 ms
64 bytes from 10.10.0.21: icmp_seq=1 ttl=64 time=0.617 ms (DUP!)
64 bytes from 10.10.0.23: icmp_seq=1 ttl=64 time=0.681 ms (DUP!)
64 bytes from 10.10.0.20: icmp_seq=1 ttl=64 time=1.243 ms (DUP!)
64 bytes from 10.10.0.22: icmp_seq=1 ttl=64 time=3.569 ms (DUP!)
^C
```
10.10.0.20/21/22/23 and 101 are the Juniper ex4200 switches on the network. I have tried turning IGMP snooping on and off. I don*'*t feel the switches are related to the problem because the pings *I* am attempting are on the same switches. A.k.a. *I* am not even trying to span multicast across switches.

Also if *I* try to plug a crossover cable in between servers, *I* still get no multicast response. 

Any hints would be greatly appreciated. Over the last several days *I* have found documentation on this subject very lacking, that seems due to the idea that it should just work out of the box. All the documentation seems to be focused on multicast _routing_.


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