Dell Networking 7048 Configuration Manual page 1170

Using DVMRP as the Multicast Routing Protocol
DVMRP is used to communicate multicast information between L3 switches
or routers. If a PowerConnect 7000 Series switch handles inter-VLAN routing
for IP traffic, including IP multicast traffic, multicast routing might be
required on the switch.
DVMRP is best suited for small networks where the majority of hosts request
a given multicast traffic stream. DVMRP is similar to PIM-DM in that it
floods multicast packets throughout the network and prunes branches where
the multicast traffic is not desired. DVMRP was developed before PIM-DM,
and it has several limitations that do not exist with PIM-DM.
You might use DVMRP as the multicast routing protocol if it has already been
widely deployed within the network.
Microsoft Network Load Balancing
PowerConnect switches support Microsoft Network Load Balancing (NLB) in
unicast mode only. When using Microsoft NLB, ensure that the Cluster
Operation Mode is configured to the default value of Unicast.
1170
Managing IPv4 and IPv6 Multicast