Networking Blog

A lot of dynamic routing protocols uses ip multicast for neighbor discovery, hellos and other things.
Here are some well known multicast adresses:

224.0.0.1 all hosts on a subnet
224.0.0.2 all routers on a subnet
224.0.0.4 Distance Vector Multicast Routing Protocols (DVMRP)
224.0.0.5 OSPF routers
224.0.0.6 OSPF designated routers
224.0.0.9 RIP Version 2 routers
224.0.0.10 EIGRP routers
224.0.0.13 Protocol independent Multicast (PIM) routers

Not so long ago, i hat to deal with IGMP, IP Multicast and Video on demand.
For test purposes it was necessary to change Windows XP’s default behaviour regarding the IGMP version used (WinXP uses IGMPv3 by default, i needed IGMPv2).
Perform the following registry change…

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters]
Add the DWORD IGMPVersion with a hex-Value of 3 (for IGMPv2) or [...]