IBM SC41-5420-04 manual CHGLINTRN LINDTRNLINE FCNADRC00000040000

supported on multi-access nonbroadcast networks. IP multicast is also not currently supported on Frame Relay, FDDI/SDDI, or ATM networks. To determine whether an interface supports multicast, enter option 14 on the Work with TCP/IP Interface Status display. If the interface supports multicast, there will be at least one Host Group entry for the All Hosts group 224.0.0.1. Otherwise, the interface does not support multicast.

The 2626 token-ring input-output processor (IOP) requires manual configuration to receive multicast datagrams. In particular, you must specify the token-ring address, C00000040000, on the functional address parameter for the token-ring line description. To add this address to a line description that is named TRNLINE, use the following command:

CHGLINTRN LIND(TRNLINE) FCNADR(C00000040000)

The 2617 Ethernet IOP also requires manual configuration in order to receive multicast datagrams. The Ethernet group addresses to be received need to be specified on the group address parameter (GRPADR) for the Ethernet line description. A 4-byte IP multicast address is mapped to a 6-byte Ethernet group address by placing the low-order 23 bits of the IP multicast address into the low-order 23 bits of the Ethernet group address 01005E000000. For example, to receive multicast datagrams with a destination address of 224.255.0.2, the GRPADR parameter for the 2617 Ethernet line description must include 01005E7F0002.

Chapter 2. TCP/IP: Operation, Management, and Advanced Topics 69