Each multicast host group is identified by a single IP address in the range 224.0.0.0 through 239.255.255.255. Specific groups of consecutive addresses in this range are “well-known” addresses and are reserved for predefined host groups. IGMP does not filter these addresses, so any packets the switch receives for such addresses are flooded out all ports assigned to the VLAN on which they were received (except the port on which the packets entered the VLAN).
The following table lists the 32 well-known address groups (8192 total addresses) that IGMP does not filter on the switches covered in this manual and on 1600M, 2400M, 2424M, 2650M, 4000M, 6108M, 8000M and switch 2500 series devices.
IP multicast address groups excluded from IGMP filtering
Groups of consecutive addresses in the range of 224.0.0.x to 239.0.0.x[a] | Groups of consecutive addresses in the range of 224.128.0.x to 239.128.0.x[a] | ||
---|---|---|---|
224.0.0.x | 232.0.0.x | 224.128.0.x | 232.128.0.x |
225.0.0.x | 233.0.0.x | 225.128.0.x | 233.128.0.x |
226.0.0.x | 234.0.0.x | 226.128.0.x | 234.128.0.x |
227.0.0.x | 235.0.0.x | 227.128.0.x | 235.128.0.x |
228.0.0.x | 236.0.0.x | 228.128.0.x | 236.128.0.x |
229.0.0.x | 237.0.0.x | 229.128.0.x | 237.128.0.x |
230.0.0.x | 238.0.0.x | 230.128.0.x | 238.128.0.x |
231.0.0.x | 239.0.0.x | 231.128.0.x | 239.128.0.x |
[a] x is any value from 0 to 255. |