ProCurve Series 2300 and 2500 Switches Release Notes

227
Enhancements in Release F.02.02
The Switch Excludes Well-Known or Reserved Multicast Addresses from IP Multicast Filtering
If the switch becomes the Querier for a particular VLAN (for example, the DEFAULT_VLAN), then
subsequently detects queries transmitted from another device on the same VLAN, the switch ceases
to operate as the Querier for that VLAN. If this occurs, the switch Event Log lists a pair of messages
similar to these:
I 01/15/01 09:01:13 igmp: DEFAULT_VLAN: Other Querier detected
I 01/15/01 09:01:13 igmp: DEFAULT_VLAN: This switch is no longer Querier
In the above scenario, if the other device ceases to operate as a Querier on the default VLAN, then
the switch detects this change and can become the Querier as long as it is not pre-empted by some
other IGMP Querier on the VLAN. In this case, the switch Event Log lists messages similar to the
following to indicate that the switch has become the Querier on the VLAN:
I 01/15/01 09:21:55 igmp: DEFAULT_VLAN: Querier Election in process
I 01/15/01 09:22:00 igmp: DEFAULT_VLAN: This switch has been elected as
Querier
The Switch Excludes Well-Known or Reserved Multicast
Addresses from IP Multicast Filtering
Each multicast host group is identified by a single IP address in the range of 224.0.0.0 through
239.255.255.255. Specific groups of consecutive addresses in this range are termed "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
Series 2500 switches.
Table 19. Well-Known 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*
Groups of Consecutive
Addresses in the Range of
224.128.0.X to 239.128.0.X*
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