Well-Known Or Reserved Multicast Addresses Excluded From Ip Multicast Filtering; Ip Multicast Filters - HP 2920 Series Multicast And Routing Manual

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 01/15/12 09:01:13 igmp:
DEFAULT_VLAN: Other Querier detected
I 01/15/12 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, 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 01/15/12 09:21:55 igmp: DEFAULT_VLAN:
Querier Election in process
I 01/15/12 09:22:00 igmp: DEFAULT_VLAN:
This switch has been elected as Querier
Well-known or reserved multicast addresses excluded 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.)
Table 2 lists the 32 well-known address groups (8192 total addresses) that IGMP does not filter
on.
Table 2 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
224.0.0.x
225.0.0.x
226.0.0.x
227.0.0.x
228.0.0.x
229.0.0.x
230.0.0.x
231.0.0.x
1
X is any value from 0 to 255.

IP multicast filters

NOTE: This operation applies to the HP Series 5400zl switches, the Series 3500yl switches, the
switch 6200yl, the switch 8212zl, the Series 5300xl switches, as well as the 1600M, 2400M,
2424M, 4000M, and 8000M, but not to the Series 2500, 2650, Series 4100gl, Series 4200vl,
or 6108 switches (which do not have static traffic/security filters.)
IP multicast addresses occur in the range from 224.0.0.0 through 239.255.255.255 (which
corresponds to the ethernet multicast address range of 01005e-000000 through 01005e-7fffff.)
Where a switch has a static traffic/security filter configured with a "multicast" filter type and a
24 Multimedia Traffic Control with IP Multicast (IGMP)
1
232.0.0.x
233.0.0.x
234.0.0.x
235.0.0.x
236.0.0.x
237.0.0.x
238.0.0.x
239.0.0.x
Groups of consecutive addresses in the range of 224.128.0.X
to 239.128.0.X
224.128.0.x
225.128.0.x
226.128.0.x
227.128.0.x
228.128.0.x
229.128.0.x
230.128.0.x
231.128.0.x
1
232.128.0.x
233.128.0.x
234.128.0.x
235.128.0.x
236.128.0.x
237.128.0.x
238.128.0.x
239.128.0.x