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.)
The following table lists the 32 well-known address groups (8192 total addresses) that IGMP does not filter on.
Table 5: 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
1
Groups of consecutive addresses in the range of
224.128.0.X to 239.128.0.X
1
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
1
X
is any value from 0 to 255.
NOTE:
With aliasing limitation associated with MAC mode, certain non reserved multicast IP
addresses are displayed as "reserved" addresses.
For example: 225.0.0.x Multicast IP address is aliased to 224.0.0.x to be displayed as "reserved".
IP multicast 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 "multicast address" in this range, the switch will use the
static filter unless IGMP learns of a multicast group destination in this range. In this case, IGMP dynamically takes
over the filtering function for the multicast destination addresses for as long as the IGMP group is active. If the
IGMP group subsequently deactivates, the switch returns filtering control to the static filter.
40
Aruba 3810 / 5400R Multicast and Routing Guide for ArubaOS-
Switch 16.08
