HP ProCurve 2910al Switch User Manual

Multimedia Traffic Control with IP Multicast (IGMP)
Using the Switch as Querier
Using the Switch as Querier
The function of the IGMP Querier is to poll other IGMP-enabled devices in an
IGMP-enabled VLAN to elicit group membership information. The switch
performs this function if there is no other device in the VLAN, such as a
multicast router, to act as Querier. Although the switch automatically ceases
Querier operation in an IGMP-enabled VLAN if it detects another Querier on
the VLAN, you can also use the switch’s CLI to disable the Querier capability
for that VLAN.
Note A Querier is required for proper IGMP operation. For this reason, if you disable
the Querier function on a switch, ensure that there is an IGMP Querier (and,
preferably, a backup Querier) available on the same VLAN.
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 Querie
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
2-26

HP ProCurve 2910al Switch Specifications

General

Model	HP ProCurve 2910al Switch
Layer	Layer 3
Jumbo Frame Support	Yes
Power Device	Internal power supply
VLAN Support	Yes
Power Supply	100-240 VAC, 50/60 Hz
Ports	24 or 48 x 10/100/1000 ports
Uplink Ports	4 x SFP (mini-GBIC)
Stacking	Yes
MAC Address Table Size	32000 entries
Routing Protocol	RIP, OSPF, BGP, IGMP
Remote Management Protocol	SNMP 1, RMON 1, RMON 2, RMON 3, RMON 9, Telnet, SNMP 3, SNMP 2c, HTTP, TFTP
Features	VLAN, QoS, IPv6, ACLs
Compliant Standards	IEEE 802.3, IEEE 802.3u, IEEE 802.3ab, IEEE 802.3af
Operating Temperature	0 to 45°C
Operating Humidity	15% to 95% (noncondensing)
Power over Ethernet (PoE)	PoE+ (802.3at) on PoE+ models, PoE (802.3af) on PoE models