NETGEAR GS716T User Manual

113
GS716T and GS724T Gigabit Smart Switches
IGMP Snooping
Internet Group Management Protocol (IGMP) Snooping is a feature that allows a switch to
forward multicast traffic intelligently on the switch. Multicast IP traffic is traffic that is destined
to a host group. Host groups are identified by class
D IP addresses, which range from
224.0.0.0 to 239.255.255.255. Based on the IGMP query and report messages, the switch
forwards traffic only to the ports that request the multicast traffic. This prevents the switch
from broadcasting the traffic to all ports and possibly affecting network performance.
A traditional Ethernet network may be separated into different network segments to prevent
placing too many devices onto the same shared media. Bridges and switches connect these
segments. When a packet with a broadcast or multicast destination address is received, the
switch will forward a copy into each of the remaining network segments in accordance with
the IEEE MAC Bridge standard. Eventually, the packet is made accessible to all nodes
connected to the network.
This approach works well for broadcast packets that are intended to be seen or processed by
all connected nodes. In the case of multicast packets, however, this approach could lead to
less efficient use of network bandwidth, particularly when the packet is intended for only a
small number of nodes. Packets will be flooded into network segments where no node has
any interest in receiving the packet. While nodes will rarely incur any processing overhead to
filter packets addressed to unrequested group addresses, they are unable to transmit new
packets onto the shared media for the period of time that the multicast packet is flooded. The
problem of wasting bandwidth is even worse when the LAN segment is not shared, for
example in full-duplex links.
Allowing switches to snoop IGMP packets is a creative effort to solve this problem. The
switch uses the information in the IGMP packets as they are being forwarded throughout the
network to determine which segments should receive packets directed to the group address.
The IGMP Snooping feature contains links to the following pages:
• IGMP Snooping Configuration on page 114
• IGMP Snooping Interface Configuration on page 115
• IGMP Snooping Table on page 117
• Multicast Forwarding Database Table on page 118
• MFDB Statistics on page 120
• IGMP Snooping VLAN Configuration on page 121
• Multicast Router Configuration on page 122
• Multicast Router VLAN Configuration on page 123

NETGEAR GS716T Specifications

General

Switch type	Managed
Switch layer	L3
Quality of Service (QoS) support	Yes
Stackable	-
Certification	CE, FCC, VCCI, EN, C-Tick, CCC, CSA, UL/cUL, IEC
Product color	Blue
LED indicators	Activity, Link, Power
SFP module slots quantity	2
Basic switching RJ-45 Ethernet ports type	Gigabit Ethernet (10/100/1000)
Basic switching RJ-45 Ethernet ports quantity	16
Number of VLANs	256
Networking standards	IEEE 802.1D, IEEE 802.1as, IEEE 802.1s, IEEE 802.1v, IEEE 802.3, IEEE 802.3ab, IEEE 802.3ad, IEEE 802.3i, IEEE 802.3u, IEEE 802.3x, IEEE 802.3z
Copper ethernet cabling technology	10BASE-T, 100BASE-TX, 100BASE-T, 1000BASE-T
Noise level	0 dB
Mean time between failures (MTBF)	567680 h
DHCP features	DHCP client
Security algorithms	802.1x RADIUS, HTTPS, SSL/TLS
AC input voltage	100 - 240 V
AC input frequency	50 - 60 Hz
Power consumption (typical)	14.4 W
MAC address table	16000 entries
Number of static routes	32
Operating altitude	0 - 3000 m
Storage temperature (T-T)	-20 - 70 °C
Operating temperature (T-T)	0 - 50 °C
Storage relative humidity (H-H)	0 - 95 %
Operating relative humidity (H-H)	0 - 90 %
Cables included	AC
Supported network protocols	IP

Weight and Dimensions

Depth	204 mm
Width	440 mm
Height	43 mm
Weight	2570 g