Signamax Managed Hardened PoE Industrial DIN-rail Mount Switch - Manual (Page 22)

5 VLAN
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5 VLAN
The traditional Ethernet is a broadcast network, where all hosts are in the same broadcast
domain and connected with each other through hubs or switches. The hub is a physical layer
device without the switching function, so it forwards the received packet to all ports. The
switch is a link layer device which can forward the packet according to the MAC address of
the packet. However, when the switch receives a broadcast packet or an unknown unicast
packet whose MAC address is not included in the MAC address table of the switch, it will
forward the packet to all the ports except the inbound port of the packet. In this case, a host in
the network receives a lot of packets whose destination is not the host itself. Thus, plenty of
bandwidth resources are wasted, causing potential serious security problems.
The traditional way to isolate broadcast domains is to use routers. However, routers are
expensive and provide few ports, so they cannot subnet the network particularly.
The virtual local area network (VLAN) technology is developed for switches to control
broadcast in LANs.
By creating VLANs in a physical LAN, you can divide the LAN into multiple logical LANs, each
of which has a broadcast domain of its own. Hosts in the same VLAN communicate with each
other as if they are in a LAN. However, hosts in different VLANs cannot communicate with
each other directly.
This managed switch supports 802.1Q VLAN and port-based VLAN. VLAN is in 802.1Q mode
in default configuration.
5.1 Advanced
This page globally sets the VLAN mode from the following: NO VLAN, port-based VLAN and