CTC Union GSW-3208M1, Руководство пользователя

Страница: 14 / 240

11
6. Manage / Configure the Switch
6.1 Introduction of the management functions
This switch is a L2 Management switch. It supports in -band management
function from Http/Telnet/SNMP interfaces. Console is supported for local
command-line settings. It supports network configuration functions, like
VLAN, Trunking, Port Mirror, QoS, spanning tree and software backup/update.
Users can configure these functions for di fferent network applications. The
following is a brief introduction about these functions before the detail operation
sections.
1. VLAN (Virtual LAN)
VLAN can divide the switch to several broadcast domains to prevent network
traffic between different user groups. This switch supports 802.1Q tag -
based VLAN and Port-based VLAN. Users with the same VLAN ID can
transfer data to each other. The network traffic will be blocked if they have
different VLAN ID. VLAN Stacking function for 802.1Q tag-based VLAN is
supported. It allows two VLAN tags in a packet for 802.1Q VLAN tunnelling
application through a central network.
2. Trunk
If two switches are cascaded together, the bottleneck will happen at the
cascading connection. If more cables could be used for the c ascading
connection, it will reduce the bottleneck problem. In normal case,
switches will become unstable because of traffic looping when more than
one cable is connected between them. If the switches support trunk
function, they can treat these cables as one connection between them. The
traffic looping will not happen between these cables and the switches will
work stable with bigger bandwidth between them.
Notes: About redundant application
The trunk connection supports redundant function. If any trunk cable is
broken, the traffic going through that cable will be transferred to another trunk
cable automatically. For example, if traffic of user port Port 6 is assigned to
Port 1 in a Trunk and Port 1 connection breaks, Port 2 will take over the traffic
for Port 6 automatically. (It could be used for redundant application.)
3. Spanning Tree Protocol / Rapid Spanning Tree Protocol
Spanning tree is a protocol to prevent network loop in network topology. If
network loop happens, it will cause switches in the network unstable
because more and more traffic will loop in the network. If network loop
happens, spanning tree protocol will block one connection in the loop