Coyote Point Systems E350GX, Руководство по установке и администрированию

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Configuring VLANs on Equalizer
Equalizer Installation and Administration Guide 65
A number of methods can be used to mitigate problems and threats associated with large broadcast domains,
including broadcast filtering and physically separating large broadcast domains into smaller domains. The problem
with these solutions is that the are typically implemented at the Network Layer (Layer 3), and require Layer 3
devices (such as routers and firewalls) to implement them. These Layer 3 devices require separate subnets, and
themselves emit a significant amount of broadcast traffic.
What we really want is a way of abstracting the idea of a LAN so that large broadcast domains can be separated into
smaller domains
without requiring any network rewiring or physical movement of systems . We’d also like the ability
to extend broadcast domains across Layer 3 devices to physically remote systems.
With a VLAN, the broadcast domain for a particular system is determined by the software settings on the Layer 2
switch port to which the system is connected .
So, for example, in a traditional LAN, all the systems connected to Switch A would be part of Broadcast Domain A.
If the switch is a VLAN-capable switch, then it is possible to configure several ports on the switch for VLAN A,
several others to VLAN B, others to VLAN C, and so on.
This allows you to both:
• reduce the number of devices in local broadcast domains
• extend broadcast domains across devices separated by more than one switch
The predominant VLAN standard is 802.1q. This standard adds a VLAN tag to the information in the Ethernet
packet. Since they operate at the switching level, VLANs are Layer 2 technologies -- though they are often confused
with Layer 3 subnetting, because in many configurations there is one VLAN configured per subnet. This is usually
done for the practical purpose of allowing the systems on a VLAN to be managed as a group by other network
management devices/software that work by IP address ranges, for example, rather than VLAN tags.
Configuring VLANs on Equalizer
Configured VLANs are listed on the
VLAN Configuration
tab. To open it, click on the Equalizer system name in the
left frame and click on the
Networking
tab in the right frame:
The following information is shown for each VLAN:
Name
The VLAN name.
VID
The VLAN ID, an integer between 1 and 4095.
Contents
Icons in this column indicate whether the VLAN hosts clusters ( ), servers
( ) or both.
Tagged Ports
The port numbers of the Tagged ports assigned to this VLAN. Tagged ports
can be assigned to more than one VLAN.