Fore Systems ES-2810 - VLAN Explanation; Designated Management VLAN; IP Learning; Membership of Vlans

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FORE Systems ES-2810 Ethernet Switch User’s Manual
Concepts in Switching
A.9.3 VLAN Explanation
You can create separate VLANs by assigning port numbers of the switch, IP addresses of
devices, IP subnets and MAC addresses to a VLAN on the switch. This effectively “cuts” the
switch into completely independent segments. VLANs are useful for:
• Security issues. Groups can be isolated and the group traffic can be prevented
from being switched to other groups.
• Limiting Broadcast and Multicast traffic on the network to the specific VLAN.
• Resource allocation (departmental vs. common resources). Certain groups can be
allocated to specific resources, such as servers.
• Application specific reasons, for example to provide firewall protection.
If you have a network that is subnetted, you can configure the switch’s VLANs to match the
number of subnets you have created. You can then use routers to connect the subnets and pro-
vide filtering and firewall protection.
A.9.3.1 Membership of VLANs
It is important to note that a device can be a member of more than one VLAN. Any conflict in
membership between the VLANs can be checked using Stack View.
A.9.3.2 Designated Management VLAN
On the switch, there is always one VLAN that is designated to manage via SNMP. This VLAN
cannot be deleted unless another is selected as the Designated Management VLAN.
A.9.3.3 IP Learning
There are some ports you will only want to use the IP policy — not port or MAC address poli-
cies. This is called IP learning, and to ensure this happens the port can be selected to support
IP learning.