Netgear XCM8810 - 8800 SERIES 10-SLOT CHASSIS SWITCH ユーザーズマニュアル

VLAN Aggregation

This feature is supported only on the platforms listed for this feature 

in the license tables in 

.

VLAN aggregation is a feature aimed primarily at service providers. The purpose of VLAN 
aggregation is to increase the efficiency of IP address space usage. It does this by allowing 
clients within the same IP subnet to use different broadcast domains while still using the 
same default router. 

Using VLAN aggregation, a superVLAN is defined with the desired IP address. The 
subVLANs use the IP address of the superVLAN as the default router address. Groups of 
clients are then assigned to subVLANs that have no IP address, but are members of the 
superVLAN. In addition, clients can be informally allocated any valid IP addresses within the 
subnet. Optionally, you can prevent communication between subVLANs for isolation 
purposes. As a result, subVLANs can be quite small, but allow for growth without re-defining 
subnet boundaries.

Without using VLAN aggregation, each VLAN has a default router address, and you need to 
use large subnet masks. The result of this is more unused IP address space.

Multiple secondary IP addresses can be assigned to the superVLAN.

 illustrates VLAN aggregation.

EW_026

Sub-VLAN 1

Sub-VLAN 2

Sub-VLAN 3

Sub-VLAN n

Super VLAN_1

IP address: a.b.c.1

mask: /24

Sub-VLAN 1

Sub-VLAN 2

Sub-VLAN 3

Sub-VLAN n

Sub-VLAN 1

Sub-VLAN 2

Sub-VLAN 3

Sub-VLAN n

Super VLAN_2

IP address: a.b.d.1

mask: /24

OSPF Rtr_Link

VLAN_A

OSPF Rtr_Link

VLAN_B

Super VLAN_3

IP address: a.b.e.1

mask: /24