User guide

11-12 E
XTREME
W
ARE
S
OFTWARE
U
SER
G
UIDE
IP U
NICAST
R
OUTING
As a result, sub-VLANs 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 super-VLAN. These IP
addresses are only used to respond to ICMP ping packets to verify connectivity.
Figure 11-2 illustrates VLAN aggregation.
Figure 11-2: VLAN aggregation
In Figure 11-2, all stations are configured to use the address 10.3.2.1 for the default
router.
1234AB5678
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
Super VLAN_2
IP address: a.b.d.1
mask: /24
Sub-VLAN 1 Sub-VLAN 2 Sub-VLAN 3 Sub-VLAN n
Super VLAN_3
IP address: a.b.e.1
mask: /24
OSPF Rtr_Link
VLAN_A
OSPF Rtr_Link
VLAN_B