Huawei AR550 Series - Page 97

l Super-VLAN: It is different from the common VLAN. In the super-VLAN, only Layer 3
interfaces are created and physical ports are not contained. The super-VLAN can be viewed
as a logical Layer 3 concept. It is a collection of many sub-VLANs.
l Sub-VLAN: It is used to isolate broadcast domains. In the sub-VLAN, only physical ports
are contained and Layer 3 VLANIF interfaces cannot be created. The Layer 3 switching
with the external network is implemented through the Layer 3 interface of the super-VLAN.
A super-VLAN can contain one or more sub-VLANs retaining different broadcast domains. The
sub-VLAN does not occupy an independent subnet segment. In the same super-VLAN, IP
addresses of hosts belong to the subnet segment of the super-VLAN, regardless of the mapping
between hosts and sub-VLANs.
The same Layer 3 interface is shared by sub-VLANs. Some subnet IDs, default gateway
addresses of the subnets, and directed broadcast addresses of the subnets are saved and different
broadcast domains can use the addresses in the same subnet segment. As a result, subnet
differences are eliminated, addressing becomes flexible and idle addresses are reduced.
Take the Table 3-3 to explain the implementation theory. Suppose that user demands are
unchanged. In VLAN 2, 10 host addresses are demanded; in VLAN 3, 5 host addresses are
demanded; in VLAN 4, 1 host address is demanded.
According to the implementation of VLAN aggregation, create VLAN 10 and configure VLAN
10 as a super-VLAN. Then assign a subnet address 10.1.1.0/24 with the mask length being 24
to VLAN 10; 10.1.1.0 is the subnet ID and 10.1.1.1 is the gateway address of the subnet, as
shown in Figure 3-11. Address assignments of sub-VLANs (VLAN 2, VLAN 3, and VLAN 4)
are shown in Table 3-4.
Figure 3-11 Schematic diagram of VLAN aggregation
Sub VLAN 2
Host IP
10.1.1.2-10.1.1.11
VLAN 3
Sub VLAN 3
Host IP
10.1.1.12-10.1.1.16
Sub VLAN 4
Host IP
10.1.1.17
VLAN 4
VLAN 2
Super VLAN 10
VLANIF10:10.1.1.1/24
Huawei AR530&AR550 Series Industrial Switch Routers
Configuration Guide - Ethernet Switching
3 VLAN Configuration
Issue 01 (2014-11-30) Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
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