一.VLAN聚合由来
为了隔离广播域,一般会使用VLAN技术,VLAN的使用会导致每一个VLAN广播域都需要一个子网网段,每一个子网网段都有一个子网号,一个网关地址,一个子网广播地址无法使用,这会造成IP地址浪费。为了节省IP地址,从而产生了VLAN聚合技术。
二.VLAN聚合的描述
举个例子,在SW1交换机上创建了3个VLAN,分别是VLAN2,VLAN3,VLAN4。将VLAN4设定为super vlan,VLAN2和VLAN3设定为sub vlan。则在VLAN2和VLAN3使用同一子网的地址,VLAN4的VLANIF接口使用相同子网地址作为VLAN3和VLAN4的网关。
sub vlan相互之间是二层隔离的,默认无法互访,sub vlan内的网络设备将网关地址设置super vlan的VLANIF接口地址,通过该接口访问外部网络访问外部网络。
三.sub vlan访问外网的例子
SW2代码如下:
<SW2>display current-configuration
#
sysname SW2
#
vlan batch 2 to 4 10
#
cluster enable
ntdp enable
ndp enable
#
drop illegal-mac alarm
#
diffserv domain default
#
drop-profile default
#
vlan 4
aggregate-vlan
access-vlan 2 to 3
#
aaa
authentication-scheme default
authorization-scheme default
accounting-scheme default
domain default
domain default_admin
local-user admin password simple admin
local-user admin service-type http
#
interface Vlanif1
#
interface Vlanif4
ip address 10.1.1.254 255.255.255.0
#
interface Vlanif10
ip address 10.1.12.1 255.255.255.0
#
interface MEth0/0/1
#
interface GigabitEthernet0/0/1
port link-type access
port default vlan 2
#
interface GigabitEthernet0/0/2
port link-type trunk
port trunk allow-pass vlan 10
#
interface GigabitEthernet0/0/3
port link-type access
port default vlan 3
#
interface GigabitEthernet0/0/4
port link-type access
port default vlan 2
#
interface GigabitEthernet0/0/5
#
interface GigabitEthernet0/0/6
#
interface GigabitEthernet0/0/7
#
interface GigabitEthernet0/0/8
#
interface GigabitEthernet0/0/9
#
interface GigabitEthernet0/0/10
#
interface GigabitEthernet0/0/11
#
interface GigabitEthernet0/0/12
#
interface GigabitEthernet0/0/13
#
interface GigabitEthernet0/0/14
#
interface GigabitEthernet0/0/15
#
interface GigabitEthernet0/0/16
#
interface GigabitEthernet0/0/17
#
interface GigabitEthernet0/0/18
#
interface GigabitEthernet0/0/19
#
interface GigabitEthernet0/0/20
#
interface GigabitEthernet0/0/21
#
interface GigabitEthernet0/0/22
#
interface GigabitEthernet0/0/23
#
interface GigabitEthernet0/0/24
#
interface NULL0
#
ospf 1
area 0.0.0.0
network 10.1.1.0 0.0.0.255
network 10.1.12.0 0.0.0.255
#
user-interface con 0
user-interface vty 0 4
#
return
备注:如果要实现sub vlan之间的互访,只需要在super vlan的vlanif接口上输入:arp-proxy inter-sub-vlan-proxy enable