在 Catalyst 2900XL/3500XL/2950 交换机上使用外部路由器配置 VLAN 间路由和 ISL/802.1Q 中继

Note: 以下屏幕获取显示在3512XL交换机被输入的命令。在命令之间的备注是解释某些命令和步骤的用蓝色被添加的斜体字。

!-- Set the privileged mode


!-- and Telnet password on the switch.

switch#configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
switch(config)#hostname 3512xl
3512xl(config)#enable password mysecret
3512xl(config)#line vty 0 4
3512xl(config-line)#login
3512xl(config-line)#password mysecret
3512xl(config-line)#exit
3512xl(config)#no logging console
3512xl(config)#^Z


!-- Set the IP address and default gateway for VLAN1 for management purposes.

3512xl#configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
3512xl(config)#int vlan 1
3512xl(config-if)#ip address 10.10.10.2 255.255.255.0
3512xl(config-if)#exit
3512xl(config)#ip default-gateway 10.10.10.1
3512xl(config)#end

!-- Set the VTP Mode. !-- In our example, we have set the mode to be transparent. !-- Depending on your network, set the VTP Mode accordingly. !-- For details on VTP, !-- refer to !-- Creating and Maintaining VLANs on Catalyst 2900XL and 3500XL Switches.

3512xl#vlan database
3512xl(vlan)#vtp transparent
Setting device to VTP TRANSPARENT mode.


!-- Adding VLAN2. VLAN1 already exists by default.

3512xl(vlan)#vlan 2
VLAN 2 added:
Name: VLAN0002
3512xl(vlan)#exit
APPLY completed.
Exiting....


!-- Enable trunking on the interface fastEthernet 0/1.

3512xl#configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
3512xl(config)#int fastEthernet 0/1
3512xl(config-if)#switchport mode trunk


!-- Enter the trunking encapsulation as either isl

3512xl(config-if)#switchport trunk encapsulation isl

!-- or as dot1q:


3512xl(config-if)#switchport trunk encapsulation dot1q

!-- In case of 2940/2950 series switches, none of the above two commands are used, !-- 2940/2950 series switches only support 802.1q encapsulation which is configured automatically, !-- when trunking is enabled on the interface by using switchport mode trunk command. !-- In case of dot1q, you need to make sure that !-- the native VLAN matches across the link. !-- On 3512XL, by default, the native VLAN is 1. !-- Depending on your network needs, you may change !-- the native VLAN to be other than VLAN1, !-- but it is very important that you change the native VLAN !-- on the router accordingly. !-- You may change the native VLAN, if needed, by using the following command: !-- 3512xl(config-if)#switchport trunk native vlan <vlan ID> !-- Allow all VLANs on the trunk.

3512xl(config-if)#switchport trunk allowed vlan all
3512xl(config-if)#exit


!-- The following set of commands will place FastEthernet 0/2 !-- into VLAN2 and enable portfast on the interface.

3512xl(config)#int fastEthernet 0/2
3512xl(config-if)#switchport access vlan 2
3512xl(config-if)#spanning-tree portfast
3512xl(config-if)#exit


!-- FastEthernet 0/3 is already in VLAN1 by default. !-- Enable portfast on the interface.

3512xl(config)#int fastEthernet 0/3
3512xl(config-if)#spanning-tree portfast
3512xl(config-if)#^Z

!-- For details on why to enable portfast, !-- refer to: !-- Using PortFast and Other Commands to Fix Workstation Startup Connectivity Delays. !-- Remember to save the configuration.

3512xl#write memory
Building configuration...

3512xl#

--------------------------------------------------------------------------------

3512xl#show running-config
Building configuration...

Current configuration:

!
version 12.0
no service pad
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname 3512xl
!
no logging console
enable password mysecret
!
!
!
!
!
ip subnet-zero
!
!
!
interface FastEthernet0/1
  switchport mode trunk
!

!-- If 802.1Q is configured, !-- you will instead see the following output !-- under interface FastEthernet0/1: !-- interface FastEthernet0/1 !-- switchport trunk encapsulation dot1q !-- switchport mode trunk

!
interface FastEthernet0/2
 switchport access vlan 2
 spanning-tree portfast
!
interface FastEthernet0/3
 spanning-tree portfast
!
interface FastEthernet0/4
!
interface FastEthernet0/5
!
interface FastEthernet0/6
!
interface FastEthernet0/7
!
interface FastEthernet0/8
!
interface FastEthernet0/9
!
interface FastEthernet0/10
!
interface FastEthernet0/11
!
interface FastEthernet0/12
!
interface GigabitEthernet0/1
!
interface GigabitEthernet0/2
!
interface VLAN1
 ip address 10.10.10.2 255.255.255.0
 no ip directed-broadcast
 no ip route-cache
!
ip default-gateway 10.10.10.1
!
line con 0
 transport input none
 stopbits 1
line vty 0 4
 password mysecret
 login
line vty 5 15
 login
!
end

Note: 以下屏幕获取显示在Cisco 2600路由器被输入的命令。在命令之间的备注是解释某些命令和步骤的用蓝色被添加的斜体字。

!-- Set the privileged mode !-- and Telnet password on the router.

Router#configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Router(config)#hostname c2600

c2600(config)#enable password mysecret
c2600(config)#line vty 0 4
c2600(config-line)#login
c2600(config-line)#password mysecret
c2600(config-line)#exit
c2600(config)#no logging console
c2600(config)#^Z

c2600#configure terminal
Enter configuration commands, one per line. End with CNTL/Z.


!-- Select FastEthernet 0/0 for the trunk configuration. !-- No L2 or Layer 3 (L3) configuration is done here.

c2600(config)#int fastEthernet 0/0
c2600(config-if)#no shut
c2600(config-if)#exit


!-- Enable trunking on the sub-interface FastEthernet 0/0.1. !-- Note that actual trunks are configured on the sub-interfaces.

c2600(config)#int fastEthernet 0/0.1


!-- Enter the trunking encapsulation as either isl 
c2600(config-subif)#encapsulation isl 1


!-- or as dot1q: !-- In case of dot1q, you need to make sure that !-- the native VLAN matches across the link. !-- On 3512XL, by default, the native VLAN is 1. !-- On the router, configure VLAN1 as the native VLAN.

c2600(config-subif)#encapsulation dot1Q 1 ?
  native  Make this is native vlan
  <cr>
c2600(config-subif)#encapsulation dot1Q 1 native

!-- On the switch, if you have a native VLAN other than VLAN1, !-- on the router, configure the same VLAN to be the native VLAN, !-- by using the above command.

Note: encapsulation dot1Q 1 native命令在Cisco IOS版本12.1(3)T被添加了。如果使用一更早的Cisco IOS版本，早于12.1(3)T本文的部分请参见Cisco IOS版本的802.1Q配置配置在路由器的802.1q中继。

!-- Configure L3 information on the sub-interface 0/0.1.

c2600(config-subif)#ip address 10.10.10.1 255.255.255.0
c2600(config-subif)#exit


!-- Enable trunking on the sub-interface FastEthernet 0/0.2. !-- Note that actual trunks are configured on the sub-interfaces.

c2600(config)#int fastEthernet 0/0.2


!-- Enter the trunking encapsulation as either isl

c2600(config-subif)#encapsulation isl 2


!-- or as dot1q:

c2600(config-subif)#encapsulation dot1Q 2


!-- Configure L3 information on the sub-interface 0/0.2.

c2600(config-subif)#ip address 10.10.11.1 255.255.255.0
c2600(config-subif)#exit
c2600(config)#^Z


!-- Remember to save the configuration.

c2600#write memory
Building configuration...
[OK]
c2600#

Note: 为了做此设置工作和顺利连接在workstation1和workstation2之间，您需要确信，在工作站的默认网关适当地设置。对于workstation1，默认网关应该是10.10.11.1，并且为workstation2，默认网关应该是10.10.10.1。关于关于怎样的详细资料设置在工作站的默认网关，请参见他们的在本文的相应的章节。

Note: 如果配置了在路由器和交换机之间的802.1q中继以下段只是可适用的。

Note: 如果遵从在上述部分列出的配置步骤，并且仍然不能在VLAN间连接(在workstation1和workstation2之间)，则有您遇到了警告CSCds42715， 802.1Q本地VLAN关键字不正常运行的可能性，当快速的交换是启用的时。Bug修正在以下代码版本集成：12.2(0.5)， 12.2(0.5)T， 12.1(5)DC， 12.1(5)YB， 12.2(0.18)S， 12.1(5)YD02， 12.2(2)B， 12.2(15)ZN。您能检查状况和Bug的简要描述通过使用Bug Toolkit (仅限注册用户)和输入Bug ID CSCds42715。

--------------------------------------------------------------------------------

c2600#show running-config
Building configuration...
 
Current configuration:
!
version 12.1
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname c2600
!
no logging console
enable password mysecret
!
!
!
!
!
ip subnet-zero
!
!
!
!
!
!
!
!
!
!
interface FastEthernet0/0
 no ip address
 duplex auto
 speed auto
!
interface FastEthernet0/0.1
 encapsulation isl 1
 ip address 10.10.10.1 255.255.255.0
 no ip redirects
!

!-- If 802.1Q is configured, !-- you will instead see the following output !-- under interface FastEthernet0/0.1: !-- interface FastEthernet0/0.1 !-- encapsulation dot1Q 1 native !-- ip address 10.10.10.1 255.255.255.0

!
!
interface FastEthernet0/0.2
 encapsulation isl 2
 ip address 10.10.11.1 255.255.255.0
 no ip redirects
!

!-- If 802.1Q is configured, !-- you will instead see the following output !-- under interface FastEthernet0/0.2: !-- interface FastEthernet0/0.2 !-- encapsulation dot1Q 2 !-- ip address 10.10.11.1 255.255.255.0

!
interface FastEthernet0/1
 no ip address
 shutdown
 duplex auto
 speed auto
!
ip classless
no ip http server
!
!
!
line con 0
 transport input none
line aux 0
line vty 0 4
 password mysecret
 login
!
no scheduler allocate
end

!-- Set the privileged mode !-- and Telnet password on the router.

Router#configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Router(config)#hostname c2600
c2600(config)#enable password mysecret
c2600(config)#line vty 0 4
c2600(config-line)#login;
c2600(config-line)#password mysecret
c2600(config-line)#exit
c2600(config)#no logging console
c2600(config)#^Z

c2600#configure terminal
Enter configuration commands, one per line. End with CNTL/Z.


!-- Select FastEthernet 0/0 for the trunk configuration.

c2600(config)#int fastEthernet 0/0
c2600(config-if)#no shut


!-- Note that the IP address for VLAN1 is configured on the main interface, !-- and no encapsulation for VLAN1 will be done under the sub-interface.

c2600(config-if)#ip address 10.10.10.1 255.255.255.0
c2600(config-if)#exit


!-- Configure dot1q encapsulation for VLAN 2 !-- on sub-interface fastEthernet 0/0.2.

c2600(config)#int fastEthernet 0/0.2
c2600(config-subif)#encapsulation dot1Q 2
c2600(config-subif)#


!-- Configuring L3 information on the sub-interface 0/0.2.

c2600(config-subif)#ip address 10.10.11.1 255.255.255.0
c2600(config-subif)#exit
c2600(config)#^Z


!-- Remember to save the configuration.

c2600#write memory
Building configuration...
[OK]
c2600#

Note: 为了做此设置工作和顺利连接在workstation1和workstation2之间，您需要确信，在工作站的默认网关适当地设置。对于workstation1，默认网关应该是10.10.11.1，并且为workstation2，默认网关应该是10.10.10.1。关于关于怎样的详细资料设置在工作站的默认网关，请参见在本文的thei相应的章节。

c2600#show running-config
Building configuration...

Current configuration:
!
version 12.1
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
!
hostname c2600
!
no logging console
enable password mysecret
!
!
!
!
!
memory-size iomem 7
ip subnet-zero
!
!
!
!
!
!
!
interface FastEthernet0/0
 ip address 10.10.10.1 255.255.255.0
 duplex auto
 speed auto
!
interface FastEthernet0/0.2
 encapsulation dot1Q 2
 ip address 10.10.11.1 255.255.255.0
!
interface FastEthernet0/1
 no ip address
 shutdown
 duplex auto
 speed auto
!
ip classless
no ip http server
!
!
line con 0
 transport input none
line aux 0
line vty 0 4
 password mysecret
 login
!
no scheduler allocate
end

c2600#