interface tunnel
    Syntax
interface tunnelDescription
Creates or updates an IP tunnel. After you enter the command, the firmware switches to the configuration context for the tunnel.
If the specified tunnel exists, this command switches to the context for the tunnel.
By default, all tunnels are automatically assigned to the default VRF when they are created.
The没有form of this command deletes an existing IP tunnel.
Command context
config
Parameters
- 
        mode {gre ipv4 | ip 6in4 | ip 6in6}
- 
        Creates an IP tunnel. Choose one of the following options:- ip 6in4: Creates an IPv4 tunnel for IPv6 traffic.
- ip 6in6: Creates an IPv6 tunnel for IPv6 traffic.
 
- 
        
- 
        Specifies the number for a new tunnel. Range: 1 to 127. Numbering is shared between all tunnels, so the same tunnel number cannot be used for an IPv6 in IPv4 tunnel and a GRE tunnel. 
- 
        
- 
        Specifies the number for an existing IP tunnel. Range: 1 to 127. 
Command context
config-ip-if
Examples
       Defines a new IPv6 in IPv4 tunnel with number27.
      switch(config)#interface tunnel 27 mode ip 6in4switch(config-ip-if)#
       Switches to the
      config-ip-ifcontext for existing tunnel27.switch(config)#interface tunnel 27switch(config-ip-if)#
       DeletesIPv6在IPv4 tunnel27.
      switch(config)#没有interface tunnel 27
       Defines a new IPv6 in IPv6 tunnel with number8.
     switch(config)#接口ip 6 in6隧道8模式switch(config-ip-if)#