16-10
ATM Switch Router Software Configuration Guide
OL-7396-01
Chapter16 Configuring Tag Switching and MPLS
Configuring Tag Switching
Because a VP tunnel runs between switches, you must also configure a VP tunnel on the connecting
ATM interface on the destination switch. The examples that follow show how to configure VPtunnels
between switches.
Note The intermediate switch configuration follows in the next section, “Connecting the VP Tunnels.”
Figure 16-2 shows an example VP tunnel between a source switch and destination switch.
Figure16-2 Configuring VP Tunnels
Examples
In the following example, ATM interface0/1/1 on the source switch has no IP address and PVP 51 is
configured for IP unnumbered to loopback interface 0:
Switch(config-if)# interface atm 0/1/1
Switch(config-if)# atm pvp 51
Switch(config-if)# exit
Switch(config-if)# interface atm 0/1/1.51
Switch(config-subif)# ip unnumbered loopback 0
Switch(config-subif)# tag-switching ip
Switch(config-subif)# exit
In the following example, ATM interface0/1/3 on t he destination switch has no IP address and PVP 101
is configured for IP unnumbered to loopback interface 0:
Switch(config)# interface atm 0/1/3
Switch(config-if)# atm pvp 101
Switch(config-if)# exit
Switch(config)# interface atm 0/1/3.101
Switch(config-subif)# ip unnumbered loopback 0
Switch(config-subif)# tag-switching ip
Switch(config-subif)# exit
Step5 Switch(config-subif)# ip unnumbered type
number
or
Switch(config-subif)# ip address ip-address mask
Enables IP unnumbered on the ATM interface and
assigns the unnumbered interface to an interface
that has an IP address. We recommend enabling
IP unnumbered because it allows you to conserve
IP addresses and reduces the number of TVCs
terminating on the switch.
or
Assigns an IP address and subnet mask to the
ATM interface.
Step6 Switch(config-subif)# tag-switching ip Enables tag switching of IPv4 packets.
Command Purpose
0/1/1 0/1/3
Intermediate switch
PVP 51 PVP 101
Source switch Destination switch
S6807