The NAS-Port-ID Format C Enhancement feature provides the following broadband subscriber access line identification (NAS-Port-ID) coding format:

{atm/eth/trunk} NAS_slot/NAS_subslot/NAS_port:XPI:XCI {Circuit-ID/Remote-ID/default string}

• For ATM, XPI is the virtual path identifier (VPI) and XCI is the virtual circuit identifier (VCI).
• For Ethernet, XPI is outer vlan-tag, XCI is inner vlan-tag.
• Requirements for XPI:XCI for Ethernet are as follows:
  • For 802.1Q tunneling (QinQ), the format should be outer vlan-tag:inner vlan-tag. (Prior to Release 12.2(31)SB2, Cisco IOS software supports inner vlan-tag:outer vlan-tag).
  • For single tag VLAN, XPI should be 4096.
• The Circuit-ID tag (if present) must be appended to this string when the nas-port-id format c command is used. The format for the Circuit-ID or Remote-ID tag is as follows:

AccessNodeIdentifier/ANI_rack/ANI_frame/ANI_slot/ANI_subslot/ANI_port[:ANI_XPI.ANI_XCI]

• The digital subscriber line access multiplexer (DSLAM) should append this information to the broadband remote access server (BRAS), and the BRAS transparently delivers it. If the Circuit-ID or Remote-ID tag is not present in DHCP option 82, a string of 0/0/0/0/0/0 should be appended to the NAS-Port-ID tag.

The following examples illustrate this format:

• NAS-Port-ID = atm 31/31/7:255.65535 name001/0/31/63/31/127

In this example, the subscriber interface type of the BRAS equipment is an ATM interface, the BRAS slot number is 31, the BRAS subslot number is 31, the BRAS port number is 7, the VPI is 255, and the VCI is 65535. The string name001/0/31/63/31/127 is the Circuit-ID or Remote-ID tag.

• NAS-Port-ID = eth 31/31/7:1234.2345 0/0/0/0/0/0

In this example, the subscriber interface type of the BRAS equipment is an Ethernet interface, the BRAS slot number is 31, the BRAS subslot number is 31, the BRAS port number is 7, the outer vlan-tag is 1234, and the inner vlan-tag is 2345. The string 0/0/0/0/0/0 is the default.

• NAS-Port-ID = eth 31/31/7:4096.2345 0/0/0/0/0/0

In this example, the subscriber interface type of the BRAS equipment is an Ethernet interface, the BRAS slot number is 31, the BRAS subslot number is 31, the BRAS port number is 7, and the VLAN ID is 2345. The string 0/0/0/0/0/0 is the default.

1.    enable

2.    configure terminal

3.    bba-group pppoe group-name

4.    virtual-template template-number

5.    nas-port-id format c

6.    end

The following is a sample configuration for the access concentrator side of a PPPoE over Ethernet configuration:

bba-group pppoe bba-pppoeoe
 virtual-template 1
 nas-port-id format c
!
interface Loopback0
 ip address 209.165.200.234 255.255.255.224
!
interface Virtual-Template1
 ip unnumbered Loopback0
no peer default ip address
 ppp authentication chap
!
interface FastEthernet0/0
 description PPPoEoE
 pppoe enable group bba-pppoeoe
!

The following is a sample configuration for the client side:

bba-group pppoe bbag-pppoeoe
 virtual-template 1
!
interface Virtual-Template1
 ip unnumbered Loopback0
 ppp chap hostname xyz
 ppp chap password 0 lab
!
interface Loopback0
 ip address 209.165.200.243 255.255.255.224
!
interface FastEthernet1/1
 no ip address
 pppoe enable group bbag-pppoeoe
!

The following is a sample configuration for the access concentrator side of a PPPoE over an ATM/AAL5 Subnetwork Access Protocol (SNAP) configuration:

bba-group pppoe bba-pppoeoa
 virtual-template 2
 nas-port-id format c
!
interface Loopback1
 ip address 209.165.200.245 255.255.255.224
!
interface Virtual-Template2
 ip unnumbered Loopback1
no peer default ip address
 ppp authentication chap
!
interface ATM2/0.1 multipoint
 description PPPoEoA
 pvc 1/100
  encapsulation aal5snap
  protocol pppoe group bba-pppoeoa
 !

The following is a sample configuration for the client side:

bba-group pppoe bbag-pppoeoa
 virtual-template 2
!
interface Virtual-Template2
 ip unnumbered Loopback1
 ppp chap hostname abc
 ppp chap password 0 lab
!
interface Loopback1
 ip address 209.165.200.247 255.255.255.224
!
interface ATM6/0.1 multipoint
 pvc 1/100
 encapsulation aal5snap
 protocol pppoe group bbag-pppoeoa
 !