802.1ah Support for Ethernet Infrastructure

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With this feature, you can scale a Provider Bridged P802.1ad network using the existing Bridged and VLAN deployment. Although the current Cisco QinQ capability provides for VLAN scaling, this feature extends the scaling and interoperability between multiple vendors.

To make forwarding decisions, Bridges in a Provider Backbone Bridged Network (PBBN) need to know the MAC address of each host. MTP resolves the issue of MAC address learning by encapsulating the data packet and MAC addresses (source and destination) into a new Ethernet frame. The header of the new Ethernet frame contains:

• Backbone VLAN TAG (B-TAG) with 12 bit Backbone VLAN ID (B-VID)
• Destination Backbone MAC (B-MAC)
• Source Backbone MAC (B-MAC)
• Service Instance TAG (I-TAG) with 24 bit Service Instance ID (I-SID)

MAC scalability is implemented using the B-MACs. Since the new Ethernet frames are encapsulated with MAC address while traversing the PBBN, a bridge needs to learn only the B-MACs. The MAC addresses of hosts are hidden from the Provider Backbone Bridges (PBB), resulting in the PB Bridges to learn only the provider MAC address, independent of the number of hosts or the number of host MAC addresses supported. Since the data packets are sent to specific MAC addresses, the 802.1ah cloud is not flooded with unnecessary traffic. A MAC address may be a static entry in the MAC address table on the Backbone Core Bridge.

The VLAN scalability is implemented using the I-SID. The MTP achieves VLAN scalability by using a backbone VLAN TAG with 12 bit B-VID and the Service Instance TAG with 24 bit Service Instance ID to provide the VLAN scalability necessary to map large number of customers.

• MTP Software Architecture
• IB Backbone Edge Bridge
• Data Plane Processing
• MTP Configuration
• Scalability Information

SUMMARY STEPS

1.    enable

2.    configure terminal

3.    interface gigabitEthernet slot/port or interface tengigabitEthernet slot/port

4.    service instance id {Ethernet [service-name]}

5.    encapsulation untagged dot1q {any | vlan-id[vlan-id[vlan-id]} second-dot1q {any |vlan-id[vlan-id[vlan-id]]}

6.    rewrite ingress tag {push {dot1q vlan-id | dot1q vlan-id second-dot1q vlan-id | dot1ad vlan-id dot1q vlan-id} | pop {1 | 2} | translate {1-to-1 {dot1q vlan-id | dot1ad vlan-id}| 2-to-1 dot1q vlan-id | dot1ad vlan-id}| 1-to-2 {dot1q vlan-id second-dot1q vlan-id | dot1ad vlan-id dot1q vlan-id} | 2-to-2 {dot1q vlan-id second-dot1q vlan-id | dot1ad vlan-id dot1q vlan-id}} [symmetric]

7.    bridge-domain bridge-id c-mac

8.    exit

9.    exit

10.    ethernet mac-tunnel virtual mac-in-mac-tunnel-identifier

11.    bridge-domain bridge-id

12.    service instance id {Ethernet [service-name]}

13.    encapsulation dot1ah i-sid i-sid_number

14.    bridge-domain bridge-id c-mac

15.    exit

16.    exit

17.    exit

DETAILED STEPS

	Command or Action	Purpose
Step 1	enable Example: Device> enable	Enables privileged EXEC mode. Enter your password if prompted.
Step 2	configure terminal Example: Device# configure terminal	Enters global configuration mode.
Step 3	interface gigabitEthernet slot/port or interface tengigabitEthernet slot/port Example: Device(config)#interface GigabitEthernet 3/1	Specifies the Gigabit Ethernet interface to be configured, where: slot/port --Specifies the location of the interface
Step 4	service instance id {Ethernet [service-name]} Example: Device(config-if)#service instance 20 ethernet	Creates a service instance (an instance of an EVC) on an interface and sets the device into the config-if-srv mode.
Step 5	encapsulation untagged dot1q {any | vlan-id[vlan-id[vlan-id]} second-dot1q {any |vlan-id[vlan-id[vlan-id]]} Example: Device(config-if-srv)#encapsulation dot1q 40 second-dot1q 42	Configures the encapsulation. Defines the matching criteria to be used in order to map ingress dot1q frames on an interface to the appropriate service instance.
Step 6	rewrite ingress tag {push {dot1q vlan-id | dot1q vlan-id second-dot1q vlan-id | dot1ad vlan-id dot1q vlan-id} | pop {1 | 2} | translate {1-to-1 {dot1q vlan-id | dot1ad vlan-id}| 2-to-1 dot1q vlan-id | dot1ad vlan-id}| 1-to-2 {dot1q vlan-id second-dot1q vlan-id | dot1ad vlan-id dot1q vlan-id} | 2-to-2 {dot1q vlan-id second-dot1q vlan-id | dot1ad vlan-id dot1q vlan-id}} [symmetric] Example: [no] bridge-domain bridge-id c-mac Example: Device(config-if-srv)#rewrite ingress tag pop 1 symmetric	Specifies the tag manipulation that is to be performed on the frame ingress to the service instance.
Step 7	bridge-domain bridge-id c-mac Example: Device(config-if-srv)#bridge-domain 21 c-mac	Configuring the bridge domain. Binds the service instance to a bridge domain instance where bridge-id is the identifier for the bridge domain instance.
Step 8	exit Example: Device(config-if-srv)#exit	Exits the service instance mode.
Step 9	exit Example: Device(config-if)#exit	Exits interface mode.
Step 10	ethernet mac-tunnel virtual mac-in-mac-tunnel-identifier Example: Device(config)#ethernet mac-tunnel virtual 22	Configures mac-in-mac tunnel and creates a tunnel identifier for the 802.1ah cloud. Sets the configuration to config-tunnel-minm mode.
Step 11	bridge-domain bridge-id Example: Device(config-tunnel-minm)#bridge-domain 200	Binds the mac tunnel to the B-MAC bridge domain instance.
Step 12	service instance id {Ethernet [service-name]} Example: Device(config-tunnel-minm)#service in 23 ethernet	Defines the service instance to be used with B-VLAN. Set the configuration mode to config-tunnel-srv mode.
Step 13	encapsulation dot1ah i-sid i-sid_number Example: Device(config-tunnel-srv)#encapsulation dot1ah isid 24 Example:	Defines the matching criteria to be used to map 802.1ah frames with I-SID id to the appropriate EVC.
Step 14	bridge-domain bridge-id c-mac Example: Device(config-tunnel-srv)#bridge-domain 21 c-mac	Maps the I-SID used for forwarding the customer packets to a specific EVC on the interface. The bridge-id mentioned step 7 must match with bridge-id in this step to ensure proper configuration.
Step 15	exit Example: Device(config-tunnel-srv)#exit	Exits the mac-tunnel service instance mode.
Step 16	exit Example: Device(config-tunnel-minm)#exit	Exits the mac-tunnel mode.
Step 17	exit Example: Device(config)#exit	Exits the global config mode.

This example shows how to configure Excalibur MTP for Cisco 7600 Routers:

Device>enable
Device#configure terminal
Device(config)#interface GigabitEthernet 3/1
Device(config-if)#service instance 20 ethernet
Device(config-if-srv)#encapsulation dot1q 40 second-dot1q 42
Device(config-if-srv)#rewrite ingress tag pop 1 symmetric
Device(config-if-srv)#bridge-domain 21 c-mac
Device(config-if-srv)#exit
Device(config-if)#exit
Device(config)#ethernet mac-tunnel virtual 22
Device(config-tunnel-minm)#bridge-domain 200
Device(config-tunnel-minm)#service in 23 ethernet
Device(config-tunnel-srv)#encapsulation dot1ah isid 24
Device(config-tunnel-srv)#bridge-domain 21 c-mac
Device(config-tunnel-srv)#exit
Device(config-tunnel-minm)#exit
Device(config)#exit

Use the following commands to verify the MTP configuration:

• You can use the show platform mtp slot slot_num command to verify the MTP configuration. This command shows the information about MTP for each slot:

Device#sh platform mtp slot 3
SLOT        TUNNELENGINE         VLAN_LIST
 3          MacTunnelEngine3/0     200
 3          MacTunnelEngine3/1
 3          MacTunnelEngine3/2
 3          MacTunnelEngine3/3

• You can use show platform mtp c_bd c-vlan-id to view information about a specific C-VLAN:

Device#sh platform mtp c_bd 21
C_BD        B_BD           SLOT       PPE          C_BD_COUNT
 21         200             3          0               1
Router#

• You can use show platform mtp b_bd b-vlan-id to view information about a specific B-VLAN:

Device#sh platform mtp b_bd 200
B_BD        SLOT           PPE        B_BD_COUNT
200          3              0             1
Router#

• You can use show platform mtp befp b-efp-id to view information about a specific B-EFP:

Device#sh platform mtp befp 23
BEFP       C_BD           B_BD        SLOT           PPE          C_BD_COUNT
23         21             200          3              0              1
Router#

• You can use show ethernet service mac-tunnel summary to view a summary of information about a specific mac tunnel.
• You can use show ethernet service mac-tunnel id [detail] to view information about a specific mac tunnel, and the ID can range from 1 to 4094.

Device#show ethernet service mac-tunnel 1 detail
Tunnel Id: 1
EFP Microblocks:
****************
Microblock type: Bridge-domain
Bridge-domain: 20
No. of Service Instances: 1
Service Instance ID: 16000
Associated Tunnel Id: 1
Encapsulation: dot1ah 1 vlan-type 0x88E7
Rewrite: egress tag push dot1ah 1 vlan-type 0x88E7 symmetric
State: Up
mac-tunnel address map: 0001.0001.0001 0002.0002.0002
EFP Statistics:
   Pkts In   Bytes In   Pkts Out  Bytes Out
         0          0          0          0
EFP Microblocks:
****************
Microblock type: Bridge-domain
Bridge-domain: 1 c-mac
Microblock type: CFM
CFM encapsulation: