Contents

Introduction

Components Used

Restrictions for Bridge Domain Interfaces

Summary Steps

Detailed Steps

Network Diagram

Configurations

Assigning a MAC Address

Verifying Bridge Domain Interface Configuration

DETAILED STEPS

Technical Assistance

Introduction

A bridge domain must include a set of logical interfaces that participate in Layer 2 learning and forwarding. You can optionally configure a VLAN identifier and a routing interface for the bridge domain to also support Layer 3 IP routing.

The Cisco ISR 4000 Series Integrated Services Routers support the bridge domain interface (BDI) feature for packaging Layer 2 Ethernet segments into Layer 3 IP.

Bridge domain interface supports the following features:

- IP termination

- Layer 3 VPN termination

- Address Resolution Protocol (ARP), G-ARP, and P-ARP handling

- MAC address assignment

Prior to configuring a bridge domain interface, you must understand the following concepts:

- Ethernet Virtual Circuit Overview

- Bridge Domain Interface Encapsulation

- Assigning a MAC Address

- Support for IP Protocols

- Support for IP Forwarding

- Packet Forwarding

- Bridge Domain Interface Statistics

Components Used

The information in this document is based on ISR 4000 router

Restrictions for Bridge Domain Interfaces

The following are the restrictions pertaining to bridge domain interfaces:

Only 4096 bridge domain interfaces are supported per system.

For a bridge domain interface, the maximum transmission unit (MTU) size can be configured between 1500 and 9216 bytes.

Bridge domain interfaces support only the following features:

- IPv4 Multicast

- QOS marking and policing. Shaping and queuing are not supported

- IPv4 VRF

- IPv6 unicast forwarding

- Dynamic routing such as BGP, OSPF, EIGRP, RIP, ISIS, and STATIC

- Hot Standby Router Protocol (HSRP) from IOS XE 3.8.0 onwards.

- Virtual Router Redundancy Protocol (VRRP) from IOS XE 3.8.0 onwards.

- Bridge domain interfaces do not support the following features:

- PPP over Ethernet (PPPoE)

- Bidirectional Forwarding Detection (BFD) protocol

- Netflow

- QoS

- Network-Based Application Recognition (NBAR) or Advanced Video Coding (AVC)

- MPLS TE built over BDI interface is not supported and Blackholed.

Summary Steps

1. enable

2. configure terminal

3. interface BDI interface number

4. encapsulation encapsulation dot1q <first-tag> [second-dot1q <second-tag>]

5. Do one of the following:

– ip address ip-address mask

– ipv6 address { X:X:X:X::X link-local | X:X:X:X::X / prefix [ anycast | eui-64 ] | autoconfig [ default ]}

6. mac-address { mac-address }

7. no shut

8. interface GigabitEthernet interface number

9. no ip address

10. service instance [number] ethernet

11. encapsulation dot1q <first-tag>

12. bridge-domain <number>

Detailed Steps

Command or Action

Purpose

Step 1

configure terminal

Router# configure terminal

Enters global configuration mode.

Step 2

interface BDI {interface number}

Router(config-if)# interface BDI3

Specifies a bridge domain interface on a Cisco ISR 4000 Series Integrated Services Router.

Step 3

encapsulation encapsulation dot1q <first-tag> [second-dot1q <second-tag>]

Router(config-if)# encapsulation dot1Q 1 second-dot1q 2

Defines the encapsulation type.

The example shows how to define dot1q as the encapsulation type.

Step 4

Do one of the following:

ip address ip-address mask

ipv6 address {X:X:X:X::X link-local | X:X:X:X::X/prefix [ anycast | eui-64 ] | autoconfig [ default ]}

Router(config-if)# ip address 100.1.1.1 255.255.255.0

Router(config-if)# ipv6 address AB01:CD1:123:C::/64 eui-64

Specifies either the IPv4 or IPv6 address for the bridge domain interface.

Step 6

match security-group destination tag sgt-number

Router(config-route-map)# match security-group destination tag 150

Configures the value for security-group destination security tag.

Step 6

mac address {mac-address}

Router(config-if)# mac-address 1.1.1

Specifies the MAC address for the bridge domain interface.

Step 7

no shut

Router(config-if)# no shut

Enables the bridge domain interface.

Step 8

shut

Router(config-if)# shut

Disables the bridge domain interface on the Cisco ISR 4000 Series Integrated Services Router.

Network Diagram

Configurations

ISR 4000-1

ISR 4000-2

interface BDI1

mac-address 0001.0001.0001

ip address 100.1.1.1 255.255.255.0

encapsulation dot1Q 100

end

!

interface GigabitEthernet0/0/1

no ip address

negotiation auto

service instance 100 ethernet

encapsulation dot1q 100

bridge-domain 1

no shut

!

interface BDI1

mac-address 0002.0002.0002

ip address 100.1.1.2 255.255.255.0

encapsulation dot1Q 100

end

!

interface GigabitEthernet0/0/0

no ip address

negotiation auto

service instance 100 ethernet

encapsulation dot1q 100

bridge-domain 1

no shut

!

Assigning a MAC Address

All the bridge domain interfaces on the Cisco ISR 4000 chassis share a common MAC address. The first bridge domain interface on a bridge domain is allocated a MAC address. Thereafter, the same MAC address is assigned to all the bridge domain interfaces that are created in that bridge domain.

Verifying Bridge Domain Interface Configuration

DETAILED STEPS

Step 1 show interfaces bdi

Displays the configuration summary of the corresponding BDI.

Router# showlik interfaces bdi 1

BDI1 is up, line protocol is up

Hardware is BDI, address is 0001.0001.0001 (bia 00c8.8bee.5993)

Internet address is 100.1.1.1/24

MTU 1500 bytes, BW 1000000 Kbit/sec, DLY 10 usec,

reliability 255/255, txload 1/255, rxload 1/255

Encapsulation 802.1Q VLAN, Vlan ID 100, loopback not set

Keepalive not supported

ARP type: ARPA, ARP Timeout 04:00:00

Last input 00:06:07, output 00:00:50, output hang never

Last clearing of "show interface" counters never

Input queue: 0/375/0/0 (size/max/drops/flushes); Total output drops: 0

Queueing strategy: fifo

Output queue: 0/40 (size/max)

5 minute input rate 0 bits/sec, 0 packets/sec

5 minute output rate 0 bits/sec, 0 packets/sec

30 packets input, 3366 bytes, 0 no buffer

Received 0 broadcasts (0 IP multicasts)

0 runts, 0 giants, 0 throttles

0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored

87 packets output, 22568 bytes, 0 underruns

0 output errors, 0 interface resets

0 unknown protocol drops

0 output buffer failures, 0 output buffers swapped out

Step 2 show platform software interface fp active name

Displays the bridge domain interface configuration in a Forwarding Processor.

Router# show platform software interface fp active name bdi 1

Name: BDI1, ID: 8, QFP ID: 9, Schedules: 4096

Type: BDI, State: enabled, SNMP ID: 4, MTU: 1500

IP Address: 100.1.1.1

IPV6 Address: ::

Flags: ipv4

ICMP Flags: unreachables, no-redirects, no-info-reply, no-mask-reply

ICMP6 Flags: unreachables, no-redirects

SMI enabled on protocol(s): UNKNOWN

Authenticated-user:

FRR linkdown ID: 65535

Bridge-domain ID: 1

BDI FLAG: 0

vNet Name: , vNet Tag: 0, vNet Extra Information: 0

Dirty: unknown

AOM dependency sanity check: PASS       //signifies that the BDI hardware programming is correct.

AOM Obj ID: 109

Step 3 show platform hardware qfp active interface if-name

Displays the bridge domain interface configuration in a data path.

Router# show platform hardware qfp active interface if-name BDI1

General interface information

Interface Name: BDI1

Interface state: VALID

Platform interface handle: 8

QFP interface handle: 9

Rx uidb: 32761

Tx uidb: 32759

Channel: 0

Interface Relationships

BGPPA/QPPB interface configuration information

Ingress: BGPPA/QPPB not configured. flags: 0000

Egress : BGPPA not configured. flags: 0000

ipv4_input enabled.

ipv4_output enabled.

layer2_input enabled.

layer2_output enabled.

ess_ac_input enabled.

Features Bound to Interface:

2 GIC FIA state

65 PUNT INJECT DB

69 cpp_l2bd_svr

41 icmp_svr

43 ipfrag_svr

44 ipreass_svr

Protocol 0 - ipv4_input

FIA handle - CP:0x56432e2146c0 DP:0xead8fc80

IPV4_INPUT_DST_LOOKUP_ISSUE (M)

IPV4_INPUT_ARL_SANITY (M)

IPV4_INPUT_DST_LOOKUP_CONSUME (M)

IPV4_INPUT_FOR_US_MARTIAN (M)

IPV4_INPUT_LOOKUP_PROCESS (M)

IPV4_INPUT_IPOPTIONS_PROCESS (M)

IPV4_INPUT_GOTO_OUTPUT_FEATURE (M)

Protocol 1 - ipv4_output

FIA handle - CP:0x56432e213fb8 DP:0xead9d100

IPV4_VFR_REFRAG (M)

IPV4_OUTPUT_L2_REWRITE (M)

IPV4_OUTPUT_FRAG (M)

BDI_VLAN_TAG_ATTACH

BDI_LAYER2_LOOKUP_GOTO

LAYER2_BRIDGE

BDI_OUTPUT_GOTO_OUTPUT_FEATURE

IPV4_OUTPUT_DROP_POLICY (M)

DEF_IF_DROP_FIA (M)

Protocol 8 - layer2_input

FIA handle - CP:0x56432e214d80 DP:0xead83080

LAYER2_INPUT_SIA (M)

LAYER2_INPUT_LOOKUP_PROCESS (M)

LAYER2_INPUT_GOTO_OUTPUT_FEATURE (M)

Protocol 9 - layer2_output

FIA handle - CP:0x56432e214000 DP:0xead9c880

BDI_VLAN_TAG_ATTACH

BDI_LAYER2_LOOKUP_GOTO

LAYER2_BRIDGE

BDI_OUTPUT_GOTO_OUTPUT_FEATURE

LAYER2_OUTPUT_DROP_POLICY (M)

DEF_IF_DROP_FIA (M)

Protocol 14 - ess_ac_input

FIA handle - CP:0x56432e2140d8 DP:0xead9af00

PPPOE_GET_SESSION

ESS_ENTER_SWITCHING

PPPOE_HANDLE_UNCLASSIFIED_SESSION

DEF_IF_DROP_FIA (M)

Step 4 debug platform hardware qfp feature

Router# debug platform hardware qfp active feature l2bd client all

The selected CPP L2BD Client debugging is on.

Step 5 platform trace runtime process forwarding-manager module

Enables the Forwarding Manager Route Processor and Embedded Service Processor trace messages for the Forwarding Manager process.

Router(config)# platform trace runtime slot F0 bay 0 process forwarding-manager module interfaces level info

Step 6 platform trace boottime process forwarding-manager module interfaces

Enables the Forwarding Manager Route Processor and Embedded Service Processor trace messages for the Route Processor Forwarding Manager process during bootup.

Router(config)# platform trace boottime slot R0 bay 1 process forwarding-manager forwarding-manager level max

Technical Assistance

Description

Link

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http://www.cisco.com/cisco