BFD on BDI Interfaces

The Cisco BFD on BDI Interfaces feature alleviates limitations on the maximum number of interfaces per system that switched virtual interfaces (SVI) impose. This document describes how to configure the Bidirectional Forwarding Detection (BFD) protocol on bridge domain interfaces (BDIs).

Information About BFD on Bridge Domain Interfaces

BFD on Bridge Domain Interfaces

Each BDI is associated with a bridge domain on which traffic is mapped using criteria defined and configured on the associated Ethernet flow points (EFPs). You can associate either single or multiple EFPs with a given bridge domain. Thus you can establish a BFD single-hop session over BDI interfaces that are defined in either a global table or a VPN routing and forwarding (VRF) table, and all existing single-hop BFD clients will be supported for BFD over BDI.

The Cisco BFD on BDI feature does not affect BFD stateful switchover (SSO) on platforms that are SSO capable.

How to Configure BFD on BDI Interfaces

Enabling BFD on a Bridge Domain Interface

Perform these steps to enable single hop BFD on an individual BDI interface.


Note

Multihop BFD is not interface specific so you do not need BDI interface-level configuration to establish multihop BFD sessions.

Before you begin

Two or more nodes must be connected.

Procedure

Step 1

enable

Example:


Router> enable

Enables privileged EXEC mode.

  • Enter your password if prompted.

Step 2

configure terminal

Example:


Router# configure terminal

Enters global configuration mode.

Step 3

bfd-template single-hop template-name

Example:


Router(config)# bfd-template single-hop bfdtemplate1

Creates a single-hop BFD template and enters BFD configuration mode.

Step 4

interval min-tx milliseconds min-rx milliseconds multiplier multiplier-value

Example:


Router(bfd-config)# interval min-tx 120 min-rx 100 multiplier 3

Configures the transmit and receive intervals between BFD packets, and specifies the number of consecutive BFD control packets that must be missed before BFD declares that a peer is unavailable.

Step 5

interface type number

Example:


Router(config)# interface bdi 100

Configures a bridge domain interface and enters interface configuration mode.

Step 6

ip address ip-address mask

Example:


Router(config-if)# ip address 10.201.201.1 255.255.255.0

Configures an IP address for the interface.

Step 7

bfd template template name

Enables the BFD template.

Step 8

exit

Example:


Router(config-if)# exit

Exits interface configuration mode and returns to global configuration mode.

Associating an Ethernet Flow Point with a Bridge Domain

Before you begin

BFD must be enabled on both nodes.

Procedure

Step 1

enable

Example:


Router> enable

Enables privileged EXEC mode.

  • Enter your password if prompted.

Step 2

configure terminal

Example:


Router# configure terminal

Enters global configuration mode.

Step 3

interface type slot/subslot/port

Example:


Router(config)# interface GigabitEthernet0/0/3

Configures an interface type and enters interface configuration mode.

Step 4

no ip address

Example:


Router(config-if)# no ip address

Disables IP processing.

Step 5

negotiation auto

Example:

Router(config-if)# negotiation auto

Enables the autonegotiation protocol to configure the speed, duplex, and automatic flow control of the interface.

Step 6

cdp enable

Example:

Router(config-if)# cdp enable

Enables Cisco Discovery Protocol on the interface.

Step 7

service instance id service-type

Example:

Router(config-if)# service instance 2 ethernet

Configures an Ethernet service instance and enters service instance configuration mode.

Step 8

encapsulation dot1q vlan-id

Example:

Router(config-if-srv)# encapsulation dot1q 2

Enables IEEE 802.1Q encapsulation of traffic on the subinterface.

Step 9

rewrite ingress tag pop 1 symmetric

Example:

Router(config-if-srv)# rewrite ingress tag pop 1 symmetric

Specifies removal of the outermost tag from the frame ingressing the service instance and the addition of a tag in the egress direction.

Step 10

exit

Example:


Router(config-if)# exit

Exits service instance configuration mode and returns to interface configuration mode.

Step 11

exit

Example:


Router(config-if)# exit

Exits interface configuration mode and returns to global configuration mode.

Step 12

bridge-domain vlan-id

Example:

Router(config)# bridge-domain 2

Associates the bridge domain with the Ethernet flow point.

Example:

What to do next

Configuration Examples for BFD on BDI Interfaces

Examples for BFD on BDI Interfaces

The following example shows how to configure BFD on a BDI. 


Router#show bfd neighbors

IPv4 Sessions
NeighAddr                              LD/RD         RH/RS     State     Int
10.1.1.2                             2049/1          Up        Up        BD2
Router#
Router#show running interface gi0/0/3
Building configuration...

Current configuration : 230 bytes
!
interface GigabitEthernet0/0/3
no ip address
ip pim passive
ip igmp version 3
negotiation auto
cdp enable
service instance 2 ethernet
  encapsulation dot1q 2
  rewrite ingress tag pop 1 symmetric
  bridge-domain 2
!
end

Router#show running interface bdi2

Building configuration...

Current configuration : 127 bytes
!
interface BDI2
ip address 10.1.1.3 255.255.255.0
bfd interval 100 min_rx 100 multiplier 3
bfd neighbor ipv4 10.1.1.2
end

And similarly for the other node: 


Router2#show running interface bdi2

Building configuration...

Current configuration : 127 bytes
!
interface BDI2
ip address 10.1.1.2 255.255.255.0
bfd interval 100 min_rx 100 multiplier 3
bfd neighbor ipv4 10.1.1.3
end

ED3#show run int gig0/0/3
Building configuration...

Current configuration : 195 bytes
!
interface GigabitEthernet0/0/3
no ip address
negotiation auto
cdp enable
service instance 2 ethernet
  encapsulation dot1q 2
  rewrite ingress tag pop 1 symmetric
  bridge-domain 2
!
end

Router2#show bfd neighbors

IPv4 Sessions
NeighAddr                              LD/RD         RH/RS     State     Int
10.1.1.3                                1/2049       Up        Up        BD2
ED3#