Example for Configuring Dynamic BFD for IPv6 Static Routes

Dynamic BFD for IPv6 static routes can fast detect link failures.

Networking Requirements

On the network shown in Figure 1, Device A is connected to Device B through Switch C. A static default route is configured on Device A so that Device A can communicate with external devices. A BFD session is configured between Device A and Device B to detect whether a link fault occurs.

Figure 1 Networking for configuring dynamic BFD for IPv6 static routes

Interfaces 1 and 2 in this example represent GE 0/1/0 and GE 0/1/8, respectively.

Precautions

When configuring dynamic BFD for IPv6 static routes, note the following points:

BFD has been enabled globally.
The parameters configured on the two ends of a BFD session must be consistent.

Configuration Roadmap

The configuration roadmap is as follows:

On Device A, configure an IPv6 static route to Device B.
Configure dynamic BFD for IPv6 static routes.

Data Preparation

To complete the configuration, you need the following data:

Peer IPv6 address to be detected by BFD
Default values of the local detection multiplier and of the minimum intervals at which BFD Control packets are sent and received

Procedure

Configure an IPv6 address for each interface. For configuration details, see Configuration Files in this section.

Configure IPv6 static routes.

# On Device A, configure a static route to 2001:db8:8::1/64.

[~DeviceA] ipv6 route-static 2001:db8:8:: 64 2001:db8:200::2
[*DeviceA] commit

# On Device A, check the IPv6 routing table. The following command output shows that static routes exist in the IPv6 routing table.

[~DeviceA] display ipv6 routing-table
Routing Table : _public_
         Destinations : 6        Routes : 6

Destination  : 2001:db8:7::                            PrefixLength : 64
NextHop      : 2001:db8:7::1                           Preference   : 0
Cost         : 0                                       Protocol     : Direct
RelayNextHop : ::                                      TunnelID     : 0x0
Interface    : GigabitEthernet0/1/8                    Flags        : D

Destination  : 2001:db8:7::1                           PrefixLength : 128
NextHop      : ::1                                     Preference   : 0
Cost         : 0                                       Protocol     : Direct
RelayNextHop : ::                                      TunnelID     : 0x0
Interface    : GigabitEthernet0/1/8                    Flags        : D

Destination  : 2001:db8:8::                           PrefixLength : 64
NextHop      : 2001:db8:200::2                         Preference   : 60
Cost         : 0                                       Protocol     : Static
RelayNextHop : 2001:db8:200::2                         TunnelID     : 0x0
Interface    : GigabitEthernet0/1/0                    Flags        : RD

Destination  : 2001:db8:200::                          PrefixLength : 64
NextHop      : 2001:db8:200::1                         Preference   : 0
Cost         : 0                                       Protocol     : Direct
RelayNextHop : ::                                      TunnelID     : 0x0
Interface    : GigabitEthernet0/1/0                    Flags        : D

Destination  : 2001:db8:200::1                         PrefixLength : 128
NextHop      : ::1                                     Preference   : 0
Cost         : 0                                       Protocol     : Direct
RelayNextHop : ::                                      TunnelID     : 0x0
Interface    : GigabitEthernet0/1/0                    Flags        : D

Destination  : FE80::                                  PrefixLength : 10
NextHop      : ::                                      Preference   : 0
Cost         : 0                                       Protocol     : Direct
RelayNextHop : ::                                      TunnelID     : 0x0
Interface    : NULL0                                   Flags        : D

# On Device B, configure the static route to 2001:db8:7::1/64.

[~DeviceB] ipv6 route-static 2001:db8:7:: 64 2001:db8:200::1
[*DeviceB] commit

Configure dynamic BFD for static routes.

# On Device A, bind a static route to a BFD session.

[~DeviceA] bfd
[*DeviceA-bfd] quit
[*DeviceA] ipv6 route-static bfd 2001:db8:200::2 local-address 2001:db8:200::1
[*DeviceA] ipv6 route-static 2001:db8:8:: 64 2001:db8:200::2 bfd enable
[*DeviceA] commit

# On Device B, bind a static route to a BFD session.

[~DeviceB] bfd
[*DeviceB-bfd] quit
[*DeviceB] ipv6 route-static bfd 2001:db8:200::1 local-address 2001:db8:200::2
[*DeviceB] ipv6 route-static 2001:db8:7:: 64 2001:db8:200::1 bfd enable
[*DeviceB] commit

Verify the configuration.

# After the configuration is complete, you can view that a BFD session has been established between Device A and Device B and is Up and that a static route is bound to it.

Use the command output on Device A as an example.

[~DeviceA] display bfd session all verbose
(w): State in WTR 
(*): State is invalid
------------------------------------------------------------------------------
  (Multi Hop) State : Up                   Name : dyn_16385
------------------------------------------------------------------------------
  Local Discriminator    : 16385            Remote Discriminator   : 16385
  Session Detect Mode    : Asynchronous Mode Without Echo Function
  BFD Bind Type          : Peer IP Address
  Bind Session Type      : Dynamic
  Bind Peer IP Address  : 2001:db8:200::2
  Bind Interface         : -
  Bind Source IP Address : 2001:db8:200::1
  FSM Board Id           : 3                TOS-EXP                : 7
  Min Tx Interval (ms) :50              Min Rx Interval (ms)  :50
  Actual Tx Interval (ms): 50               Actual Rx Interval (ms): 50
  Local Detect Multi   : 3               Detect Interval (ms)   : 150
  Echo Passive           : Disable          Acl Number             : -
  Destination Port       : 4784             TTL                    : 253
  Proc Interface Status  : Disable          Process PST            : Disable
  WTR Interval (ms)      : 0                Local Demand Mode      : Disable
  Active Multi           : 3
  Last Local Diagnostic  : No Diagnostic
  Bind Application       : STATICRTV6
  Session TX TmrID       : 0                Session Detect TmrID   : 0
  Session Init TmrID     : -                Session WTR TmrID      : -
  Session Echo Tx TmrID  : -
  Session Description    : -
------------------------------------------------------------------------------

     Total UP/DOWN Session Number : 1/0

Configuration Files

Device A configuration file

#
sysname DeviceA
#
bfd
#
interface GigabitEthernet0/1/0
 undo shutdown
 ipv6 enable
 ipv6 address 2001:db8:200::1/64
#
interface GigabitEthernet0/1/8
 undo shutdown
 ipv6 enable
 ipv6 address 2001:db8:7::1/64
#
ipv6 route-static bfd 2001:db8:200::2 local-address 2001:db8:200::1
ipv6 route-static 2001:db8:8:: 64 2001:db8:200::2 bfd enable
#
return

Device B configuration file

#
sysname DeviceB
#
bfd
#
interface GigabitEthernet0/1/0
 undo shutdown
 ipv6 enable
 ipv6 address 2001:db8:200::2/64
#
interface GigabitEthernet0/1/8
 undo shutdown
 ipv6 enable
 ipv6 address 2001:db8:8::1/64
#
ipv6 route-static bfd 2001:db8:200::1 local-address 2001:db8:200::2
ipv6 route-static 2001:db8:7:: 64 2001:db8:200::1 bfd enable
#
return