Hardware Assisted Bidirectional Forwarding Detection (BFD)

The hardware assisted Bidirectional Forwarding Detection (BFD) feature expands on the existing ExtremeXOS BFD capabilities.

Bidirectional Forwarding Detection (BFD) hardware assist support provides the functionality to run a BFD session in hardware. Effective failure detection requires BFD to run at high frequencies (using aggressive timers as low as 3 ms), which is not possible in the software mode because of CPU and ExtremeXOS restrictions.

To make BFD sessions run in the hardware, the following configuration is required.
  • Unused front panel port (not available for switching the user data traffic) configured as a loopback port. The port is used internally by the BFD hardware to send control packets.
  • IPforwarding is enabled on the BFD interfaces.
  • Nexthop MAC address of neighbor should be known for the session creation. BFD process triggers ARP to resolve the next hop MAC address, if not configured statically.

Supported Platforms

  • Summit X460-G2 series switches, standalone only

New CLI Commands

configure bfd hardware-assist [primary | secondary] loopback-port [port |none]

Changed CLI Commands

The following show commands are changed to show the hardware assist information (shown in bold):

#show bfd  
Number of  sessions                     : 0 
Sessions in Init State                  : 0 
Sessions in Down State                  : 0 
Sessions in Admin Down State            : 0 
Sessions in Up State                    : 0 

SNMP Traps for session-down             : Disabled  
SNMP Traps for session-up               : Disabled  
SNMP Traps for Batch Delay              : 1000 ms 
Hardware Assist Operational State       : Disabled(Loopback port not configured)
Hardware Assist Primary Loopback Port : 1
Hardware Assist Secondary Loopback Port : None
Maximum # of Hardware Assist Sessions   : 900
# show bfd session detail vr all 
    Neighbour      : 10.10.10.1          Local       : 10.10.10.2 
    Vr-Name        : bfd_vr10            Interface   : bfd_vlan10 
    Session Type   : Single Hop          State       : Up 
    … 
    Up Count                        : 1 
    Last Valid Packet Rx            : 00:51:49.300000 
    Last Packet Tx                  : 00:51:48.8200000  
    Hardware Assist                 : Yes 

    Neighbour      : 10.10.11.1          Local       : 10.10.11.2 
    Vr-Name        : bfd_vr10            Interface   : bfd_vlan11 
    Session Type   : Single Hop          State       : Up 
    … 
    Up Count                        : 1 
    Last Valid Packet Rx            : 00:51:49.300000 
    Last Packet Tx                  : 00:51:48.8200000  
    Hardware Assist                 : Yes