Configuring Optimized BFD Path
To address BFD flaps, Netvisor ONE offers an optimized path for BFD control packets to reach a destination vRouter. BFD packets are relayed by the Netvisor ONE OS from the switch to the destination vRouter using a PCIe link which connects one of the switch ports to the host CPU. The BFD fastpath functionality alleviates BFD timeout/delay issues when other high bandwidth traffic is coming to the host CPU.
The optimized path option can be enabled or disabled using the command:
CLI (network-admin@leaf1) > system-settings-modify
system-settings-modify  | 
Use this command to modify system settings.  | 
Specify one or more of the following options:  | 
|
optimize-arps|no-optimize-arps  | 
Enable or disable ARP optimization.  | 
lldp|no-lldp  | 
Enable or disable LLDP.  | 
policy-based-routing|no-policy-based-routing  | 
Enable or disable Policy-Based Routing (PBR). This enables flexible packet forwarding and routing through user-defined policies.  | 
optimize-nd|no-optimize-nd  | 
Enable or disable ND optimization.  | 
reactivate-mac|no-reactivate-mac  | 
Enable or disable reactivation of aged out MAC entries.  | 
reactivate-vxlan-tunnel-mac|no-reactivate-vxlan-tunnel-mac  | 
Enable or disable reactivation of MAC entries over VXLAN tunnels.  | 
manage-unknown-unicast|no-manage-unknown-unicast  | 
Enable or disable unknown unicast management.  | 
manage-broadcast|no-manage-broadcast  | 
Enable or disable broadcast management  | 
block-loops|no-block-loops  | 
Enable or disable loop blocking.  | 
auto-trunk|no-auto-trunk  | 
Enable or disable auto trunking.  | 
auto-host-bundle|no-auto-host-bundle  | 
Enable or disable auto host bundling.  | 
cluster-active-active-routing|no-cluster-active-active-routing  | 
Enable or disable active-active routing on a cluster.  | 
fast-route-download|no-fast-route-download  | 
Enable or disable fast route download from routesnoop.  | 
fast-interface-lookup|no-fast-interface-lookup  | 
Enable or disable fast router interface lookup.  | 
routing-over-vlags|no-routing-over-vlags  | 
Enable or disable routing to vLAGs from cluster links.  | 
source-mac-miss to-cpu|copy-to-cpu  | 
Specify either of the options as the unknown source MAC learn behavior.  | 
use-igmp-snoop-l2|use-igmp-snoop-l3  | 
Specify whether L2 or L3 tables are to be used for IGMP snooping.  | 
vle-tracking-timeout <3..30>  | 
Set a VLE tracking timeout as a value between 3 and 30s. The default timeout is 3s.  | 
pfc-buffer-limit pfc-buffer-limit-string  | 
Specify the percent of global system buffer space allowed for PFC.  | 
cosq-weight-auto|no-cosq-weight-auto  | 
Specify either of the options to enable or disable automatic weight assignment for CoS (Class of Service) queues based on min-guarantee configuration.  | 
lossless-mode|no-lossless-mode  | 
Enable or disable lossless mode.  | 
stagger-queries|no-stagger-queries  | 
Stagger igmp/mld snooping queries.  | 
host-refresh|no-host-refresh  | 
Enable or disable refreshing host ARP entries to keep L2 entries active.  | 
proxy-conn-retry|no-proxy-conn-retry  | 
Enable or disable proxy connection retry.  | 
proxy-conn-max-retry 0..10  | 
Set the maximum number of proxy connection retry attempts as a value between 0 and 10.  | 
proxy-conn-retry-interval 100..2000  | 
Set the number of milliseconds to wait between proxy connection retry attempts. This is a value between 100 and 2000.  | 
nvos-debug-logging|no-nvos-debug-logging  | 
Logging mode selection (Direct OR viz. nvlog demon)  | 
manage-l2-uuc-drop|no-manage-l2-uuc-drop  | 
Enable or disable L2 UUC (Unknown Unicast Drop) towards data port.  | 
xcvr-link-debug|no-xcvr-link-debug  | 
Enable or disable system debug to capture link information.  | 
fastpath-bfd|no-fastpath-bfd  | 
Enable or disable BFD fastpath.  | 
For example, the command below enables BFD fastpath:
CLI (network-admin@leaf1) > system-settings-modify fastpath-bfd
This command creates a new vFlow which redirects all BFD packets to CPU through the PCIe link.
To see the status of BFD fastpath on a switch, use the command system-settings-show. For example, the BFD fastpath status can be viewed exclusively using the command:
CLI (network-admin@leaf1) > system-settings-show format fastpath-bfd
fastpath-bfd: off
Netvisor ONE has the transmission queue tx-class-inband-bfd for sending out BFD packets. For reception, the rx-bfd queue is used.
To view the details of the transmission queue, use the command:
CLI (network-admin@leaf1) > nv-queue-stats-show name tx-class-inband-bfd
To view the receiver queue details, use the command:
CLI (network-admin@leaf1) > nv-queue-stats-show name rx-bfd