This document gives several answers on frequently asked questions for PFRv3 channel state behavior. Q1: What are all the channel operational states from a BR (border role) perspective   and what are the rules/conditions to be in each state? A1: Channel state machine from border perspective: Overview In PfRv3, border channel has the following three stats: Provisional State: to indicate whether there's TC relying on this group on Channel <DSCP, Peer-Site-ID, Any-WAN-Exit>. RX State: detected by local data plane to indicate the Channel reachability from remote to local. TX State: detected by remote site, sending to local MC by unreachable TCA.   Rx state:  Tx state:   Q2: What are all the channel operational states from a master perspective and what are the rules/conditions to be in each state? A2: Channel state machine from a master perspective: In PfRv3, master channel has the following three stats: Not-available (Initial state); Not-available (no next-hop); Available; Available, but unreachable.   Q3: What are the channel states for Internet channels (site-id 255.255.255.255)? A3: Channel states differ from the states for regular channels: Channel Provisional State Machine: Channel Rx State Machine: Channel Tx State Machine:    Channel OIperational State Machine:   Q4: What happens with Internet channel if RIB loses 0.0.0.0/0 prefix over the Tunnel interface? A4: In this scenario, the channel nexthop will be 0.0.0.0 that means the channel next-hop is lost, but the channel state is still Reachable. At the same time the channel is not available because the channel nexthop is lost. ... View more