Routers R1 and R2 have been configured to use Bidirectional Forwarding Detection? What is the advantage of doing this?
Routers R1 and R2 have been configured to use Bidirectional Forwarding Detection? What is the advantage of doing this?
Bidirectional Forwarding Detection (BFD) is a network protocol that is used to detect faults in the bidirectional path between two forwarding engines, which can be used to detect local link failures at both layers 1 (physical layer) and 2 (data link layer). BFD operates by sending control messages between two routers to detect any communication failures. If a failure is detected, BFD notifies the adjacent node almost immediately, usually within milliseconds, allowing for rapid rerouting of traffic to maintain network stability and connectivity. This swift detection and notification can prevent prolonged network outages and ensure that re-routing happens almost instantaneously.
D. BFD is able to discover local link failures at layers 1 and 2 and provides detection for this in less than one second. BFD can detect link failures at both the physical layer (Layer 1) and the data link layer (Layer 2) by sending and receiving packets at a very high rate (often every few milliseconds). If a BFD session detects a link failure, it can immediately signal this to the adjacent node, which can then take appropriate action to reroute traffic or take other measures to restore network connectivity.
BFD detects link failure when it does not get an echo. It does not need to signal to anyone after a failure is detect. E.g. when failure is detected, BFD will trigger the teardown of the OSPF adjancy over the failed link. This will then cause OSPF to very fast take an alternative route that is already locally in the OSPF LSDB.
D is corerct
A & B has no differences at all!
it´s a typo from the website, they meant 2 in one of them
yesy, option D: https://www.cisco.com/c/en/us/td/docs/ios/12_0s/feature/guide/fs_bfd.html