For any of the LFA methods to work properly, there must be a router in the backup path that will forward traffic addressed to the destination without sending it back to the source. Which of the following statements describes the way R-LFA selects such a router?
R-LFA (Remote Loop-Free Alternate) is a method that can select either an immediate neighbor or a remote router to be used as a backup next hop, as long as the backup path coincides with the path that will become active after IGP reconvergence.
Which of the following statements about segment routing fast re-route is FALSE?
On a Nokia 7750 SR, R-LFA and TI-LFA cannot be enabled independently; they must be enabled together. The parameter 'max-sr-frr-labels' limits the number of labels that R-LFA can add to the data packet encapsulation.
Which of the following is not required to be advertised by a router participating in Segment Routing?
SRGB when SRv6 is configured: This is not required to be advertised, SRGB(Segment Routing Global Block) is only used for SR-MPLS and is not needed when SRv6 is configured. Instead, SRv6 uses the IANA-assigned IPv6 address space.
Which of the following list of SR-TE attributes has to be advertised among routers?
In SR-TE, routers need to advertise certain attributes of their links to other routers in the network in order to calculate traffic-engineered paths. These attributes include:
Administrative groups that each link belongs to: This information is used to restrict the use of certain links to specific traffic types or groups.
TE metric of links: This information is used to calculate the cost of using a particular link for a traffic-engineered path.
Bandwidth availability of each link: This information is used to control the amount of traffic that can be sent over a particular link.
SRLG that each link belongs to: This information is used to avoid routing over the same physical link. Link status up/down is not needed to be advertised as it is part of the IGP protocol and is used to check the reachability of a link.
Which of the following statements about primary and secondary SR-TE LSP paths is FALSE?
Typically, in SR-TE, only two paths can be configured for a given SR-TE LSP: primary path and secondary path. The primary path is used for normal traffic forwarding, and the secondary path is used as a backup in case the primary path fails. Only one LSP path forwards the traffic at any time.
