Which two discovery mechanism does LDP support?

3 thoughts on “Which two discovery mechanism does LDP support?”

1. B and E is correct, “targeted” is a session not “Discovery”

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2. B&E are correct. A “targeted session” is done through the “extended discovery” mechanism. This is asking for the name of the discovery mechanism.

   “If an LSR is one hop from its neighbor, it is directly connected to its neighbor. The LSR sends out LDP
   link hello messages as User Datagram Protocol (UDP) packets to all the routers on the subnet
   (multicast). A neighboring LSR may respond to the link hello message, allowing the two routers to
   establish an LDP session. This process is called basic discovery.

   If the LSR is more than one hop from its neighbor, it is nondirectly connected to its neighbor. For these
   nondirectly connected neighbors, the LSR sends out a targeted hello message as a UDP packet that is
   specifically addressed to that LSR (unicast). The nondirectly connected LSR responds to the hello
   message, and the two routers begin to establish an LDP session. This process is called extended
   discovery.

   An MPLS LDP targeted session is a label distribution session between routers that are not directly
   connected. You establish nondirectly connected MPLS LDP sessions by enabling the transmission of
   targeted hello messages.”

   https://www.cisco.com/c/en/us/td/docs/switches/datacenter/sw/5_x/nx-os/mpls/configuration/guide/mpls_cg/mp_ldp_overview.pdf

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3. The correct answer D and E, there is no extended

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