Fec Resolution; Ldp Session Capabilities - Alcatel-Lucent 7450 Manual

FEC Resolution

LDP will advertise and withdraw all interface IPv6 addresses using the Address/Address-
Withdraw message. Both the link-local unicast address and the configured global unicast
addresses of an interface are advertised.
All LDP FEC types can be exchanged over a LDP IPv6 LDP session like in LDP IPv4 session.
The LSR does not advertise a FEC for a link-local address and, if received, the LSR will not
resolve it.
A IPv4 or IPv6 prefix FEC can be resolved to an LDP IPv6 interface in the same way as it is
resolved to an LDP IPv4 interface. The outgoing interface and next-hop are looked up in RTM
cache. The next-hop can be the link-local unicast address of the other side of the link or a global
unicast address. The FEC is resolved to the LDP IPv6 interface of the downstream LDP IPv6 LSR
that advertised the IPv4 or IPv6 address of the next hop.
An mLDP P2MP FEC with an IPv4 root LSR address, and carrying one or more IPv4 or IPv6
multicast prefixes in the opaque element, can be resolved to an upstream LDP IPv6 LSR by
checking if the LSR advertised the next-hop for the IPv4 root LSR address. The upstream LDP
IPv6 LSR will then resolve the IPv4 P2MP FEC to one of the LDP IPV6 links to this LSR.
Note that in Release 13.0, a P2MP FEC with an IPv6 root LSR address and carrying one or more
IPv4 or IPv6 multicast prefixes in the opaque element, is not supported. Thus, manually
configured mLDP P2MP LSP, NG-mVPN, and dynamic mLDP will not be able to operate in an
IPv6-only network.
A PW FEC can be resolved to a targeted LDP IPv6 adjacency with an LDP IPv6 LSR if there is a
context for the FEC with local spoke-SDP configuration or spoke-SDP auto-creation from a
service such as BGP-AD VPLS, BGP-VPWS or dynamic MS-PW.

LDP Session Capabilities

LDP supports advertisement of all FEC types over an LDP IPv4 or an LDP IPv6 session. These
FEC types are: IPv4 prefix FEC, IPv6 prefix FEC, IPv4 P2MP FEC, PW FEC 128, and PW FEC
129.
In addition, LDP supports signaling the enabling or disabling of the advertisement of the
following subset of FEC types both during the LDP IPv4 or IPv6 session initialization phase, and
subsequently when the session is already up.
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7450 ESS MPLS Guide
IPv4 prefix FEC—This is performed using the State Advertisement Control (SAC)
capability TLV as specified in draft-ietf-mpls-ldp-ip-pw-capability. The SAC capability
TLV includes the IPv4 SAC element having the D-bit (Disable-bit) set or reset to disable
Label Distribution Protocol
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