Static Segment Configuration; Dynamic Sid Allocation; Label Forwarding Entry Installation Based On Sids - H3C SR6600 Command Reference Manual

2. Label forwarding entry installation based on
the allocated labels to create label forwarding entries.
3. SRLSP
dynamically create SRLSPs.
When the ingress node of an SRLSP receives a packet, it adds labels to the packet and forwards the
packet to the egress node through the SRLSP. After receiving a packet from the SRLSP, the egress
node removes the label and forwards the packet based on the routing table.
You can bind a higher layer application (for example, MPLS TE) to an SRLSP to forward traffic of the
application through the SRLSP.

Static segment configuration

Static MPLS SR provides the following methods for configuring static segments for a destination:
•
Prefix segment method—Manually configure the incoming label, outgoing label, and next hop
for the destination address prefix on each SR node.
•
Adjacency segment method—Manually configure the incoming label and next hop for the
adjacency to the neighbor on each SR node.

Dynamic SID allocation

MPLS SR expands IGP protocols such as IS-IS and OSPF to advertise SIDs in IGP protocol packets.
MPLS SR provides the following methods for dynamically allocating and advertising SIDs:
•
Prefix SID—After you configure an SID for the loopback address on each SR node, the SIDs
uniquely identify the SR nodes. All SR nodes in the SR domain use an IGP to advertise their
own prefix SIDs. After receiving advertised prefix SIDs, each SR node calculates the prefix
SIDs to the advertisers.
The prefix SID advertisement can be one of the following types:
Absolute value advertisement—Each SR node advertises the prefix SID absolute value

and the SRGB.
Index value advertisement—Each SR node advertises the prefix SID index and the

SRGB.
Each SR node is assigned a globally unique index value for the node's prefix. The prefix SID
an SR node allocates for a prefix equals the SRBG base of the SR node plus the index for
that prefix.
NOTE:
The device supports only the index value advertisement in the current software release.
•
Adjacency SID—Each SR node with adjacency SID allocation enabled allocates SIDs for the
IGP adjacencies (that is, the links to its IGP neighbors), and uses the SIDs to identify the links.

Label forwarding entry installation based on SIDs

Label forwarding entry installation based on prefix SIDs
Label forwarding entries based on prefix SIDs can be static or dynamic.
•
Static label forwarding entries—The device creates local label forwarding entries based on
manually configured incoming labels, outgoing labels, and next hops.
•
Dynamic label forwarding entries—The device uses the IGP to flood in the SR domain the
local SRGB and the index of the prefix SID for the local loopback interface. Based on the
setup. You can manually configure SRLSPs, or use an IGP or a controller to
SIDs. All MPLS SR devices in the SR domain use
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