•
Device B calculates its incoming label and outgoing label and creates a label forwarding entry.
The incoming label is 16201. The outgoing label is 16201. The next hop is Device C.
•
Device A calculates its incoming label and outgoing label and creates a label forwarding entry.
The incoming label is 16201. The outgoing label is 16201. The next hop is Device B.
Label forwarding entry installation based on BGP EPE
Configure BGP EPE on border routers to assign SIDs to specific peers or peer groups.
Figure 4 Creating label forwarding entries by using BGP EPE
AS 100
In Label
5000
Nexthop
Device C IBGP
AS 200
Device C
EBGP
Device A
IBGP
Device B
EBGP
Device E
In Label
6000
Nexthop
Device D
IBGP
Device D
As shown in Figure 4 , you can configure BGP EPE on Device B to assign BGP peering SIDs to
EBGP neighbors Device C and Device D. BGP peering SIDs are locally significant and are not advertised to neighbors.
Label forwarding entry installation based on adjacency SIDs
When using adjacency SIDs, each device allocates a static or dynamic incoming label to the link to its neighbor. The label has local significance. Multiple devices can use the same adjacency SID.
Figure 5 Creating label forwarding entries based on adjacency SIDs
In Label
203
Nexthop
Device B
In Label
202
Nexthop
Device C
In Label
201
Nexthop
Device D
Device A Device B Device C Device D
As shown in Figure 5 , the devices are running the same IGP. After IGP adjacencies are established
between the devices, Device A, Device B, and Device C allocates labels and creates label forwarding entries as follows:
•
Device A allocates label 203 to the link to its neighbor Device B.
•
Device B allocates label 202 to the link to its neighbor Device C.
•
Device C allocates label 201 to the link to its neighbor Device D.
•
Device A creates a label forwarding entry with incoming label 203 and next hop Device B.
•
Device B creates a label forwarding entry with incoming label 202 and next hop Device C.
•
Device C creates a label forwarding entry with incoming label 201 and next hop Device D.
SRLSP setup
You can use the following methods to create SRLSPs:
•
Manually configure an SRLSP.
6
