I can't seem to get an SR policy working between IGP domains using a PCE controller to guide the traffic.
My topology is as follows (full configs attached):
R1, R2 and PCE are in one ISIS domain. ISIS level-2 point-to-point is running and exchanging loopbacks.
R2, R3 and R4 are in another ISIS domain. ISIS level-2 point-to-point is running and exchanging loopbacks.
R1's loopback is redistributed into ISIS RIGHT.
R4's loopback is redistributed into ISIS LEFT.
R1 and R4 can reach each others loopbacks.
SR is configured everywhere. The SID index is the router number.
A PCEP session is running between R1 and PCE.
R2 is using `distribute link-state` - with a separate instance ID for both ISIS instances.
R2 has an iBGP session to PCE with the `link-state link-state` address-family.
I know that technically both ISIS instances don't need to be in different areas given that they are different IGP domains. This has been done to make it easier to visualise.
R2 has two policies configured. It is delegating path calculation to the PCE for both.
One policy has an endpoint of R2 (intra domain)
One policy has an endpoint of R4 (inter domain)
The intra domain policy to R2 works. The inter domain one to R4 does not.
RP/0/RP0/CPU0:PCE#show pce lsp detail
Sun May 12 13:59:45.491 UTC
PCE's tunnel database:
----------------------
PCC 10.1.1.1:
Tunnel Name: cfg_TO-R2_discr_100
Color: 100
Interface Name: srte_c_100_ep_10.1.1.2
LSPs:
LSP[0]:
source 10.1.1.1, destination 10.1.1.2, tunnel ID 2, LSP ID 5
State: Admin up, Operation active
Setup type: Segment Routing
Binding SID: 24006
Maximum SID Depth: 10
Preference: 100
Bandwidth: requested 0 kbps, applied 0 kbps
Protection type: protected-preferred
Prefix-SID algorithm: 0 (set: 0)
PCEP information:
PLSP-ID 0x2, flags: D:1 S:0 R:0 A:1 O:2 C:0
LSP Role: Single LSP
State-sync PCE: None
PCC: 10.1.1.1
LSP is subdelegated to: None
Reported path:
Metric type: IGP, Accumulated Metric 10
SID[0]: Node, Label 16002, Address 10.1.1.2
Computed path: (Local PCE)
Computed Time: Sun May 12 13:54:52 UTC 2024 (00:04:53 ago)
Metric type: IGP, Accumulated Metric 10
SID[0]: Node, Label 16002, Address 10.1.1.2
Reverse path: (Local PCE)
None
Computed Time: Sun May 12 13:54:52 UTC 2024 (00:04:53 ago)
Recorded path:
None
Disjoint Group Information:
None
SR Policy Association Group:
Color: 100, Endpoint: 10.1.1.2
Policy Name: srte_c_100_ep_10.1.1.2
Preference: 100
Tunnel Name: cfg_TO-R4_discr_100
Color: 100
Interface Name: srte_c_100_ep_10.1.1.4
LSPs:
LSP[0]:
source 10.1.1.1, destination 10.1.1.4, tunnel ID 1, LSP ID 0
State: Admin up, Operation down
Binding SID: None
Maximum SID Depth: 10
Preference: 100
Bandwidth: requested 0 kbps, applied 0 kbps
Protection type: protected-preferred
Prefix-SID algorithm: 0 (set: 0)
PCEP information:
PLSP-ID 0x1, flags: D:1 S:0 R:0 A:1 O:0 C:0
LSP Role: Single LSP
State-sync PCE: None
PCC: 10.1.1.1
LSP is subdelegated to: None
Reported path:
None
Computed path: (Local PCE)
None
Computed Time: Sun May 12 13:54:52 UTC 2024 (00:04:53 ago)
Recorded path:
None
Disjoint Group Information:
None
SR Policy Association Group:
Color: 100, Endpoint: 10.1.1.4
Policy Name: srte_c_100_ep_10.1.1.4
Preference: 100
RP/0/RP0/CPU0:PCE#
You can see the tunnel with 10.1.1.4 end-point is down (from R1 to R4 - interdomain)
But 10.1.1.2 endpoint is fine (intradomain)
Does anyone have any idea what I might be missing? I know the PCE has see the full topology so for some reason it is not calculating it.
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