The following shows the detailed configuration for the creation of a mesh of SR-TE auto-LSPs. The network uses IS-IS with the backbone area being in Level 2 and the leaf areas being in Level 1.
The NSP is used for network discovery only and the NRC-P learns the network topology using BGP-LS.
Figure 1 shows the view of the multi-level IS-IS topology in the NSP GUI. The backbone L2 area is highlighted in green.
Figure 1. Multi-level IS-IS Topology in the NSP GUI
The mesh of SR-TE auto-LSPs is created in the backbone area and originates on an ABR node with address 192.168.48.199 (Phoenix 199). The LSP template uses a default path that includes an anycast SID prefix corresponding to a transit routers 192.168.48.184 (Dallas 184) and 192.168.48.185 (Houston 185).
The following is the configuration of transit router Dallas 184, which shows the creation of a loopback interface with the anycast prefix and the assignment of a SID to it. The same configuration must be performed on the transit router Houston 185. See lines marked with an asterisk (*).
*A:Dallas 184>config>router# info
---------------------------------------------------
echo "IP Configuration"
#--------------------------------------------------
if-attribute
admin-group "olive" value 20
admin-group "top" value 10
srlg-group "top" value 10
exit
interface "anycast-sid" *
address 192.168.48.99/32 *
loopback *
no shutdown *
exit
interface "system"
address 192.168.48.184/32
no shutdown
exit
interface "toJun164"
address 10.19.2.184/24
port 1/1/4:10
no shutdown
exit
interface "toSim185"
address 10.0.3.184/24
port 1/1/2
no shutdown
exit
interface "toSim198"
address 10.0.2.184/24
port 1/1/3
if-attribute
admin-group "olive"
exit
no shutdown
exit
interface "toSim199"
address 10.0.13.184/24
port 1/1/5
no shutdown
exit
interface "toSim221"
address 10.0.4.184/24
port 1/1/1
no shutdown
exit
interface "toSim223"
address 10.0.14.184/24
port 1/1/6
no shutdown
exit
#--------------------------------------------------
*A:Dallas 184>config>router>isis# info
----------------------------------------------
level-capability level-2
area-id 49.0000
database-export identifier 10 bgp-ls-identifier 10
traffic-engineering
advertise-router-capability area
level 2
wide-metrics-only
exit
interface "system"
ipv4-node-sid index 384
no shutdown
exit
interface "toSim198"
interface-type point-to-point
no shutdown
exit
interface "toSim185"
interface-type point-to-point
no shutdown
exit
interface "toSim221"
interface-type point-to-point
no shutdown
exit
interface "toSim199"
interface-type point-to-point
level 2
metric 100
exit
no shutdown
exit
interface "toSim223"
interface-type point-to-point
level 2
metric 100
exit
no shutdown
exit
interface "anycast-sid" *
ipv4-node-sid index 99 *
no shutdown *
exit
segment-routing
prefix-sid-range global
no shutdown
exit
no shutdown
----------------------------------------------
In the ingress LER Phoenix 199 router, the anycast SID is learned from both transit routers, but is currently resolved in IS-IS to transit router Houston 185. See lines marked with an asterisk (*).
*A:Phoenix 199# show router isis prefix-sids
===============================================================================
Rtr Base ISIS Instance 0 Prefix/SID Table
===============================================================================
Prefix SID Lvl/Typ SRMS AdvRtr
MT Flags
-------------------------------------------------------------------------------
192.168.48.194/32 399 1/Int. N Reno 194
0 NnP
192.168.48.194/32 399 2/Int. N Salt Lake 198
0 RNnP
192.168.48.194/32 399 2/Int. N Phoenix 199
0 RNnP
192.168.48.99/32 99 2/Int. N Dallas 184 *
0 NnP *
192.168.48.99/32 99 2/Int. N Houston 185 *
0 NnP *
192.168.48.184/32 384 2/Int. N Dallas 184
0 NnP
192.168.48.185/32 385 2/Int. N Houston 185
0 NnP
192.168.48.190/32 390 2/Int. N Chicago 221
0 RNnP
192.168.48.190/32 390 2/Int. N St Louis 223
0 RNnP
192.168.48.194/32 394 1/Int. N Reno 194
0 NnP
192.168.48.194/32 394 2/Int. N Salt Lake 198
0 RNnP
192.168.48.194/32 394 2/Int. N Phoenix 199
0 RNnP
192.168.48.198/32 398 1/Int. N Salt Lake 198
0 NnP
192.168.48.198/32 398 2/Int. N Salt Lake 198
0 NnP
192.168.48.198/32 398 2/Int. N Phoenix 199
0 RNnP
192.168.48.199/32 399 2/Int. N Salt Lake 198
0 RNnP
192.168.48.199/32 399 1/Int. N Phoenix 199
0 NnP
192.168.48.199/32 399 2/Int. N Phoenix 199
0 NnP
192.168.48.219/32 319 2/Int. N Salt Lake 198
0 RNnP
192.168.48.219/32 319 2/Int. N Phoenix 199
0 RNnP
192.168.48.219/32 319 1/Int. N Las Vegas 219
0 NnP
192.168.48.221/32 321 2/Int. N Chicago 221
0 NnP
192.168.48.221/32 321 2/Int. N St Louis 223
0 RNnP
192.168.48.223/32 323 2/Int. N Chicago 221
0 RNnP
192.168.48.223/32 323 2/Int. N St Louis 223
0 NnP
192.168.48.224/32 324 2/Int. N Chicago 221
0 RNnP
192.168.48.224/32 324 2/Int. N St Louis 223
0 RNnP
192.168.48.226/32 326 2/Int. N PCE Server 226
0 NnP
3ffe::a14:194/128 294 1/Int. N Reno 194
0 NnP
3ffe::a14:194/128 294 2/Int. N Phoenix 199
0 RNnP
3ffe::a14:199/128 299 1/Int. N Phoenix 199
0 NnP
3ffe::a14:199/128 299 2/Int. N Phoenix 199
0 NnP
-------------------------------------------------------------------------------
No. of Prefix/SIDs: 32 (15 unique)
-------------------------------------------------------------------------------
SRMS : Y/N = prefix SID advertised by SR Mapping Server (Y) or not (N)
S = SRMS prefix SID is selected to be programmed
Flags: R = Re-advertisement
N = Node-SID
nP = no penultimate hop POP
E = Explicit-Null
V = Prefix-SID carries a value
L = value/index has local significance
===============================================================================
*A:Phoenix 199# tools dump router segment-routing tunnel
====================================================================================
Legend: (B) - Backup Next-hop for Fast Re-Route
(D) - Duplicate
====================================================================================
-----------------------------------------------------------------------------------+
Prefix |
Sid-Type Fwd-Type In-Label Prot-Inst |
Next Hop(s) Out-Label(s) Interface/Tunnel-ID |
-----------------------------------------------------------------------------------+
192.168.48.99 *
Node Orig/Transit 200099 ISIS-0 *
10.0.5.185 200099 toSim185 *
3ffe::a14:194
Node Orig/Transit 200294 ISIS-0
fe80::62c2:ffff:fe00:0 200294 toSim194
3ffe::a14:199
Node Terminating 200299 ISIS-0
192.168.48.219
Node Orig/Transit 200319 ISIS-0
10.202.5.194 200319 toSim194
192.168.48.221
Node Orig/Transit 200321 ISIS-0
10.0.5.185 200321 toSim185
192.168.48.223
Node Orig/Transit 200323 ISIS-0
10.0.5.185 200323 toSim185
192.168.48.224
Node Orig/Transit 200324 ISIS-0
10.0.5.185 200324 toSim185
192.168.48.226
Node Orig/Transit 200326 ISIS-0
10.0.1.2 100326 toSim226PCEServer
192.168.48.184
Node Orig/Transit 200384 ISIS-0
10.0.5.185 200384 toSim185
192.168.48.185
Node Orig/Transit 200385 ISIS-0
10.0.5.185 200385 toSim185
192.168.48.190
Node Orig/Transit 200390 ISIS-0
10.0.5.185 200390 toSim185
192.168.48.194
Node Orig/Transit 200394 ISIS-0
10.202.5.194 200394 toSim194
192.168.48.198
Node Orig/Transit 200398 ISIS-0
10.0.9.198 100398 toSim198
192.168.48.199
Node Terminating 200399 ISIS-0
10.0.9.198
Adjacency Transit 262122 ISIS-0
10.0.9.198 3 toSim198
10.202.1.219
Adjacency Transit 262124 ISIS-0
10.202.1.219 3 toSim219
10.0.5.185
Adjacency Transit 262133 ISIS-0
10.0.5.185 3 toSim185
fe80::62c2:ffff:fe00:0
Adjacency Transit 262134 ISIS-0
fe80::62c2:ffff:fe00:0 3 toSim194
10.0.1.2
Adjacency Transit 262137 ISIS-0
10.0.1.2 3 toSim226PCEServer
10.0.13.184
Adjacency Transit 262138 ISIS-0
10.0.13.184 3 toSim184
10.0.2.2
Adjacency Transit 262139 ISIS-0
10.0.2.2 3 toSim226PCEserver202
10.202.5.194
Adjacency Transit 262141 ISIS-0
10.202.5.194 3 toSim194
------------------------------------------------------------------------------------
No. of Entries: 22
------------------------------------------------------------------------------------
Next, a policy must be configured to add the list of prefixes to which the ingress LER Phoenix 199 must auto-create SR-TE LSPs.
*A:Phoenix 199>config>router>policy-options# info
----------------------------------------------
prefix-list "sr-te-level2"
prefix 192.168.48.198/32 exact
prefix 192.168.48.221/32 exact
prefix 192.168.48.223/32 exact
exit
policy-statement "sr-te-auto-lsp"
entry 10
from
prefix-list "sr-te-level2"
exit
action accept
exit
exit
default-action drop
exit
exit
----------------------------------------------
Then, an LSP template of type mesh-p2p-srte must be configured, which uses a path with a loose-hop corresponding to anycast-SID prefix of the transit routers. The LSP template is then bound to the policy containing the prefix list. See lines marked with an asterisk (*).
*A:Phoenix 199>config>router>mpls# info
----------------------------------------------
cspf-on-loose-hop
interface "system"
no shutdown
exit
interface "toESS195"
no shutdown
exit
interface "toSim184"
no shutdown
exit
interface "toSim185"
admin-group "bottom"
srlg-group "bottom"
no shutdown
exit
interface "toSim194"
admin-group "bottom"
srlg-group "bottom"
no shutdown
exit
interface "toSim198"
no shutdown
exit
interface "toSim219"
no shutdown
exit
path "loose-anycast-sid" *
hop 1 192.168.48.99 loose *
no shutdown *
exit *
lsp-template "sr-te-level2-mesh" mesh-p2p-srte *
default-path "loose-anycast-sid" *
max-sr-labels 8 additional-frr-labels 2 *
pce-report enable *
no shutdown *
exit *
auto-lsp lsp-template "sr-te-level2-mesh" policy "sr-te-auto-lsp" *
no shutdown *
----------------------------------------------
One SR-TE LSP should be automatically created to each destination matching the prefix in the policy as soon as the router with the router ID matching the address of the prefix appears in the TE database.
The following shows the three SR-TE auto-LSPs created. See lines marked with an asterisk (*).
*A:Phoenix 199# show router mpls sr-te-lsp
===============================================================================
MPLS SR-TE LSPs (Originating)
===============================================================================
LSP Name To Tun Protect Adm Opr
Id Path
-------------------------------------------------------------------------------
Phoenix-SL-1 192.168.48.223 1 N/A Up Up
Phoenix-SL-2-Profile 192.168.48.223 2 N/A Up Up
Phoenix-SL-3-Profile 192.168.48.223 3 N/A Up Up
Phoenix-SL-4-Profile 192.168.48.223 4 N/A Up Up
Phoenix-SL-1-Profile 192.168.48.223 5 N/A Up Up
Phoenix-SL-2 192.168.48.223 6 N/A Up Up
Phoenix-SL-3 192.168.48.223 7 N/A Up Up
Phoenix-SL-4 192.168.48.223 8 N/A Up Up
sr-te-level2-mesh-192.168.48.198- 192.168.48.198 61442 N/A Up Up *
716803 *
sr-te-level2-mesh-192.168.48.221- 192.168.48.221 61443 N/A Up Up *
716804 *
sr-te-level2-mesh-192.168.48.223- 192.168.48.223 61444 N/A Up Up *
716805 *
-------------------------------------------------------------------------------
LSPs : 17
===============================================================================
The auto-generated name uses the syntax convention ‟TemplateName-DestIpv4Address-TunnelId”, as explained in Automatic Creation of an SR-TE Mesh LSP. The tunnel ID used in the name is the TTM tunnel ID, not the MPLS LSP tunnel ID. See lines marked with an asterisk (*).
*A:Phoenix 199# show router mpls sr-te-lsp "sr-te-level2-mesh-192.168.48.223-
716805" detail
===============================================================================
MPLS SR-TE LSPs (Originating) (Detail)
===============================================================================
-------------------------------------------------------------------------------
Type : Originating
-------------------------------------------------------------------------------
LSP Name : sr-te-level2-mesh-192.168.48.223-716805
LSP Type : MeshP2PSrTe LSP Tunnel ID : 61444 *
LSP Index : 126979 TTM Tunnel Id : 716805 *
From : 192.168.48.199 To : 192.168.48.2*
Adm State : Up Oper State : Up
LSP Up Time : 0d 00:02:12 LSP Down Time : 0d 00:00:00
Transitions : 3 Path Changes : 3
Retry Limit : 0 Retry Timer : 30 sec
CSPF : Enabled
Metric : N/A Use TE metric : Disabled
Include Grps : Exclude Grps :
None None
VprnAutoBind : Enabled
IGP Shortcut : Enabled BGP Shortcut : Enabled
IGP LFA : Disabled IGP Rel Metric : Disabled
BGPTransTun : Enabled
Oper Metric : 16777215
PCE Report : Enabled
PCE Compute : Disabled PCE Control : Disabled
Max SR Labels : 8 Additional FRR Labels: 2
Path Profile :
None
Primary(a) : loose-anycast-sid Up Time : 0d 00:02:12
Bandwidth : 0 Mbps
===============================================================================
These SR-TE auto-LSPs are also added into the tunnel table to be used by services and shortcut applications. See lines marked with an asterisk (*).
*A:Phoenix 199# show router tunnel-table
===============================================================================
IPv4 Tunnel Table (Router: Base)
===============================================================================
Destination Owner Encap TunnelId Pref Nexthop Metric
-------------------------------------------------------------------------------
10.0.5.185/32 isis (0) MPLS 524370 11 10.0.5.185 0
10.0.9.198/32 isis (0) MPLS 524368 11 10.0.9.198 0
10.0.13.184/32 isis (0) MPLS 524340 11 10.0.13.184 0
10.202.1.219/32 isis (0) MPLS 524333 11 10.202.1.219 0
10.202.5.194/32 isis (0) MPLS 524355 11 10.202.5.194 0
10.0.1.2/32 isis (0) MPLS 524364 11 11.0.1.2 0
10.0.2.2/32 isis (0) MPLS 524363 11 11.0.2.2 0
192.168.48.99/32 isis (0) MPLS 524294 11 10.0.5.185 10
192.168.48.184/32 ldp MPLS 65605 9 10.0.5.185 20
192.168.48.184/32 isis (0) MPLS 524341 11 10.0.5.185 20
192.168.48.185/32 ldp MPLS 65602 9 10.0.5.185 10
192.168.48.185/32 isis (0) MPLS 524371 11 10.0.5.185 10
192.168.48.190/32 ldp MPLS 65606 9 10.0.5.185 40
192.168.48.190/32 isis (0) MPLS 524362 11 10.0.5.185 40
192.168.48.194/32 ldp MPLS 65577 9 10.202.5.194 10
192.168.48.194/32 isis (0) MPLS 524331 11 10.202.5.194 10
192.168.48.198/32 sr-te MPLS 716803 8 192.168.48.99 16777215 *
192.168.48.198/32 ldp MPLS 65601 9 10.0.9.198 10
192.168.48.198/32 isis (0) MPLS 524369 11 10.0.9.198 10
192.168.48.219/32 ldp MPLS 65579 9 10.202.5.194 20
192.168.48.219/32 isis (0) MPLS 524334 11 10.202.5.194 20
192.168.48.221/32 sr-te MPLS 716804 8 192.168.48.99 16777215 *
192.168.48.221/32 ldp MPLS 65607 9 10.0.5.185 30
192.168.48.221/32 isis (0) MPLS 524358 11 10.0.5.185 30
192.168.48.223/32 sr-te MPLS 655362 8 10.0.13.184 200
192.168.48.223/32 sr-te MPLS 655363 8 10.0.13.184 200
192.168.48.223/32 sr-te MPLS 655364 8 10.0.5.185 40
192.168.48.223/32 sr-te MPLS 655365 8 10.0.13.184 120
192.168.48.223/32 sr-te MPLS 655366 8 10.0.5.185 120
192.168.48.223/32 sr-te MPLS 655367 8 10.0.13.184 120
192.168.48.223/32 sr-te MPLS 655368 8 10.0.13.184 200
192.168.48.223/32 sr-te MPLS 655369 8 10.0.5.185 40
192.168.48.223/32 sr-te MPLS 716805 8 192.168.48.99 16777215 *
192.168.48.223/32 ldp MPLS 65603 9 10.0.5.185 20
192.168.48.223/32 isis (0) MPLS 524306 11 10.0.5.185 20
192.168.48.224/32 ldp MPLS 65604 9 10.0.5.185 30
192.168.48.224/32 isis (0) MPLS 524361 11 10.0.5.185 30
192.168.48.226/32 isis (0) MPLS 524365 11 11.0.1.2 65534
-------------------------------------------------------------------------------
Flags: B = BGP backup route available
E = inactive best-external BGP route
===============================================================================
The details of the path of one of the SR-TE auto-LSPs now show the ERO transiting through the anycast SID of router Houston 185. See lines marked with an asterisk (*).
*A:Phoenix 199# show router mpls sr-te-lsp "sr-te-level2-mesh-192.168.48.223-
716805" path detail
===============================================================================
MPLS SR-TE LSP sr-te-level2-mesh-192.168.48.223-716805 Path (Detail)
===============================================================================
Legend :
S - Strict L - Loose
A-SID - Adjacency SID N-SID - Node SID
+ - Inherited
===============================================================================
-------------------------------------------------------------------------------
SR-TE LSP sr-te-level2-mesh-192.168.48.223-716805 Path loose-anycast-sid
-------------------------------------------------------------------------------
LSP Name : sr-te-level2-mesh-192.168.48.223-716805
Path LSP ID : 20480
From : 192.168.48.199 To : 192.168.48.223
Admin State : Up Oper State : Up
Path Name : loose-anycast-sid Path Type : Primary
Path Admin : Up Path Oper : Up
Path Up Time : 0d 02:30:28 Path Down Time : 0d 00:00:00
Retry Limit : 0 Retry Timer : 30 sec
Retry Attempt : 1 Next Retry In : 0 sec
CSPF : Enabled Oper CSPF : Enabled
Bandwidth : No Reservation Oper Bandwidth : 0 Mbps
Hop Limit : 255 Oper HopLimit : 255
Setup Priority : 7 Oper Setup Priority : 7
Hold Priority : 0 Oper Hold Priority : 0
Inter-area : N/A
PCE Updt ID : 0 PCE Updt State : None
PCE Upd Fail Code: noError
PCE Report : Enabled Oper PCE Report : Disabled
PCE Control : Disabled Oper PCE Control : Disabled
PCE Compute : Disabled
Include Groups : Oper Include Groups :
None None
Exclude Groups : Oper Exclude Groups :
None None
IGP/TE Metric : 16777215 Oper Metric : 16777215
Oper MTU : 1492 Path Trans : 1
Failure Code : noError
Failure Node : n/a
Explicit Hops :
192.168.48.99(L)
Actual Hops :
192.168.48.99 (192.168.48.185)(N-SID) Record Label : 200099 *
-> 192.168.48.223 (192.168.48.223)(N-SID) Record Label : 200323 *
===============================================================================