The IDEAL (Seamless MPLS) solution allows for large-scale dynamic networking, lowering performance requirements on caseshaped devices and reducing pressure on aggregation devices.
Interior Gateway Protocol (IGP) can be deployed in two modes: IS-IS multi-processes and OSPF multi-areas. This document uses the IS-IS multi-processes as an example.
This chapter describes how to configure different IS-IS processes.
Objectives
After completing this course, you will be able to:
Design and deploy ISIS protocol for ATN+CX network. Configure different IS-IS processes.
Contents 1. IS-IS Deployment Solution 2. Configuration Principle 3. Data Planning 4. Checking the Configurations
Contents 1. IS-IS Deployment Solution 2. Configuration Principle 3. Data Planning 4. Checking the Configurations
Network diagram of the IS-IS multiprocess solution AS 100 CSG1
AS 200 ASBR1
ASG3
ASBR3
Cost 10
MASG1 Cost 10
Cost 100
0 0 1 t s o C
IS-IS 1 L2
0 0 0 2 t s o C
0 1 t s o C
5 2 t s o C
0 1 t s o C
IS-IS 1000 L2
Cost 10
Cost 100 CSG2
IS-IS 100 L2
ASG4
5 2 t s o C
SGW/MME
Cost 10 ASBR2
ASBR4
MASG2
ISIS interface of Access ISIS interface of Aggregation ISIS interface of Core
Contents 1. IS-IS Deployment Solution 2. Configuration Principle 3. Data Planning 4. Checking the Configurations
Flowchart for configuring multi-process IS-IS The access layer and the aggregation layer 1. Enable IS-IS for routers in the access ring and configure IS-IS process 1 to advertise Level-2 routes. 2. Enable IS-IS for routers in the aggregation ring and configure IS-IS process 100 to advertise Level-2 routes. 3. Enable NSR on routers in the aggregation area. 4. Configure interface IP addresses and loopback interface addresses for devices in the access and aggregation areas. 5. Enable IS-IS and set the cost value for all interfaces in the access and aggregation areas. 6. Deploy BFD for IS-IS network-wide to accelerate IS-IS convergence. 7. Configure loopback interface addresses on ASGs and configure the ASGs to advertise the loopback interface addresses to the access area.
Flowchart for configuring multi-process IS-IS The core layer 1. Enable IS-IS for routers in the core area and configure IS-IS process 1000 to advertise Level-2 routes. 2. Enable NSR on routers in the aggregation area. 3. Configure interface IP addresses and loopback interface addresses for devices 4. Enable IS-IS and set the cost value for all interfaces 5. Deploy BFD for IS-IS network-wide to accelerate IS-IS convergence.
Contents 1. IS-IS Deployment Solution 2. Configuration Principle 3. Data Planning 4. Checking the Configurations
IS-IS parameters Introduction Parameter
Value
Remarks
Access layer: 1 IS-IS process ID Aggregation layer: 100
A Network Entity Title (NET) is set. CAUTION The system ID must be unique on the entire network. Obtain the system ID using the IP address of the loopback0 interface. The NETs must be unique. If a NET is not unique, route flapping may occur.
IS-IS parameters Introduction Parameter
Value
Remarks
is-level
Level-2
The level of the router is configured.
cost-style
Wide
Routes with the cost style as wide are received or advertised.
is-name
Same as the device name, for example, isname is set to ASG3 for ASG3.
A dynamic host name is configured for the IS-IS process.
The cost of links on the access ring except links between ASGs is set to 100. The cost of links between ASGs on the access ring is set to 2000. isis cost
The cost of links between ASBRs on the aggregation ring is set to 25 and the cost of other links on the aggregation ring is set to 10. The cost of links between MASGs on the core ring is set to 25 and the cost of other links on the core ring is set to 10.
Link costs are specified for SPF calculation.
IS-IS parameters Introduction Parameter
Value
Remarks The maximum delay is set to 1s, the initial delay to 50 ms, and the incremental delay to 50 ms for SPF calculation. The maximum delay is set to 1s, the initial delay to 50 ms, and the incremental delay to 50 ms for generating an LSP.
timer spf
1 50 50
timer lsp-generation
1 50 50
flash-flood
level-2
The LSP fast flooding function is enabled to accelerate the convergence of an IS-IS network.。
set-overload onstartup
-
Set IS-IS processes to be in the overload state when IS-IS processes start up.
set-overload onstartup allow external
Configured on ASGs.
Allows IP prefixes learned from other protocols to be advertised when allow is configured.
bfd all-interfaces enable
-
Enable BFD for IS-IS.
Contents 1. IS-IS Deployment Solution 2. Configuration Principle 3. Data Planning 4. Checking the Configurations
Checking procedure 1. Run the display isis peer [ verbose ] [ process-id | vpn-instance vpn-instancename ] command to check information about IS-IS neighbors. 2. Run the display isis interface [ verbose ] [ process-id | vpn-instance vpn-instancename ] command to check information about IS-IS interfaces. 3. Run the display isis lsdb [ { level-1 | level-2 } | verbose | { local | lsp-id | is-name symbolic-name } ] * [ process-id | vpn-instance vpn-instance-name ] command to check information in the IS-IS LSDB. 4. Run the display isis route [ process-id | vpn-instance vpn-instance-name ] [ ipv4 ] [ verbose | [ level-1 | level-2 ] | ip-address [ mask | mask-length ] ] * command to check information about IS-IS routes.
Summary 1. IS-IS multi-process Design and Deployment on ATN + CX Network 2. Configuring IS-IS Protocol Steps
