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1. Introduction

IS-IS, or Intermediate System to Intermediate System, is an open standard routing protocol. ISO published the standard as a way to route datagrams as part of their OSI stack. IETF later republished the standard, and added IP route support.

It is a link-state routing protocol, similar to OSPF. It forms neighbor adjacencies, has areas, exchanges link-state packets, builds a link-state database and runs the Dijkstra SPF algorithm to find the best path to each destination, which is installed in the routing table.

1.1. Segment Routing

IS-IS in RBFS supports segment routing based on RFC 8667. IS-IS segment routing extensions allow to advertise labels with prefixes. RBFS currently supports the following IS-IS segment routing features:

  • MPLS data plane

  • IPv4 prefixes (TLV 135) and IPv6 prefixes (TLV 236)

  • Prefix SID with node flag (Node SID) on loopback interface

  • Anycast SID

  • A single global SRGB block

  • Adjacency SIDs

1.2. IS-IS Flood Filter Configuration

In IS-IS, by default all routers flood link-state packets, so that all routers will have a complete topology view. IS-IS flood filters allow to modify this behaviour and limit the exchange of LSPs. For example, if two spine routers in a spine/leaf fabric are symmetrically connected to two upstream label-switch routers (LSR) like shown in the figure below, you can use a flood filter to not advertise LSPs learned from LSR A back to the LSR B via the second spine switch.

The flooding filter configuration is part of the global configuration hierarchy and therefore you can configure filtering globally, i.e. not per instance, so that the filter configurations can be reused across instances.

flood filter

1.3. Supported Platforms

Not all features are necessarily supported on each hardware platform. Refer to the Platform Guide for the features and the sub-features that are or are not supported by each platform.

2. IS-IS Configuration

2.1. Configuration Hierarchy

The diagram below illustrates the IS-IS configuration hierarchy.

IS-IS Configuration Hierarchy

2.2. Configuration Syntax and Commands

The following sections describe the IS-IS configuration syntax and commands.

2.2.1. Instance Configuration

The instance configuration hierarchy includes parameters that are required for or used by IS-IS.

Syntax:

set instance <instance-name> protocol isis <attribute> <value>

Attribute Description

<name>

Name of the IS-IS instance

area <area>

IS-IS area-address. The area can be represented in 1, 3, 5, 13 bytes format.

authentication <…​>

Specifies the authentication scheme for IS-IS. Refer to section 2.2.1.1 for the IS-IS authentication configuration details.

holding-time <holding-time>

Specifies how long a neighbor should consider this routing device to be operative without receiving another hello packet.

Default value: 30 seconds

Range: 1 through 3,180 seconds

hostname <hostname>

Specifies the hostname mapped to the system identifier.

ignore-attached-bit [true/false]

This configuration allows you to enable the routing device to ignore the attached bit on incoming Level 1 link-state PDUs. If the attached bit is ignored, no default route, which points to the routing device which has set the attached bit, is installed.

interface <…​>

Name of the interface. Refer to section 2.2.2 for the interface configuration details.

ipv6-disable [true/false]

Specifies whether the ipv6-disable configuration is enabled or not. When you set this value to "true", it indicates that IPv6 configuration is disabled.

[level-1/level-2] address-family <…​>

Protocol ISIS level-1/level-2 address-family configuration. Refer to section 2.2.1.2 for the address family configuration details.

lsp-lifetime <lsp-lifetime>

IS-IS link-state PDUs maximum lifetime, default 65535 seconds

multipath <multipath>

Load sharing among multiple ISIS paths, default 256

no-mpls-transit-path [true/false]

When set to true, IS-IS will not install segment routing transit path, default false

overload [true/false]

When set to true, IS-IS overload bit is set, default false

router-id <router-id>

ISIS router identifier (ipv4 format: A.B.C.D)

system-id <system-id>

Specifies the system ID of the device.

Example: IS-IS Instance Configuration

{
    "rtbrick-config:instance": [
      {
        "name": "default",
        "protocol": {
          "isis": {
            "system-id": "1000.9900.0001",
            "overload": "false",
            "holding-time": 100,
            "area": "49.0001/24",
            "hostname": "spine1",
            "router-id": "10.99.0.1",
            "authentication": {
              "level-1": {
                "check": "enable"
              }
            }
          }
        }
      }
    ]
  }
2.2.1.1. IS-IS Authentication Configuration

Syntax:

set instance <instance-name> protocol isis authentication [level-1 | level-2] <attribute> <value>

Attribute Description

check [disable / enable]

Specifies an authentication check to reject PDUs that do not match the type or key requirements. You can enable or disable the authentication check.

key-id1 <key-id1> / key-id2 <key-id2>

The key ID allows you to specify the key identifiers for level-1/level-2 authentication.

key1-encrypted-text <key1-encrypted-text> / key2-encrypted-text <key2-encrypted-text>

Authentication key1 and key 2 encrypted text

key1-plain-text <key1-plain-text> / key2-plain-text <key2-plain-text>

The level-1/level-2 authentication keys specify the authentication keys (passwords) that are used by the neighboring routing devices to verify the authenticity of packets sent from this interface. For the key to work, you also must include the authentication-type statement.

type

Enables you to specify the authentication scheme for IS-IS. If you enable authentication, you must specify a password by including the authentication-key statement.

The following authentication types are supported:

  • clear_text

  • md5

  • sha1

{
  "ietf-restconf:data": {
    "rtbrick-config:instance": [
      {
        "name": "default",
        "protocol": {
          "isis": {
            <...>
            "authentication": {
              "level-1": {
                "type": "md5",
                "key1-encrypted-text": "$239928e897b1f0fb3a97ed426db21aba36ca48479744a7c71255ee2c4e747e859"
              }
            },
            "interface": [
              {
                "name": "ifl-0/0/1/0",
                "type": "point-to-point",
                "level-1": {
                  "snp-authentication": "enable",
                  "hello-authentication": "disable",
                  "metric": 10
                },
                "level-2": {
                  "snp-authentication": "enable",
                  "hello-authentication": "disable",
                  "metric": 10
                }
              },
              <...>
2.2.1.2. IS-IS Address-Family Configuration

The address-family command allows you to enable the address families that IS-IS will route and configure settings that are specific to that address family.

Syntax:

set instance <instance-name> protocol isis [level-1 | level-2] address-family <attribute> <value>

Attribute Description

<afi>

Address family identifier (AFI). Supported values: ipv4, ipv6

<safi>

Subsequent address family identifier (SAFI). Supported values: unicast or labeled-unicast

2.2.1.3. Configuring Route Redistribution

Syntax:

set instance <instance-name> protocol isis [level-1 | level-2] address-family <afi> <safi> redistribute <attribute> <value>

Attribute Description

<afi>

Address family identifier (AFI). Supported values: ipv4, ipv6

<safi>

Subsequent address family identifier (SAFI). Supported values: unicast or labeled-unicast

redistribute <protocol>

Specifies the source from which the routes are to be redistributed from. The available options are bgp, ospf, direct, and static.

redistribute <protocol> <policy>

Specifies the name of the policy map. The redistribute attach point allows routes from other sources to be advertised by IS-IS. Policy can be applied only to the routes that are redistributed from other sources to IS-IS. The support for inter-level leaking through policy is unavailable.

Example: IS-IS address-family configuration

{
    "rtbrick-config:isis": {
      "system-id": "1000.9900.0001",
      "area": "49.0001/24",
      "hostname": "spine1",
      "interface": [
        {
          "name": "ifl-0/0/2/0",
          "type": "point-to-point",
          "level-1": {
            "metric": 1000
          }
        }
      ],
      "level-1": {
        "address-family": [
          {
            "afi": "ipv4",
            "safi": "labeled-unicast",
            "redistribute": [
              {
                "source": "bgp"
                "policy": "filter-link-address"

              }
            ]
          }
        ]
      }
    }
2.2.1.4. Segment Routing Configuration

Syntax:

set instance <instance-name> protocol isis segment-routing <attribute> <value>

Attribute Description

srgb base <srgb base>

Specifies the segment routing global block (SRGB) in source packet routing. SRGB is used for prefix SIDs.
Supported MPLS label values are 0 - 1048575. The reserved MPLS label range is 0 - 15. In RBFS, BGP uses the label range 20000 - 100000. It is recommended to assign label values outside of these reserved ranges to avoid conflicts.

srgb range <srgb range>

IS-IS system range of labels from the base label.

srlb base <srlb base>

Specifies the segment routing local block (SRLB) in source packet routing. SRLB is used for adjacency SIDs.
Supported MPLS label values are 0 - 1048575. The reserved MPLS label range is 0 - 15. In RBFS, BGP uses the label range 20000 - 100000. It is recommended to assign label values outside of these reserved ranges to avoid conflicts.

srlb range <srlb range>

IS-IS system range of labels from the base label.

Example: IS-IS Segment Routing Configuration

{
    "rtbrick-config:isis": {
      segment-routing: {
        "srgb: {
          "base": 5000,
          "range": 1000
        }
        "srlb: {
          "base": 5000,
          "range": 1000,
        }

2.2.2. Configuring IS-IS Interface

By default, there are no interfaces associated with IS-IS. You must configure at least one IS-IS interface for IS-IS adjacency formation.

Syntax:

set instance <instance> protocol isis interface <name> <attribute> <value>

Attribute Description

<name>

Specifies the name of the IS-IS interface.

bfd admin-status [true / false]

Specifies the BFD admin status.

bfd profile <profile>

Specifies the BFD profile name

flood-filter <flood-filter>

Specifies the IS-IS flood filter name

level-1 / level-2

Specify IS-IS interface level configuration. Refer to section 2.2.2.1 for the IS-IS interface level configuration details.

lsp-interval <lsp-interval>

IS-IS system interface LSP interval, default 100

passive [true / false]

Enable interface in passive mode, default false

system-id <system-id>

Interface level system id

type [loopback / none / point-to-point]

Specifies the type of the IS-IS system interface

Example 1: IS-IS Interface Configuration

{
    "rtbrick-config:isis": {
      "interface": [
        {
          "name": "ifl-0/0/1/0",
          "lsp-interval": 200,
          "bfd": {
            "admin-status": "true"
          }
        }
      ]
    }
  }

Example 2: IS-IS Interface Level Flood Filter Configuration

{
    "rtbrick-config:interface": [
      {
        "name": "ifl-0/0/1/0",
        "flood-filter": "spine1_lsr1_flood_filter"
      }
    ]
  }
2.2.2.1. IS-IS Interface Level Configuration

Syntax:

set instance <instance> protocol isis interface <name> [level-1 | level-2] <attribute> <value>

Attribute Description

adjacency-disable [true/false]

Specify the level-1/level-2 adjacency on an interface, default false

hello-authentication [disable/enable]

Authentication on hello packets

metric <metric>

Level-1/Level-2 metric on an interface, default 1000000

snp-authentication [enable/disable]

Authentication on CSNP/PSNP packets

Example: IS-IS Interface Level Configuration

{
    "rtbrick-config:interface": [
      {
        "name": "ifl-0/0/1/0",
        "lsp-interval": 200,
        "level-1": {
          "snp-authentication": "enable",
          "hello-authentication": "enable",
          "metric": 1000,
          "adjacency-disable": "false"
        }
      }
    ]
  }
2.2.2.2. Interface-level Segment Routing Configuration

Syntax:

set instance <instance> protocol isis interface <name> segment-routing <attribute> <value>

Attribute Description

segment-routing [ipv4 / ipv6] anycast-index <anycast-index>

Anycast index segment-ID. The prefix SIDs and anycast SIDs are applied on loopback interface only.

segment-routing [ipv4 / ipv6] index <index>

Prefix index segment ID.

segment-routing point-to-point [ipv4 / ipv6] adjacency-index <adjacency-index>

Adjacency index segment-ID. The adjacency SIDs are applied on active IS-IS interfaces on which adjacencies are established.

Example 1: IS-IS Interface Level Segment Routing Configuration for Prefix and Anycast SID

 "rtbrick-config:instance": [
      {
        "name": "default",
        "protocol": {
          "isis": {
            "interface": [
              {
                "name": "lo-0/0/0",
                "segment-routing": {
                  "ipv4": {
                    "index": 100
                  },
                  "ipv6": {
                    "index": 200
                  }
                }
              },
              {
                "name": "lo-0/0/1",
                "segment-routing": {
                  "ipv4": {
                    "anycast-index": 110
                  },
                  "ipv6": {
                    "anycast-index": 210
                  }
                }
              }
            ]
          }
        }
      }
    ]
  }
}

Example 2: IS-IS Interface Level Segment Routing Configuration for Adjacency SID

{
  "rtbrick-config:isis": {
    "interface": [
      {
        "name": "ifp-0/0/1/0",
        "type": "point-to-point",
        "segment-routing": {
          "point-to-point": {
            "ipv4": {
              "adjacency-index": 241
            },
            "ipv6": {
              "adjacency-index": 261
            }
          }
        }
      }
    ]
  }
}

2.2.3. IS-IS Global Configuration

2.2.3.1. IS-IS Flood Filter Configuration

Syntax:

set global protocol isis flood-filter <filter-name> <ordinal> <attribute> <value>

Attribute Description

<filter-name>

Filter-name which binds a flooding filter to an IS-IS interface

<ordinal>

Number to filter rule

action [block/flood]

Action required to flood or not

ordinal-name <ordinal-name>

Name for the filter rule

system-id <system-id>

IS-IS instance system-id

system-id-mask <system-id-mask>

System ID mask on which the filter should match

Example: IS-IS Flood Filter Configuration

{
    "rtbrick-config:flood-filter": [
      {
        "filter-name": "spine1_lsr1_flood_filter",
        "ordinal": 1,
        "ordinal-name": "spine1",
        "system-id": "1920.0100.4001",
        "action": "flood"
      }
    ]
  }

3. Operational Commands

3.1. IS-IS Show Commands

The IS-IS show commands provide detailed information about the IS-IS protocol operation and IS-IS routes.

3.1.1. IS-IS Overview

Syntax:

show isis overview

Option Description

-

Without any option, this command displays a summary of all the IS-IS instances

Example: Summary view of all the IS-IS instances

supervisor@rtbrick>LEAF01: op> show isis overview
Instance: default
  System ID: 1921.6800.1002
  System hostname: No hostname configured
  Areas: 49.0001/24
  Neighbor hold time: 30 sec
  LSP life time: 65535 se
  Overload bit set: False
  SRGB base: not defined
  SRGB range: not defined
  SRGB label values: not defined
  SRLB base: not defined
  SRLB range: not defined
  SRLB label values: not defined
  Authentication: Level 1: none, Level 2: none

3.1.2. IS-IS Interface

Syntax:

show isis interface <option>

Option Description

-

Without any option, this command displays a summary of all the IS-IS interfaces

instance

Displays IS-IS interface information for an instance

statistics

Displays IS-IS interface statistics information

detail

Displays detailed information for all interfaces

Example 1: Summary view of the IS-IS interfaces

supervisor@rtbrick>LEAF01: op> show isis interface
Instance: default
  Interface        	Level   Adjacencies   Metric 	Type             	Passive
  lo-0/0/4/1           	1         	0	1000000   loopback         	True
  memif-0/1/2/12       	1         	0	1000000   point-to-point   	False
  memif-0/1/6/16       	1         	0	1000000   point-to-point   	False

Example 2: Detailed view of the IS-IS Interface

supervisor@rtbrick>LEAF01: op> show isis interface detail
Instance: default
  Interface: lo-0/0/0/0, Level: 1
    Type: loopback, Passive: True
    Metric: 1000000
    Adjacencies: 0
    CNSP: In: 0 Out: 0 Success: 0 Fail: 0
    PSNP: In: 0 Out: 0 Success: 0 Fail: 0
    LSP:  In: 0 Out: 0 Success: 0 Fail: 0 In Purge: 0 In Auth Fail: 0
    IIH:  In: 0 Out: 0
Instance: default
  Interface: hostif-0/0/0/0, Level: 1
    Type: point-to-point, Passive: False
    Metric: 1000000
    Adjacencies: 1
    CNSP: In: 3020 Out: 3020 Success: 3020 Fail: 0
    PSNP: In: 2 Out: 2 Success: 2 Fail: 0
    LSP:  In: 2 Out: 2 Success: 2 Fail: 0 In Purge: 0 In Auth Fail: 0
    IIH:  In: 5589 Out: 5600
supervisor@S1-STD-7-7001>bm01-tst.fsn.rtbrick.net: op>

Example 3: Summary view of the IS-IS interfaces for a specific instance

supervisor@rtbrick>LEAF01: op>  show isis interface instance default
Instance: default
  Interface        	Level   Adjacencies   Metric 	Type             	Passive
  lo-0/0/4/1           	1         	0	1000000   loopback         	True
  memif-0/1/2/12       	1         	0	1000000   point-to-point   	False
  memif-0/1/6/16       	1         	0	1000000   point-to-point   	False

Example 4: Summary view of the IS-IS interfaces for a specific interface

supervisor@rtbrick>LEAF01: op> show isis interface memif-0/1/6/16
Instance: default
  Interface: memif-0/1/6/16, Level: 1
	Type: point-to-point, Passive: False
	Metric: 1000000
	Adjacencies: 1
	CNSP: In: 24 Out: 34 Success: 24 Fail: 0
	PSNP: In: 8 Out: 10 Success: 5 Fail: 1
	LSP:  In: 14 Out: 11 Success: 11 Fail: 2 In Purge: 0 In Auth Fail: 2
	IIH:  In: 121 Out: 163

Example 5: Summary view of the IS-IS interface statistics

supervisor@rtbrick>LEAF01: op> show isis interface statistics
Instance: default
  Interface    	Level  CSNP In  CSNP Out  CSNP Fail  PSNP In  PSNP Out  PSNP Fail  LSP In  LSP Out  LSP Fail  IIH In  IIH Out
  lo-0/0/4/1       	1    	0     	0      	0    	0     	0      	0   	0    	0     	0   	0    	0
  memif-0/1/2/12   	1   	32    	32      	0    	9     	6      	1   	9   	10     	0 	117  	138
  memif-0/1/6/16   	1   	22    	32      	0    	6     	6      	1   	9    	8     	0 	115  	138
supervisor@rtbrick>LEAF01: op>

3.1.3. IS-IS Neighbor

Syntax:

show isis neighbor <option>

Option Description

-

Without any option, this command displays a summary of all the IS-IS neighbors

detail

Displays detailed information for IS-IS neighbor

instance

Displays IS-IS neighbor information for an instance

Example 1: Summary view of the IS-IS neighbor

supervisor@rtbrick>LEAF01: op> show isis neighbor
Instance: default
  Interface      	System         	Level   State   Type	Up since            	Expires
  memif-0/1/2/12 	1920.0100.4002.00  L1  	Up  	P2P 	Mon Nov 02 06:18:36 	in 28s 228094us
  memif-0/1/6/16 	1920.0000.0006.00  L1  	Up  	P2P 	Mon Nov 02 06:18:30 	in 24s 420225us

Example 2: Detailed view of the IS-IS neighbor

supervisor@rtbrick>LEAF01: op> show isis neighbor detail
Instance: ip2vrf
  System: isr6, Interface: hostif-0/0/2/0
    State: Up, Level: L1, Adjacency type: P2P
    Holding time: 30.0s, Expiry time: in 25s 332949us
    Local IPv4 address: 16.0.1.1, Remote IPv4 address: 16.0.1.6
    Local IPv6 address: fe80::7846:27ff:fec0:2, Remote IPv6 address: fe80::7816:69ff:fec0:0
    IPv4 Adjacency SID: 11116, IPv6 Adjacency SID: 11117
    Up since: Wed Feb 16 04:46:25 GMT +0000 2022, Last down reason: Admin reset
    Last transition: 2022-02-16T04:46:25.300144+0000, Number of transitions: 14
    Error counters:
      Level mismatch: 0, Area mismatch: 0, System ID: 0, Subnet mismatch: 0
      Hold timeout: 3, Neighbor down: 0, Interface down: 0, Admin reset: 1
      Interface configuration: 0, Area configuration: 0, Other: 0

Example 3: Summary view of the IS-IS neighbor for the specified instance

supervisor@rtbrick>LEAF01: op> show isis neighbor instance default
Instance: default
  Interface      	System         	Level   State   Type	Up since            	Expires
  memif-0/1/2/12 	1920.0100.4002.00  L1  	Up  	P2P 	Mon Nov 02 06:18:36 	in 28s 678329us
  memif-0/1/6/16 	1920.0000.0006.00  L1  	Up  	P2P 	Mon Nov 02 06:18:30 	in 28s 88085us
supervisor@rtbrick>LEAF01: op>

Example 4: Detailed view of the IS-IS neighbor for the specified instance

supervisor@rtbrick>LEAF01: op> show isis neighbor instance default detail
Instance: default
  System: 1920.0100.4002.00, Interface: memif-0/1/2/12
	State: Up, Level: L1, Adjacency type: P2P
	Holding time: 30.0s, Expiry time: in 21s 706586us
	Local IPv4 address: 10.4.12.0, Remote IPv4 address: 10.4.12.1
	Local IPv6 address: fe80::7801:49ff:fe60:102, Remote IPv6 address: fe80::7816:7bff:fe60:201
	Up since: Mon Nov 02 06:18:36 GMT +0000 2020, Last down reason: NA
	Last transition: 2020-11-02T06:18:36.947601+0000, Number of transitions: 2
	Error counters:
  	Level mismatch: 0, Area mismatch: 0, System ID: 0, Subnet mismatch: 0
  	Hold timeout: 0, Neighbor down: 0, Interface down: 0, Admin reset: 0
  	Interface configuration: 0, Area configuration: 0, Other: 0
  System: 1920.0000.0006.00, Interface: memif-0/1/6/16
	State: Up, Level: L1, Adjacency type: P2P
	Holding time: 30.0s, Expiry time: in 22s 832756us
	Local IPv4 address: 10.0.16.0, Remote IPv4 address: 10.0.16.1
	Local IPv6 address: fe80::7801:49ff:fe60:106, Remote IPv6 address: fe80::785c:e4ff:fe60:601
	Up since: Mon Nov 02 06:18:30 GMT +0000 2020, Last down reason: NA
	Last transition: 2020-11-02T06:18:30.356111+0000, Number of transitions: 2
	Error counters:
  	Level mismatch: 0, Area mismatch: 0, System ID: 0, Subnet mismatch: 0
  	Hold timeout: 0, Neighbor down: 0, Interface down: 0, Admin reset: 0
  	Interface configuration: 0, Area configuration: 0, Other: 0
supervisor@rtbrick>LEAF01: op>

3.1.4. IS-IS Hostname

Syntax:

show isis hostname

Option Description

-

Without any option, this command displays a summary of all the IS-IS dynamic hostnames

Example: Summary view of IS-IS hostnames

supervisor@rtbrick>LEAF01: op> show isis hostname
Instance   	System-ID       	Hostname
default     	1920.0100.4001  	spine1
supervisor@rtbrick>LEAF01: op>

3.1.5. IS-IS Database

Syntax:

show isis database <option>

Option Description

-

Without any option, this command displays all the IS-IS databases

detail

Displays detailed information for IS-IS database

instance

Displays IS-IS database information for an instance

lsp <lsp-id>

Displays a summary of IS-IS database for the specified LSP ID. This command includes an option for entering the system ID part either by hostname or by ID.

[level-1/level-2] lsp

Displays a summary of IS-IS database LSP information for specified level

system <system-id>

Displays a summary of IS-IS database for all LSPs from a system

[level-1/level-2] system

Displays a summary of IS-IS database for all LSPs from a system on the specified level.

[level-1/level-2] detail

Displays detailed information for the specified level

Example 1: Summary view of the IS-IS Database

supervisor@rtbrick>LEAF01: op> show isis database
Instance: default, Level: 1
  LSP ID                            Sequence     Checksum     Lifetime     Overload     Attached
  1921.6800.1002.00-00           0x3          0x9561         65535            0            0
  1921.6800.1005.00-00           0x2          0x499b         65535            0            0
Instance: default, Level: 2
  LSP ID                             Sequence     Checksum     Lifetime     Overload     Attached
  1921.6800.1002.00-00           0x4           0x531a        65535             0           0

Example 2: Summary view of the IS-IS database for the specified LSP

supervisor@rtbrick>LEAF01: op> show isis database lsp 1920.0100.4001.00-00
Instance: default, Level: 1
  LSP ID: 1920.0100.4001.00-00
	Interface:
	LSP Header:
  	Sequence: 0xc
  	Checksum: 0x9c74
  	Remaining lifetime: 65535 seconds
  	Flags: Attached: 0, Overload: 0
	Packet:
  	Length: 168 bytes
  	Last received time: 2020-11-02T06:46:46.473726+0000
  	Expiry: expires in 17h 52m 34s 950743us
	Dynamic Hostname TLV: spine1
	Protocols Supported TLVs:
  	Network layer protocol ID: IPv6
  	Network layer protocol ID: IPv4
	Area Address TLVs:
  	Area address: 49.0001
	Authentication TLV:
  	Value: 77b259cb36930819b0abb6120ceee2fd
	IS Reachability TLVs:
  	IS neighbor: 1920.0000.0006.00
  	IS neighbor: 1920.0100.4002.00
	IPv4 Reachability TLVs:
  	IPv4 prefix: 10.0.16.0/31               	Metric:  1000000   Internal   Up
  	IPv4 prefix: 10.4.12.0/31               	Metric:  1000000   Internal   Up
  	IPv4 prefix: 192.1.4.1/32               	Metric:  1000000   Internal   Up 	SID:	1   Flags: Node
	IPv6 Reachability TLVs:
  	IPv6 prefix: 192:1:4::1/128             	Metric:  1000000   Internal   Up
   Segment Routing TLVs:
  	SRGB: Base: 10000, Range: 2000
Instance: default, Level: 2
  LSP ID: 1920.0100.4001.00-00
	Interface:
	LSP Header:
  	Sequence: 0x12
  	Checksum: 0x6407
  	Remaining lifetime: 65535 seconds
  	Flags: Attached: 0, Overload: 0
	Packet:
  	Length: 247 bytes
  	Last received time: 2020-11-02T06:47:06.466723+0000
  	Expiry: expires in 17h 52m 54s 889789us
	Dynamic Hostname TLV: spine1
	Protocols Supported TLVs:
  	Network layer protocol ID: IPv6
  	Network layer protocol ID: IPv4
	Area Address TLVs:
  	Area address: 49.0001
	Authentication TLV:
  	none
	IS Reachability TLVs:
	IPv4 Reachability TLVs:
  	IPv4 prefix: 10.0.16.0/31               	Metric:  1000000   Internal   Up
  	IPv4 prefix: 10.0.27.0/31               	Metric:  2000000   Internal   Up
  	IPv4 prefix: 10.0.68.0/31               	Metric:  2000000   Internal   Up
  	IPv4 prefix: 10.0.69.0/31               	Metric:  2000000   Internal   Up
  	IPv4 prefix: 10.4.12.0/31               	Metric:  1000000   Internal   Up
  	IPv4 prefix: 192.0.0.6/32               	Metric:  2000000   Internal   Up 	SID:	6   Flags: Re-advertisement, Node
  	IPv4 prefix: 192.1.4.1/32               	Metric:  1000000   Internal   Up 	SID:	1   Flags: Re-advertisement, Node
  	IPv4 prefix: 192.1.4.2/32               	Metric:  2000000   Internal   Up 	SID:	2   Flags: Re-advertisement, Node
	IPv6 Reachability TLVs:
  	IPv6 prefix: 192:1:4::1/128             	Metric:  1000000   Internal   Up
  	IPv6 prefix: 192:1:4::2/128             	Metric:  2000000   Internal   Up
   Segment Routing TLVs:
  	SRGB: Base: 10000, Range: 2000
supervisor@rtbrick>LEAF01: op>

Example 3: Detailed view of the IS-IS database for level-1

supervisor@rtbrick>LEAF01: op> show isis database level-1 detail
Instance: default, Level: 1
  LSP ID: 1920.0100.4001.00-00
	Interface:
	LSP Header:
  	Sequence: 0xc
  	Checksum: 0x9c74
  	Remaining lifetime: 65535 seconds
  	Flags: Attached: 0, Overload: 0
	Packet:
  	Length: 168 bytes
  	Last received time: 2020-11-02T06:46:46.473726+0000
  	Expiry: expires in 17h 50m 31s 759013us
	Dynamic Hostname TLV: spine1
	Protocols Supported TLVs:
  	Network layer protocol ID: IPv6
  	Network layer protocol ID: IPv4
	Area Address TLVs:
  	Area address: 49.0001
	Authentication TLV:
  	Value: 77b259cb36930819b0abb6120ceee2fd
	IS Reachability TLVs:
  	IS neighbor: 1920.0000.0006.00
  	IS neighbor: 1920.0100.4002.00
	IPv4 Reachability TLVs:
  	IPv4 prefix: 10.0.16.0/31               	Metric:  1000000   Internal   Up
  	IPv4 prefix: 10.4.12.0/31               	Metric:  1000000   Internal   Up
  	IPv4 prefix: 192.1.4.1/32               	Metric:  1000000   Internal   Up 	SID:	1   Flags: Node
	IPv6 Reachability TLVs:
  	IPv6 prefix: 192:1:4::1/128             	Metric:  1000000   Internal   Up
   Segment Routing TLVs:
  	SRGB: Base: 10000, Range: 2000
  LSP ID: 1920.0100.4002.00-00
	Interface: memif-0/1/2/12
	LSP Header:
  	Sequence: 0x9
  	Checksum: 0x89a6
  	Remaining lifetime: 65534 seconds
  	Flags: Attached: 0, Overload: 0
	Packet:
  	Length: 149 bytes
  	Last received time: 2020-11-02T06:45:59.814186+0000
  	Expiry: expires in 17h 49m 44s 99010us
	Dynamic Hostname TLV: none
	Protocols Supported TLVs:
  	Network layer protocol ID: IPv6
  	Network layer protocol ID: IPv4
	Area Address TLVs:
  	Area address: 49.0001
	Authentication TLV:
  	Value: 5892f2d37d7f23abcfcb48466276659c
	IS Reachability TLVs:
  	IS neighbor: 1920.0100.4001.00
	IPv4 Reachability TLVs:
  	IPv4 prefix: 10.0.27.0/31               	Metric:  1000000   Internal   Up
  	IPv4 prefix: 10.4.12.0/31               	Metric:  1000000   Internal   Up
  	IPv4 prefix: 192.1.4.2/32               	Metric:  1000000   Internal   Up 	SID:	2   Flags: Node
	IPv6 Reachability TLVs:
  	IPv6 prefix: 192:1:4::2/128             	Metric:  1000000   Internal   Up
   Segment Routing TLVs:
  	SRGB: Base: 70000, Range: 2000
supervisor@rtbrick>LEAF01: op>

Example 4: Summary view of the IS-IS database for the specified instance

supervisor@rtbrick>LEAF01: op> show isis database instance default
Instance: default, Level: 1
  LSP ID                            Sequence     Checksum     Lifetime     Overload     Attached
  1921.6800.1002.00-00           0x3          0x9561        65535            0            0
  1921.6800.1005.00-00           0x2          0x499b        65535            0            0
Instance: default, Level: 2
  LSP ID                            Sequence     Checksum     Lifetime     Overload     Attached
  1921.6800.1002.00-00           0x4          0x531a        65535            0            0

Example 5: Summary view of the IS-IS database for the specified instance and LSP

supervisor@rtbrick>LEAF01: op> show isis database instance default lsp 1920.0100.4001.00-00
Instance: default, Level: 1
  LSP ID: 1920.0100.4001.00-00
	Interface:
	LSP Header:
  	Sequence: 0xc
  	Checksum: 0x9c74
  	Remaining lifetime: 65535 seconds
  	Flags: Attached: 0, Overload: 0
	Packet:
  	Length: 168 bytes
  	Last received time: 2020-11-02T06:46:46.473726+0000
  	Expiry: expires in 17h 52m 34s 950743us
	Dynamic Hostname TLV: spine1
	Protocols Supported TLVs:
  	Network layer protocol ID: IPv6
  	Network layer protocol ID: IPv4
	Area Address TLVs:
  	Area address: 49.0001
	Authentication TLV:
  	Value: 77b259cb36930819b0abb6120ceee2fd
	IS Reachability TLVs:
  	IS neighbor: 1920.0000.0006.00
  	IS neighbor: 1920.0100.4002.00
	IPv4 Reachability TLVs:
  	IPv4 prefix: 10.0.16.0/31               	Metric:  1000000   Internal   Up
  	IPv4 prefix: 10.4.12.0/31               	Metric:  1000000   Internal   Up
  	IPv4 prefix: 192.1.4.1/32               	Metric:  1000000   Internal   Up 	SID:	1   Flags: Node
	IPv6 Reachability TLVs:
  	IPv6 prefix: 192:1:4::1/128             	Metric:  1000000   Internal   Up
   Segment Routing TLVs:
  	SRGB: Base: 10000, Range: 2000
Instance: default, Level: 2
  LSP ID: 1920.0100.4001.00-00
	Interface:
	LSP Header:
  	Sequence: 0x12
  	Checksum: 0x6407
  	Remaining lifetime: 65535 seconds
  	Flags: Attached: 0, Overload: 0
	Packet:
  	Length: 247 bytes
  	Last received time: 2020-11-02T06:47:06.466723+0000
  	Expiry: expires in 17h 52m 54s 889789us
	Dynamic Hostname TLV: spine1
	Protocols Supported TLVs:
  	Network layer protocol ID: IPv6
  	Network layer protocol ID: IPv4
	Area Address TLVs:
  	Area address: 49.0001
	Authentication TLV:
  	none
	IS Reachability TLVs:
	IPv4 Reachability TLVs:
  	IPv4 prefix: 10.0.16.0/31               	Metric:  1000000   Internal   Up
  	IPv4 prefix: 10.0.27.0/31               	Metric:  2000000   Internal   Up
  	IPv4 prefix: 10.0.68.0/31               	Metric:  2000000   Internal   Up
  	IPv4 prefix: 10.0.69.0/31               	Metric:  2000000   Internal   Up
  	IPv4 prefix: 10.4.12.0/31               	Metric:  1000000   Internal   Up
  	IPv4 prefix: 192.0.0.6/32               	Metric:  2000000   Internal   Up 	SID:	6   Flags: Re-advertisement, Node
  	IPv4 prefix: 192.1.4.1/32               	Metric:  1000000   Internal   Up 	SID:	1   Flags: Re-advertisement, Node
  	IPv4 prefix: 192.1.4.2/32               	Metric:  2000000   Internal   Up 	SID:	2   Flags: Re-advertisement, Node
	IPv6 Reachability TLVs:
  	IPv6 prefix: 192:1:4::1/128             	Metric:  1000000   Internal   Up
  	IPv6 prefix: 192:1:4::2/128             	Metric:  2000000   Internal   Up
   Segment Routing TLVs:
  	SRGB: Base: 10000, Range: 2000
supervisor@rtbrick>LEAF01: op>

3.1.6. IS-IS Route

Syntax:

show isis route <option>

Option Description

-

Without any option, this command displays a summary of the IS-IS route information

instance

Displays IS-IS route information for an instance

<afi> <safi>

Routing information for the specified AFI/SAFI. Supported SAFI values are 'unicast' and 'labeled-unicast'.

Example 1: Summary view of the IS-IS routes

supervisor@rtbrick>LEAF01: op> show isis route
Instance: default, AFI: ipv4, SAFI: unicast
  Prefix                	Level   Metric 	Type     	Next Hop              	Interface
  10.0.16.0/31              	1	1000000   Internal 	n/a                   	local
  10.0.27.0/31              	1	2000000   Internal 	10.4.12.1             	memif-0/1/2/12
  10.0.68.0/31              	1	2000000   Internal 	10.0.16.1             	memif-0/1/6/16
  10.0.69.0/31              	1	2000000   Internal 	10.0.16.1             	memif-0/1/6/16
  10.4.12.0/31              	1	1000000   Internal 	n/a                   	local
  192.0.0.6/32              	1	2000000   Internal 	10.0.16.1             	memif-0/1/6/16
  192.1.4.1/32              	1	1000000   Internal 	n/a                   	local
  192.1.4.2/32              	1	2000000   Internal 	10.4.12.1             	memif-0/1/2/12
Instance: default, AFI: ipv4, SAFI: labeled-unicast
  Prefix                	Level   Metric 	SID Index	Next Hop              	Interface        	Label
  192.0.0.6/32              	1	2000000       	6	10.0.16.1             	memif-0/1/6/16   	10006
  192.1.4.2/32              	1	2000000       	2	10.4.12.1             	memif-0/1/2/12   	10002
Instance: default, AFI: ipv6, SAFI: unicast
  Prefix                	Level   Metric 	Type     	Next Hop              	Interface
  192:1:4::1/128            	1	1000000   Internal 	n/a                   	local
  192:1:4::2/128            	1	2000000   Internal 	fe80::7816:7bff:fe60:201  memif-0/1/2/12

Example 2: Summary view of the IS-IS routes for the specified instance

supervisor@rtbrick>LEAF01: op> show isis route instance default
Instance: default, AFI: ipv4, SAFI: unicast
  Prefix                	Level   Metric 	Type     	Next Hop              	Interface
  10.0.16.0/31              	1	1000000   Internal 	n/a                   	local
  10.0.27.0/31              	1	2000000   Internal 	10.4.12.1             	memif-0/1/2/12
  10.0.68.0/31              	1	2000000   Internal 	10.0.16.1             	memif-0/1/6/16
  10.0.69.0/31              	1	2000000   Internal 	10.0.16.1             	memif-0/1/6/16
  10.4.12.0/31              	1	1000000   Internal 	n/a                   	local
  192.0.0.6/32              	1	2000000   Internal 	10.0.16.1             	memif-0/1/6/16
  192.1.4.1/32              	1	1000000   Internal 	n/a                   	local
  192.1.4.2/32              	1	2000000   Internal 	10.4.12.1             	memif-0/1/2/12
Instance: default, AFI: ipv4, SAFI: labeled-unicast
  Prefix                	Level   Metric 	SID Index	Next Hop              	Interface        	Label
  192.0.0.6/32              	1	2000000       	6	10.0.16.1             	memif-0/1/6/16   	10006
  192.1.4.2/32              	1	2000000       	2	10.4.12.1             	memif-0/1/2/12   	10002
Instance: default, AFI: ipv6, SAFI: unicast
  Prefix                	Level   Metric 	Type     	Next Hop              	Interface
  192:1:4::1/128            	1	1000000   Internal 	n/a                   	local
  192:1:4::2/128            	1	2000000   Internal 	fe80::7816:7bff:fe60:201  memif-0/1/2/12

Example 3: Summary view of the IS-IS routes for the specified instance and address family (IPv4 unicast).

supervisor@rtbrick>LEAF01: op> show isis route instance default ipv4 unicast
Instance: default, AFI: ipv4, SAFI: unicast
  Prefix                	Level   Metric 	Type     	Next Hop              	Interface
  10.0.16.0/31              	1	1000000   Internal 	n/a                   	local
  10.0.27.0/31              	1	2000000   Internal 	10.4.12.1             	memif-0/1/2/12
  10.0.68.0/31              	1	2000000   Internal 	10.0.16.1             	memif-0/1/6/16
  10.0.69.0/31              	1	2000000   Internal 	10.0.16.1             	memif-0/1/6/16
  10.4.12.0/31              	1	1000000   Internal 	n/a                   	local
  192.0.0.6/32              	1	2000000   Internal 	10.0.16.1             	memif-0/1/6/16
  192.1.4.1/32              	1	1000000   Internal 	n/a                   	local
  192.1.4.2/32              	1	2000000   Internal 	10.4.12.1             	memif-0/1/2/12
supervisor@rtbrick>LEAF01: op>

Example 4: Summary view of the IS-IS routes for the specified instance and address family (IPv4 labeled-unicast).

supervisor@rtbrick>LEAF01: op> show isis route instance default ipv4 labeled-unicast
Instance: default, AFI: ipv4, SAFI: labeled-unicast
  Prefix                	Level   Metric 	SID Index	Next Hop              	Interface        	Label
  192.0.0.6/32              	1	2000000       	6	10.0.16.1             	memif-0/1/6/16   	10006
  192.1.4.2/32              	1	2000000       	2	10.4.12.1             	memif-0/1/2/12   	10002

Example 5: Summary view of the IS-IS routes for the specified instance and address family (IPv6 unicast).

supervisor@rtbrick>LEAF01: op> show isis route instance default ipv6 unicast
Instance: default, AFI: ipv6, SAFI: unicast
  Prefix                	Level   Metric 	Type     	Next Hop              	Interface
  192:1:4::1/128            	1	1000000   Internal 	n/a                   	local
  192:1:4::2/128            	1	2000000   Internal 	fe80::7816:7bff:fe60:201  memif-0/1/2/12

3.1.7. IS-IS Segment Routing

Syntax:

show isis segment-routing <option>

Option Description

global-block

Displays Segment routing global block (SRGB) information

global-block instance <instance>

Displays Segment routing global block (SRGB) information for the specified instance

label-binding

Displays the IS-IS segment routing label bindings information

label-binding instance <instance>

Displays the IS-IS segment routing label bindings for the specified instance

prefix-segment

Displays the IS-IS prefix segments information

prefix-segment <instance>

Displays the IS-IS prefix segments for the specified instance

adjacency-segment

Displays the IS-IS segment routing adjacency SIDs

Example 1: Summary view of the IS-IS segment routing global block

supervisor@rtbrick>LEAF01: op> show isis segment-routing global-block
Instance: default, Level: 1
  System                    SRGB Base   SRGB Range
  isr1                           1000         1000
  isr2                           2000         1000
  isr5                           5000         1000
  isr6                           6000         1000
Instance: default, Level: 2
  System                    SRGB Base   SRGB Range
  isr2                           2000         1000
  isr3                           3000         1000
  isr4                           4000         1000
  isr5                           5000         1000

Example 2: Summary view of the IS-IS segment routing label binding

supervisor@rtbrick>LEAF01: op> show isis segment-routing label-binding
Instance: default, Level: 1
  System                    Prefix                              Range   SID     Flags
  isr1                      10.1.1.0/24                             3      10   None
  isr2                      20.1.1.0/24                             3      20   None
Instance: default, Level: 2
  System                    Prefix                              Range   SID     Flags
  isr2                      10.1.1.0/24                             3      10   Re-advertisement
  isr5                      10.1.1.0/24                             3      10   Re-advertisement
  isr5                      20.1.1.0/24                             3      20   Re-advertisement

Example 3: Summary view of the IS-IS segment routing prefix segment

supervisor@rtbrick>LEAF01: op> show isis segment-routing prefix-segment
Instance: default, Level: 1
  System                    Prefix                                   SID     Flags
  isr1                      192.168.1.1/32                             100   Node
  isr1                      192:168:1::1/128                           102   Node
  isr2                      192.168.1.2/32                             200   Node
  isr2                      192:168:1::2/128                           202   Node
Instance: default, Level: 2
  System                    Prefix                                   SID     Flags
  isr2                      192.168.1.1/32                             100   Re-advertisement, Node
  isr2                      192.168.1.2/32                             200   Node
  isr2                      192.168.1.5/32                             500   Re-advertisement, Node
  isr2                      192.168.1.6/32                             600   Re-advertisement, Node
  isr2                      192:168:1::1/128                           102   Re-advertisement, Node

Example 4: Summary view of the IS-IS segment routing adjacency-segment

supervisor@rtbrick>LEAF01: op> show isis segment-routing adjacency-segment
Instance: ip2vrf, Level: 1
  System                       Label   Flags
  isr1                         11116   Value, Local, Persistent
  isr1                         11117   Ipv6 Encapsulation, Value, Local, Persistent
  isr2                         11112   Value, Local, Persistent
Instance: ip2vrf, Level: 2
  System                       Label   Flags

3.1.8. IS-IS SPF

Syntax:

show isis spf <option>

Option Description

result

Displays a summary of the IS-IS SPF results

result <instance>

Displays a summary of the IS-IS SPF results for the specified instance

result [level-1/level2]

Displays a summary of the IS-IS SPF results for the specified level.

Example 1: Summary view of the IS-IS SPF result

supervisor@rtbrick>LEAF01: op> show isis spf result
Instance: default, Level: 1
  Destination Node          Metric       Neighbor Node         Interface         Nexthop   Address
  1920.0000.0006.00          1000000     1920.0000.0006.00     memif-0/1/6/16    IPv4      10.0.16.1
                                         1920.0000.0006.00     memif-0/1/6/16    IPv6      fe80::785c:e4ff:fe60:601
  1920.0100.4001.00                0                           local
  1920.0100.4002.00          1000000     1920.0100.4002.00     memif-0/1/2/12    IPv6      fe80::7816:7bff:fe60:201
                                         1920.0100.4002.00     memif-0/1/2/12    IPv4      10.4.12.1
Instance: default, Level: 2
  Destination Node          Metric       Neighbor Node         Interface         Nexthop   Address
  1920.0100.4001.00                0                           local
supervisor@rtbrick>LEAF01: op>

Example 2: Summary view of the IS-IS SPF result for level-1

supervisor@rtbrick>LEAF01: op> show isis spf result level-1
Instance: default, Level: 1
  Destination Node      	Metric   	Neighbor Node     	Interface     	Nexthop   Address
  1920.0000.0006.00      	1000000 	1920.0000.0006.00 	memif-0/1/6/16	IPv4  	10.0.16.1
                                     	1920.0000.0006.00 	memif-0/1/6/16	IPv6  	fe80::785c:e4ff:fe60:601
  1920.0100.4001.00            	0                       	local
  1920.0100.4002.00      	1000000 	1920.0100.4002.00 	memif-0/1/2/12	IPv6  	fe80::7816:7bff:fe60:201
                                     	1920.0100.4002.00 	memif-0/1/2/12	IPv4  	10.4.12.1
supervisor@rtbrick>LEAF01: op>

Example 3: Summary view of the IS-IS SPF result for level-2

supervisor@rtbrick>LEAF01: op> show isis spf result level-2
Instance: default, Level: 2
  Destination Node      	Metric   	Neighbor Node     	Interface     	Nexthop   Address
  1920.0100.4001.00            	0                       	local
supervisor@rtbrick>LEAF01: op>

Example 4: Summary view of the IS-IS SPF result of a specific instance for level-1

supervisor@rtbrick>LEAF01: op> show isis spf result instance default level-1
Instance: default, Level: 1
  Destination Node      	Metric   	Neighbor Node     	Interface     	Nexthop   Address
  1920.0000.0006.00      	1000000 	1920.0000.0006.00 	memif-0/1/6/16	IPv4  	10.0.16.1
                                     	1920.0000.0006.00 	memif-0/1/6/16	IPv6  	fe80::785c:e4ff:fe60:601
  1920.0100.4001.00            	0                       	local
  1920.0100.4002.00      	1000000 	1920.0100.4002.00 	memif-0/1/2/12	IPv6  	fe80::7816:7bff:fe60:201
                                     	1920.0100.4002.00 	memif-0/1/2/12	IPv4  	10.4.12.1
supervisor@rtbrick>LEAF01: op>

Example 5: Summary view of the IS-IS SPF result of a specific instance for level-2

supervisor@rtbrick>LEAF01: op> show isis spf result instance default level-2
Instance: default, Level: 2
  Destination Node      	Metric   	Neighbor Node     	Interface     	Nexthop   Address
  1920.0100.4001.00            	0                       	local
supervisor@rtbrick>LEAF01: op>

3.2. IS-IS Clear Commands

Clear commands allow to reset operational states.

3.2.1. IS-IS Interface

Syntax:

clear isis interface <option> …​

Option Description

statistics

Clears the statistics of all IS-IS interfaces.

Example: The example below shows how to clear IS-IS interface statistics.

supervisor@rtbrick>LEAF01: op> clear isis interface statistics

3.2.2. IS-IS Neighbor

Syntax:

clear isis neighbor <option> …​

Option Description

neighbor

Clears neighbors of the default instance

neighbor instance <instance_name>

Clears neighbors of the specified instance

neighbor instance <instance_name> interface <interface-name>

Clears the specified interface of a specified neighbor instance

Example: The example below shows how to clear neighbors of the specified instance

supervisor@rtbrick>LEAF01: op> clear isis neighbor instance default

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