Configuration

Configuring Connectivity Fault Management

To enable the connectivity fault management feature, you need to configure a CFM session.

Creating a CFM Session

OAM CFM supports both point-to-point and point-to-multipoint sessions.

Syntax:

set oam cfm session <session-name> <attribute> <value>

Attribute	Description
continuity-check-interval	Specify continuity check interval time (in seconds). Supported intervals are: 1s, 10s and 100ms.
interface	Logical interface name.
level	Specify the CFM level. Allowed range: 0 - 7.
local-mep	Specify the local end-point identifier. Range: 1-8191.
maintenance-association	Maintenance association name.
maintenance-domain	Maintenance domain name.
remote-mep	Remote end-point identifier. Range: 1-8191.

Attribute

Description

continuity-check-interval

Specify continuity check interval time (in seconds). Supported intervals are: 1s, 10s and 100ms.

interface

Logical interface name.

level

Specify the CFM level. Allowed range: 0 - 7.

local-mep

Specify the local end-point identifier. Range: 1-8191.

maintenance-association

Maintenance association name.

maintenance-domain

Maintenance domain name.

remote-mep

Remote end-point identifier. Range: 1-8191.

Example 1: Point-to-point CFM session configuration

The following configuration defines two CFM sessions on two different interfaces. The sessions, named CFM_DEFAULT_LINK1 and CFM_DEFAULT_LINK2, use the same maintenance domains and different maintenance associations where the domain level is set to 2. The continuity-check interval is configured at 1 second. The continuity check messages (CCMs) are sent every second to verify the link connectivity.

The local MEP is specified as '1000' for CFM_DEFAULT_LINK1 and '1001' for CFM_DEFAULT_LINK2. The remote MEP values are set to '2000' for CFM_DEFAULT_LINK1 and '2001' for CFM_DEFAULT_LINK2 that indicates the remote endpoint for the link validation.

The local MEPs sends CCM messages every second to the remote MEPs. If no CCMs are received from the remote MEPs until CCM threshold (3.5 * CCM interval), it indicates a link fault and CFM session state is marked down.

set oam cfm session CFM_DEFAULT_LINK1
set oam cfm session CFM_DEFAULT_LINK1 level 2
set oam cfm session CFM_DEFAULT_LINK1 maintenance-domain MD_BNG
set oam cfm session CFM_DEFAULT_LINK1 maintenance-association MA_DEFAULT_100
set oam cfm session CFM_DEFAULT_LINK1 continuity-check-interval 1s
set oam cfm session CFM_DEFAULT_LINK1 local-mep 1000
set oam cfm session CFM_DEFAULT_LINK1 remote-mep 2000
set oam cfm session CFM_DEFAULT_LINK1 interface ifl-0/0/0/100
set oam cfm session CFM_DEFAULT_LINK2
set oam cfm session CFM_DEFAULT_LINK2 level 2
set oam cfm session CFM_DEFAULT_LINK2 maintenance-domain MD_BNG
set oam cfm session CFM_DEFAULT_LINK2 maintenance-association MA_DEFAULT_200
set oam cfm session CFM_DEFAULT_LINK2 continuity-check-interval 1s
set oam cfm session CFM_DEFAULT_LINK2 local-mep 1001
set oam cfm session CFM_DEFAULT_LINK2 remote-mep 2001
set oam cfm session CFM_DEFAULT_LINK2 interface ifl-0/0/1/200

supervisor@rtbrick.net: cfg> show config oam cfm session
{
  "rtbrick-config:session": [
    {
      "name": "CFM_DEFAULT_LINK1",
      "level": 2,
      "maintenance-domain": "MD_BNG",
      "maintenance-association": "MA_DEFAULT_100",
      "continuity-check-interval": "1s",
      "local-mep": 1000,
      "remote-mep": 2000,
      "interface": "ifl-0/0/0/100"
    },
    {
      "name": "CFM_DEFAULT_LINK2",
      "level": 2,
      "maintenance-domain": "MD_BNG",
      "maintenance-association": "MA_DEFAULT_200",
      "continuity-check-interval": "1s",
      "local-mep": 1001,
      "remote-mep": 2001,
      "interface": "ifl-0/0/1/200"
    }
  ]
}

To see related show commands and output, see Show OAM CFM.

Example 2: Point-to-Multipoint CFM Session configuration

The following is an example configuration that shows Point-to-Multipoint CFM sessions on a single interface, that is ifl-0/0/5/0. With this configuration, the interface ifl-0/0/5/0 can run multiple CFM sessions. Each session is configured with a common local MEP (2000) and different remote MEPs (3000 and 4000). It allows the local endpoint to monitor connectivity with multiple remote endpoints on a single interface.

set oam cfm session CFM_R3
set oam cfm session CFM_R3 level 2
set oam cfm session CFM_R3 maintenance-domain BNG
set oam cfm session CFM_R3 maintenance-association MA_BNG
set oam cfm session CFM_R3 continuity-check-interval 1s
set oam cfm session CFM_R3 local-mep 2000
set oam cfm session CFM_R3 remote-mep 3000
set oam cfm session CFM_R3 interface ifl-0/0/5/0
set oam cfm session CFM_R4
set oam cfm session CFM_R4 level 2
set oam cfm session CFM_R4 maintenance-domain BNG
set oam cfm session CFM_R4 maintenance-association MA_BNG
set oam cfm session CFM_R4 continuity-check-interval 1s
set oam cfm session CFM_R4 local-mep 2000
set oam cfm session CFM_R4 remote-mep 4000
set oam cfm session CFM_R4 interface ifl-0/0/5/0

Example:

{
  "rtbrick-config:cfm": {
    "session": [
      {
        "name": "CFM_P2MP_R3",
        "level": 2,
        "maintenance-domain": "BNG",
        "maintenance-association": "MA_BNG",
        "continuity-check-interval": "1s",
        "local-mep": 2000,
        "remote-mep": 3000,
        "interface": "ifl-0/0/5/0"
      },
      {
        "name": "CFM_P2MP_R4",
        "level": 2,
        "maintenance-domain": "BNG",
        "maintenance-association": "MA_BNG",
        "continuity-check-interval": "1s",
        "local-mep": 2000,
        "remote-mep": 4000,
        "interface": "ifl-0/0/5/0"
      }
    ]
  }
}

To see related show commands and output, see Show OAM CFM.

Enabling Nexthop Tracking

You can enable Nexthop tracking using the following commands and options.

Syntax:

set instance <instance-name> oam cfm track <session-name> [nexthop4 | nexthop6] <ip-address>

Attribute	Description
<instance-name>	Name of the instance.
<session>	Specify the session name.
[nexthop4 \| nexthop6]	Specify nexthop4 to trace ipv4 nexthop and specify nexthop6 to track ipv6 nexthop.

Attribute

Description

<instance-name>

Name of the instance.

Specify the session name.

[nexthop4 | nexthop6]

Specify nexthop4 to trace ipv4 nexthop and specify nexthop6 to track ipv6 nexthop.

Example:

The following configuration defines nexthop tracking using CFM sessions. The sessions, CFM_DEFAULT_LINK1 and CFM_DEFAULT_LINK2 are linked to a specific set of next-hop addresses, including both IPv4 and IPv6 addresses. If a CFM session goes down, all the associated next-hops will be considered as unreachable and the routes that uses these next-hops are made unavailable in the forwarding information base.

set instance default oam cfm track CFM_DEFAULT_LINK1
set instance default oam cfm track CFM_DEFAULT_LINK1 nexthop4 12.0.1.2
set instance default oam cfm track CFM_DEFAULT_LINK1 nexthop4 182.168.0.20
set instance default oam cfm track CFM_DEFAULT_LINK1 nexthop6 182:168::20
set instance default oam cfm track CFM_DEFAULT_LINK1 nexthop6 fe80::7810:2
set instance default oam cfm track CFM_DEFAULT_LINK2
set instance default oam cfm track CFM_DEFAULT_LINK2 nexthop4 12.1.1.2
set instance default oam cfm track CFM_DEFAULT_LINK2 nexthop4 182.168.0.20
set instance default oam cfm track CFM_DEFAULT_LINK2 nexthop6 182:168::20
set instance default oam cfm track CFM_DEFAULT_LINK2 nexthop6 fe80::7810:2

supervisor@rtbrick.net: cfg> show config instance default oam cfm
{
  "rtbrick-config:cfm": {
    "track": [
      {
        "session": "CFM_DEFAULT_LINK1",
        "nexthop4": [
          "12.0.1.2",
          "182.168.0.20"
          ],
        "nexthop6": [
          "182:168::20",
          "fe80::7810:2"
          ]
      },
      {
        "session": "CFM_DEFAULT_LINK2",
        "nexthop4": [
          "12.1.1.2",
          "182.168.0.20"
          ],
        "nexthop6": [
          "182:168::20",
          "fe80::7810:2"
          ]
      }
    ]
  }
}