ARP/ND Configuration

Configuration Hierarchy

The diagram illustrates the Neighbor Timer configuration hierarchy.

Neighbor Timer Configuration Hierarchy
Figure 1. Neighbor Timer Configuration Hierarchy

Configuration Syntax and Commands

Neighbor Timer Configuration

The following sections describe the interface configuration syntax and commands.

Syntax:

set global neighbor <attribute> <value>

Attribute Description

garp-interval

Gratuitous ARP interval. The value is in seconds.
Range: 1 to 1000 seconds
Default: 60

probe-interval

Neighbor probe interval. The value is in seconds.
Range: 1 to 1000 seconds
Default: 10

ra-interval

Router advertisement interval. The value is in seconds.
Range: 1 to 1000 seconds
Default: 10

scan interval

Neighbor scan interval. The value is in seconds.
Range: 1 to 1000 seconds
Default: 60

throttle-interval

ARP throttle interval. The value is in seconds.
Range: 1 to 1000 seconds
Default: 10

Example: Neighbor timer Configuration

{
    "rtbrick-config:neighbor": {
      "garp-interval": 10,
      "probe-interval": 120,
      "scan-interval": 120,
      "throttle-interval": 120,
      "ra-interval": 120
    }
  }

Static IP Neighbor Configuration

This section describes configuration options at static IP neighbors.

Syntax:

set interface <interface-name> unit <unit-id> neighbor <attribute> <value>

Attribute Description

<interface-name>

Name of the interface. Examples: ifp-0/0/1.

<unit-id>

Create a logical interface (also referred to as a sub-interface) under the physical interface.

IPv4/IPv6 <ip-address>

Neighbor IPv4 or IPv6 address.

MAC <mac-address>

Neighbor MAC address.

Example: Static IP Neighbor Configuration

supervisor@rtbrick>LEAF01: cfg> show config
{
  "data": {
    "rtbrick-config:interface": [
      {
        "name": "ifp-0/1/5",
        "unit": [
          {
            "unit-id": 1,
            "neighbor": {
              "ipv4": [
                {
                  "address4": "198.51.100.10",
                  "mac": "11:11:11:11:11:11"
                }
              ]
            }
          }
        ]
      }
    ]
  }
}

Disabling Gratuitous ARP on Interface

You can disable the sending of Gratuitous ARP (GARP) on an interface, which is enabled by default on all interfaces.

To enable GARP on an interface, you need to delete the garp-disable true configuration.

Syntax:

set interface <interface-name> unit <unit-id> garp-disable true

Attribute Description

interface <interface-name>

Name of the interface. Examples: ifp-0/0/1.

garp-disable true

Disables Gratuitous ARP (GARP). Default is GARP enabled.

Example: Disabling Gratuitous ARP

supervisor@rtbrick.net: cfg> set interface ifp-0/0/0 unit 100 garp-disable true

Enabling Permanent ARP Entry on IFLs

You can enable the Permanent ARP Entry on IFLs functionality.

Syntax:

set interface <interface> unit <unit id> neighbor < ipv4 | ipv6 > <ip address> dynamic true

Attribute Description

<interface-name>

Name of the interface. Example: ifp-0/0/1.

<unit-id>

Create a logical interface (also referred to as a sub-interface) under the physical interface.

neighbor IPv4/IPv6 <ip-address>

Neighbor IPv4 or IPv6 address.

dynamic

Dynamic resolution mode.

Example: Enable Permanent ARP Entry on IFLs

{
  "ietf-restconf:data": {
    "rtbrick-config:interface": [
      {
        "name": "ifp-0/0/0",
        "host-if": "S1-1-SN",
        "unit": [
          {
            "unit-id": 10,
            "neighbor": {
              "ipv4": [
                {
                  "address4": "10.2.2.2",
                  "dynamic": "true"
                }
              ]
            }
          }
        ]
      },
      {
        "name": "ifp-0/0/1",
        "host-if": "S1-2-SN"
      },
      {
        "name": "ifp-0/0/2",
        "host-if": "S1-3-L1"
      },
      {
        "name": "ifp-0/0/3",
        "host-if": "S1-4-L1"
      }
    ]
  }
}

Host-Path Rate Limiting for Unresolved ARP/ND Traffic

RBFS supports host-path traffic policing for packets generated due to ARP/ND resolution failures for directly connected destinations. When ARP/ND resolution fails, traffic destined for unresolved next hops can be redirected to the control plane, causing excessive host-path load. By default, this feature is enabled with a default policer value of 10Mbps.

Syntax:

set forwarding-options hostpath policer <policer>

Option Description

<policer>

Name of the policer to be applied to the host path.

The following configuration example attaches a specific policer named 'policer-hostpath' to the hostpath to ensure that management and protocol traffic does not overwhelm the processor during traffic spikes.

set forwarding-options hostpath policer policer-hostpath
{
  "forwarding-options": {
    "hostpath": {
      "policer": {
        "policer-name": policer-hostpath
      }
    }
  }
}