ARP/ND User Guide

1. Introduction

RBFS allows you to set the timer information for ARP and ND routes. The timer information specifies how frequently a device sends messages to its neighbor. RBFS provides a logical interface with which you can configure timers for neighbor routers. These timers are essential for protocols such as ARP and ND.

RBFS supports timers for the following attributes:

Gratuitous ARP Interval: The Gratuitous ARP is sent as a broadcast by a node to communicate its IP address to MAC address mapping on the network. The GARP timer enables you to specify the interval time based on which GARP can be communicated.
Neighbor Probe Interval: RBFS allows you to configure the neighbor probe interval for the specified interface. This attribute is used to ensure that the neighbor is available or not.
Router Advertisement Interval: RBFS allows you to configure router advertisement interval. Router advertisement includes route information to show the network hosts that the router is operational. The router sends these messages periodically within a time range specified with minimum and maximum values. The Router Advertisement Interval timer applies only to IPv6.
Neighbor Scan Interval: It specifies the time interval for neighbor router scanning. It scans the ARP table of a neighbor router to determine which IP addresses are active.
ARP Throttle Interval: ARP throttling is a method of rate limiting of ARP packets and it safeguards the router by limiting too many ARP requests triggered by incoming traffic. RBFS allows you to configure the time interval for ARP throttling.

1.1. 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. Configuration

2.1. Configuration Hierarchy

The diagram illustrates the Neighbor Timer configuration hierarchy.

Neighbor Timer Configuration Hierarchy

2.2. Configuration Syntax and Commands

2.2.1. 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

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
    }
  }

2.2.2. 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.

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"
                }
              ]
            }
          }
        ]
      }
    ]
  }
}
supervisor@rtbrick>LEAF01: cfg>

3. Operational Commands

3.1. Show Commands

3.1.1. Neighbor Timer Show Commands

Syntax:

show neighbor <option>

Option	Description
-	Without any option, the commands display the information for all neighbors.
instance <instance_name>	Displays summary of the specified neighbor instance
<afi>	Displays neighbor summary for the specified address family

Option

Description

Without any option, the commands display the information for all neighbors.

instance <instance_name>

Displays summary of the specified neighbor instance

<afi>

Displays neighbor summary for the specified address family

Example 1: Summary of neighbor

supervisor@rtbrick>LEAF01: op> show neighbor
Instance                MAC Address          Interface             IP Address                Dynamic  Entry Time
default                 e4:ed:7a:8e:d5:9d    ifl-0/0/5/1           2001:db8:0:30::
true     Thu Feb 24 02:23:19

Example 2: Summary of neighbor instance

supervisor@rtbrick>LEAF01: op> show neighbor instance default
Instance                MAC Address          Interface             IP Address                Dynamic  Entry Time
default                 7a:01:bf:60:03:02    ifp-0/2/3/10        2001:db8:0:111::     true     Thu Feb 24 04:57:22
default                 7a:01:bf:60:03:02    ifp-0/2/3/20        2001:db8:0:19::      true     Thu Feb 24 04:57:22

Example 3: Summary of the neighbor for the specified address family

supervisor@rtbrick>LEAF01: op> show neighbor ipv4
  <cr>
  instance              Instance name

supervisor@rtbrick>LEAF01: op> show neighbor ipv6
Instance                MAC Address          Interface             IP Address                Dynamic  Entry Time
default                 7a:01:bf:60:03:02    ifp-0/2/3/10        2001:db8:0:111::    true     Thu Feb 24 04:57:22
default                 7a:01:bf:60:03:02    ifp-0/2/3/20        2001:db8:0:19::     true     Thu Feb 24 04:57:22

Example 4: Summary of the static IP neighbor

supervisor@rtbrick>LEAF01: op> show neighbor
Instance                MAC Address          Interface             IP Address                Dynamic  Entry Time
default                 11:11:11:11:11:11    ifl-0/1/5/1           198.51.100.10                  true     Fri Feb 25 10:13:04

3.1.2. Neighbor Address Resolution

Syntax:

show address resolution <request | response>

Option	Description
Request	Displays the summary of the address resolution request
Response	Displays the summary of address resolution response

Option

Description

Request

Displays the summary of the address resolution request

Response

Displays the summary of address resolution response

Example 1: Summary of the neighbor address resolution request

supervisor@rtbrick>LEAF01: op> show address-resolution request
TableName: global.static.1.address.resolution.request
Next Hop                    AFI         SAFI        Instance
2001:db8:0:30::            ipv6        labeled-un  default

Example 2: Summary of the neighbor address resolution response

supervisor@rtbrick>LEAF01: op> show address-resolution response
TableName: global.static.1.address.resolution.response
IP Address                  Covering Prefix            MAC Address         Interface
2001:db8:0:30::              2001:db8:0:30::/32        e4:ed:7a:8e:d5:9d   ifl-0/0/5/1

©Copyright 2023 RtBrick, Inc. All rights reserved. The information contained herein is subject to change without notice. The trademarks, logos and service marks ("Marks") displayed in this documentation are the property of RtBrick in the United States and other countries. Use of the Marks are subject to RtBrick’s Term of Use Policy, available at https://www.rtbrick.com/privacy. Use of marks belonging to other parties is for informational purposes only.