IPv4 Port Based DHCP_SERVER in SONiC

High Level Design Document

Rev 0.1

Table of Contents

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Revision

RevDateAuthorChange Description
0.12023/02/08Yaqiang Zhu, Jing KanInitial version

About this Manual

This document describes the design details of ipv4 port based DHCP server feature. Dynamic Host Configuration Protocol (DHCP) server is used to centrally manage and configure IP addresses of clients dynamically. When server receives requests from DHCP-enabled clients, it would offer information to client about IP address, subnet mask, gateway etc.

Scope

This document describes the high level design details about how ipv4 port based DHCP server works.

Definitions/Abbreviations

Table 1: Abbreviations
AbbreviationFull form
DHCPDynamic Host Configuration Protocol
Table 2: Definitions
DefinitionsDescription
kea-dhcp-serverOpen source DHCP server process distributed by ISC
dhcrelayOpen source DHCP relay process distributed by ISC

Overview

A DHCP Server is a server on network that can automatically provide and assign IP addresses, default gateways and other network parameters to client devices.

Background

We plan to implement built-in DHCP Server in SONiC to assign IPs based on interface index.

Port-based DHCP Server has below advantages:

  1. Relatively more secure and stable, if other no-configured interface requests IP, it will not be assigned.

  2. Assigning IP based on port can quickly complete a self-made network without external information input.

Functional Requirements

  1. SONiC built-in DHCP Server.

  2. Rules to assign IPs based on physical ports.

Configuration and Management Requirements

Configuration of DHCP server feature can be done via:

  • JSON config input

  • SONiC CLI

Design

Design considerations

  • Port based means that client from 1 interface can only obtain ip address from specified ip pool we configured.

  • Currently, we only support enabling dhcp_server per switch, means functionality of dhcp_relay cannot work with functionality dhcp_server. We will add restrictions in CLI to prevent users from configuring dhcp_relay when dhcp_server feature is enabled. Maybe add support in future releases for enabling dhcp_server feature per vlan, means enable dhcp_server in one vlan and enable dhcp_relay in other vlan.

  • This feature requires changes in dhcp_relay container. But in the scenario of disabling dhcp_server feature, dhcp_relay work as previous.

  • For MAC address remove scenario, like Client_A get IP_A from port_1 and then moved to port_2. In current design, client_A would keep using IP_A till lease expired, then it would get another IP from port_2 if we configured. But before this lease expire, other clients connected to port_1 cannot get IP_A. Maybe add monitoring mechanism to check fdb table and lease table, to release outdated lease from kea-dhcp-server side in time.

  • In current design, we do not support reply relayed DHCP packet, maybe support this scenario by appending option 82 in future releases.

Design Overview

We use kea-dhcp-server to reply DHCP request packet. kea-dhcp-server natively supports to assign IPs by mac or contents in DHCP packet (like client id or other options), but in our scenario kea-dhcp-server need to know which interface this packet come from. And SONiC has integrated dhcrelay, which can add interface information to option82 in packet when it relay DHCP packet. So we use it to add interface information.

In our design, dhcp_relay container works on host network mode as before. And dhcp_server container works on bridge network mode, means that it can communicate with switch network only via eth0.

For broadcast packet (discover, request) sent by client, obviously it would be routed to the related DHCP interface. For unicast packet (release), client will get server IP from Option 54 (server identifier) in DHCP reply packet receivced previously. But in our scenario, server identifier is the ip of eth0 inside dhcp_server container (240.127.1.2), packet with this destination IP cannot be routed successfully. So we need to specify that kea-dhcp-server replies DHCP request with Option 54 filled with IP of DHCP interface (which is the downstream interface IP of dhcrelay), to let client take relay as server and send unicast packet to relay, and relay would transfer this packet to the real server.

Belows are sample configurations for dhcrelay and kea-dhcp-server:

  • dhcprelay:

    ./dhcrelay -d -m discard -a %h:%p %P --name-alias-map-file /tmp/port-name-alias-map.txt -id Vlan1000 -iu docker0 240.127.1.2

  • kea-dhcp-server

    {
  "Dhcp4": {
    ...
    "interfaces-config": {
      // Listen on eth0
      "interfaces": ["eth0"]
    },
    "client-classes": [
        {
            // Check sub-options of option82, if circuit-id equals to "hostname:etp1",
            // tag it as "hostname-etp1"
            "name": "hostname-etp1",
            "test": "relay4[1].hex == 'hostname:etp1'"
        }
    ],
    "subnet4": [
      {
        "subnet": "192.168.0.0/24",
        "pools": [
          {
            // Assign ip from this pool for packet tagged as "hostname-etp1"
            "pool": "192.168.0.2 - 192.168.0.2",
            "client-class": "hostname-etp1"
          }
        ],
        "option-data": [
            {
                "name": "dhcp-server-identifier",
                "data": "192.168.0.1"
            }
        ]
      }
    ]
    ...
  }
}

Container

A new container dhcp_server based on debian:bookworm, is created to hold DHCP Server logic. Also, related entry would be added to FEATURE table to control enabled/disabled of this feature like below, and the default state of this feature is disabled

{
  "FEATURE": {
    "dhcp_server": {
      "auto_restart": "enabled",
      "delayed": "False",
      "has_global_scope": "True",
      "has_per_asic_scope": "False",
      "high_mem_alert": "disabled",
      "state": "disabled",
      "support_syslog_rate_limit": "true"
    },
  }
}

DHCP Server Daemon

Generate Config

dhcpservd is to generate configuration file for kea-dhcp-server while DHCP Server config in CONFIG_DB changed, and then send SIGHUP signal to kea-dhcp-server process to let new config take effect.

Update Lease

kea-dhcp-server supports to specify a customize script (/tmp/lease_update.sh) to execute whenever a new DHCP lease is created, or an old one destroyed. We use this script to send signal to dhcpservd to read lease file and update lease table in STATE_DB.

{
  "Dhcp4": {
    "lease-database": {
        "type": "memfile",
        "persist": true,
        "name": "/tmp/kea-lease.csv"
    },
    "hooks-libraries": [
      {
          "library": "/usr/lib/x86_64-linux-gnu/kea/hooks/libdhcp_run_script.so",
          "parameters": {
              "name": "/tmp/lease_update.sh",
              "sync": false
          }
      }
    ]
  }
}

address,hwaddr,client_id,valid_lifetime,expire,subnet_id,fqdn_fwd,fqdn_rev,hostname,state,user_context,pool_id
192.168.0.2,aa:bb:cc:dd:ee:ff,,3600,1694000905,1,0,0,hostname,0,,0
192.168.0.131,aa:aa:cc:dd:ee:ff,,3600,1694000909,1,0,0,hostname,0,,1
192.168.0.131,aa:aa:cc:dd:ee:ff,,0,1693997309,1,0,0,hostname,0,,1
192.168.0.131,aa:aa:cc:dd:ee:ff,,0,1693997309,1,0,0,,2,,1
192.168.0.131,aa:aa:cc:dd:ee:ff,,3600,1694000915,1,0,0,hostname,0,,1
192.168.0.2,aa:bb:cc:dd:ee:ff,,0,1693997305,1,0,0,hostname,0,,0

Customize DHCP Packet Options

We can customize DHCP Packet options per DHCP interface by kea-dhcp-server, all DHCP clients connected to this interface share one configuration, and DHCP server would add DHCP options by config to each DHCP packet sent to client.

{
  "Dhcp4": {
    "subnet4": [
      {
        "option-data": [
            {
                "code": 223,
                "data": "'1,1,1,1,1,1,,1,1,1,1,1'",
                "always-send": true
            }
        ],
      }
    ]
  }
}

Have to be aware of is that below options are not supported to customize, because they are specified by other config or they are critical options.

Option codeName
1Subnet Mask
3Router
51Lease Time
53Message Type
54DHCP Server ID

Currently support text, ipv4-address, uint8, uint16, uint32.

DHCP Relay Daemon

For scenario of dhcp_server feature is enabled, we need a daemon process inside dhcp_relay container to manage dhcrelay processes. dhcprelayd would subcribe VLAN/VLAN_MEMBER/DHCP_SERVER_IPV4* table in config_db, and when dhcp_relay container restart or related config changed, dhcprelayd will kill/start/restart dhcrelay process.

DB Changes

We have two main DB changes:

  • CONFIG_DB change.

  • STATE_DB change.

Config DB

Following table changes would be added in Config DB, including DHCP_SERVER_IPV4 table, DHCP_SERVER_IPV4_RANGE table, DHCP_SERVER_IPV4_PORT table and DHCP_SERVER_IPV4_CUSTOMIZED_OPTIONS table.

These new tables are introduced to specify configuration of DHCP Server.

Below is the sample:

DB Objects

{
  "DHCP_SERVER_IPV4": {
      "Vlan100": {
          "gateway": "100.1.1.1",
          "lease_time": "3600",
          "mode": "PORT",
          "netmask": "255.255.255.0",
          "customized_options": [
              "option60"
          ],
          "state": "enabled"
      }
  },
  "DHCP_SERVER_IPV4_CUSTOMIZED_OPTIONS": {
      "option60": {
          "id": "60",
          "type": "text",
          "value": "dummy_value"
      }
  },
  "DHCP_SERVER_IPV4_RANGE": {
      "range1": {
          "ranges": [
              "100.1.1.3",
              "100.1.1.5"
          ]
      }
  },
  "DHCP_SERVER_IPV4_PORT": {
      "Vlan100|PortChannel0003": {
          "ips": [
              "100.1.1.10"
          ]
      },
      "Vlan100|PortChannel2": {
          "ranges": [
              "range1"
          ]
      }
  },
  "DHCP_SERER_IPV4_IP": {
      "eth0": {
          "ip": "240.127.1.2"
      }
  }
}

Yang Model

[yang][dhcp_server] Add dhcp_server_ipv4 yang model

module sonic-dhcp-server-ipv4 {
    yang-version 1.1;
    namespace "http://github.com/sonic-net/sonic-dhcp-server-ipv4";
    prefix dhcp-server-ipv4;
    import ietf-inet-types {
        prefix inet;
    }
    import sonic-vlan {
        prefix vlan;
    }
    import sonic-port {
        prefix port;
    }
    import sonic-portchannel {
        prefix lag;
    }
    description "DHCP_SERVER_IPV4 YANG module for SONiC OS";
    revision 2023-07-19 {
        description "Initial version";
    }
    container sonic-dhcp-server-ipv4 {
        container DHCP_SERVER_IPV4 {
            description "DHCP_SERVER_IPV4 part of config_db.json";
            list DHCP_SERVER_IPV4_LIST {
                description "DHCP_SERVER_IPV4 list part of config_db.json";
                key "name";
                leaf name {
                    description "Interface name for DHCP server";
                    type leafref {
                        path "/vlan:sonic-vlan/vlan:VLAN/vlan:VLAN_LIST/vlan:name";
                    }
                }
                leaf gateway {
                    description "Gateway IP for DHCP server";
                    mandatory true;
                    type inet:ipv4-address;
                }
                leaf lease_time {
                    description "Lease time of DHCP IP";
                    mandatory true;
                    type uint32 {
                        range "1..4294967295";
                    }
                }
                leaf mode {
                    description "Mode of assigning IP";
                    mandatory true;
                    type string {
                        pattern "PORT" {
                            error-message "Invalid mode for DHCP server";
                            error-app-tag dhcp-server-mode-invalid;
                        }
                    }
                }
                leaf netmask {
                    description "Subnet mask value for DHCP server";
                    mandatory true;
                    type inet:ipv4-address-no-zone;
                }
                leaf-list customized_options {
                    description "Customized options list";
                    type leafref {
                        path "/dhcp-server-ipv4:sonic-dhcp-server-ipv4/dhcp-server-ipv4:DHCP_SERVER_IPV4_CUSTOMIZED_OPTIONS/dhcp-server-ipv4:DHCP_SERVER_IPV4_CUSTOMIZED_OPTIONS_LIST/dhcp-server-ipv4:name";
                    }
                }
                leaf state {
                    description "State of DHCP server";
                    mandatory true;
                    type enumeration {
                        enum enabled;
                        enum disabled;
                    }
                }
            }
            /* end of DHCP_SERVER_IPV4_LIST */
        }
        /* end of DHCP_SERVER_IPV4 container */
        container DHCP_SERVER_IPV4_CUSTOMIZED_OPTIONS {
            description "DHCP_SERVER_IPV4_CUSTOMIZED_OPTIONS part of config_db.json";
            list DHCP_SERVER_IPV4_CUSTOMIZED_OPTIONS_LIST {
                description "DHCP_SERVER_IPV4_CUSTOMIZED_OPTIONS list part of config_db.json";
                key "name";
                leaf name {
                    description "Name of customized option";
                    type string {
                        length 1..255 {
                            error-message "Invalid length for the customized options name";
                        }
                    }
                }
                leaf id {
                    description "Customized PortChannel0003option ID";
                    mandatory true;
                    type uint8 {
                        range "1..254";
                    }
                }
                leaf type {
                    description "Type of customized option";
                    mandatory true;
                    type enumeration {
                        enum text;
                        enum ipv4-address;
                        enum uint8;
                        enum uint16;
                        enum uint32;
                        enum uint64;
                    }
                }
                leaf value {
                    description "Value of customized option";
                    mandatory true;
                    type union {
                        type string {
                            length 0..255;
                        }
                        type inet:ipv4-address;
                        type uint8;
                        type uint16;
                        type uint32;
                        type uint64;
                    }
                }
            }
            /* end of DHCP_SERVER_IPV4_CUSTOMIZED_OPTIONS_LIST */
        }
        /* end of DHCP_SERVER_IPV4_CUSTOMIZED_OPTIONS container */
        container DHCP_SERVER_IPV4_RANGE {
            description "DHCP_SERVER_IPV4_RANGE part of config_db.json";
            list DHCP_SERVER_IPV4_RANGE_LIST {
                description "DHCP_SERVER_IPV4_RANGE list part of config_db.json";
                key "name";
                leaf name {
                    description "Name of IP range";
                    type string {
                        length 1..255 {
                            error-message "Invalid length for the IP range name";
                        }
                    }
                }
                leaf-list ranges {
                    description "Range of IPs";
                    type inet:ipv4-address;
                }
                must "((count(ranges) <= 2) and (count(ranges) >= 1))";
            }
            /* end of DHCP_SERVER_IPV4_RANGE_LIST */
        }
        /* end of DHCP_SERVER_IPV4_RANGE */
        container DHCP_SERVER_IPV4_PORT {
            description "DHCP_SERVER_IPV4_PORT part of config_db.json";
            list DHCP_SERVER_IPV4_PORT_LIST {
                description "DHCP_SERVER_IPV4_PORT list part of config_db.json";
                key "vlan port";
                leaf vlan {
                    description "Name of vlan";
                    type leafref {
                      path "/vlan:sonic-vlan/vlan:VLAN/vlan:VLAN_LIST/vlan:name";
                    }
                }
                leaf port {
                    description "Interface under vlan";
                    type union {
                      type leafref {
                        path "/port:sonic-port/port:PORT/port:PORT_LIST/port:name";
                      }
                      type leafref {
                        path "/lag:sonic-portchannel/lag:PORTCHANNEL/lag:PORTCHANNEL_LIST/lag:name";
                      }
                    }
				        }
                leaf-list ips {
                    description "Assigned IPs";
                    must "(not(boolean(../ranges)))"{
                        error-message "Statement of 'ip' and 'ranges' cannot both exist";
                    }
                    type inet:ipv4-address;
                }
                leaf-list ranges {
                    description "IP ranges";
                    must "(not(boolean(../ip)))"{
                        error-message "Statement of 'ip' and 'ranges' cannot both exist";
                    }
                    type leafref {
                        path "/dhcp-server-ipv4:sonic-dhcp-server-ipv4/dhcp-server-ipv4:DHCP_SERVER_IPV4_RANGE/dhcp-server-ipv4:DHCP_SERVER_IPV4_RANGE_LIST/dhcp-server-ipv4:name";
                    }
                }
            }
            /* end of DHCP_SERVER_IPV4_PORT_LIST */
        }
        /* end of DHCP_SERVER_IPV4_PORT container */
    }
}

State DB

Following table changes would be added in State DB, including DHCP_SERVER_IPV4_LEASE table and DHCP_SERVER_IPV4_SERVER_IP table.

DB Objects

{
  "DHCP_SERVER_IPV4_LEASE": {
    "Vlan1000|10:70:fd:b6:13:00": {
      "lease_start": "1677640581", // Start time of lease, unix time
      "lease_end": "1677641481", // End time of lease
      "ip": "192.168.0.1"
    },
    "Vlan1000|10:70:fd:b6:13:01": {
      "lease_start": "1677640581",
      "lease_end": "1677641481",
      "ip": "192.168.0.2"
    }
  },
  "DHCP_SERVER_IPV4_SERVER_IP": {
    "eth0": {
      "ip": "240.127.1.2"
    }
  }
}

Yang Model

module sonic-dhcp-server-ipv4 {
  import ietf-inet-types {
        prefix inet;
  }
  container sonic-dhcp-server-ipv4 {
    container DHCP_SERVER_IPV4_LEASE {
      description "DHCP_SERVER_IPV4_LEASE part of state_db";
      list DHCP_SERVER_IPV4_LEASE_LIST {
        key "name";
        leaf name {
          type string;
        }
        leaf lease_start {
          description "Unix time of lease start";
          type uint64
        },
        leaf lease_end {
          description "Unix time of lease end";
          type uint64
        }
        leaf ip {
          description "DHCP ip address assigned to this client";
          type inet:ipv4-address
        }
      }
    }
    /* end of container DHCP_SERVER_IPV4_LEASE */
    container DHCP_SERVER_IPV4_SERVER_IP {
      description "DHCP_SERVER_IPV4_SERVER_IP part of state_db";
      list DHCP_SERVER_IPV4_SERVER_IP_list {
        key "name";
        leaf name {
          type string;          
        }
        leaf ip {
          description "IP address of dhcp_server";
          type inet:ipv4-address
        }
      }
    }
  }
  /* end of container sonic-dhcp-server-ipv4 */
}

Flow Diagrams

DHCP Server Flow

This sequence figure describe the work flow for reply DHCP packet.

Config Change Flow

This sequence figure describe the work flow of dhcpservd detect config_db changed CLI.

Lease Update Flow

Below sequence figure describes the work flow how kea-dhcp-server updates lease table while new lease is created.

Start flow of dhcprelayd

This sequence figure describe the work flow of dhcprelayd start. (Under enabled dhcp_server feature)

Work flow of dhcprelayd capture db change

This sequence figure describe the work flow of dhcprelayd capture DHCP_SERVER_IPV4 table change. (Under enabled dhcp_server feature)

CLI

  • config CLI
CLIDescription
config dhcp_server ipv4 (add | del | update)Add or delete or update DHCP server config
config dhcp_server ipv4 (enable | disable)Enable or disable in DHCP server
config dhcp_server ipv4 range (add | del \ update)Add, delete or update DHCP server ip range
config dhcp_server ipv4 ip (bind | unbind)Bind or unbind DHCP server with ip or range
config dhcp_server ipv4 option (add | del)Add or delete customized DHCP option
config dhcp_server ipv4 option (bind | unbind)Bind or unbind DHCP server with option
  • show CLI
CLIDescription
show dhcp_server ipv4 infoShow DHCP server config
show dhcp_server rangeShow ip range
show dhcp_server optionShow customized DHCP options
show dhcp_server leaseShow lease information of DHCP server

Config CLI

config dhcp_server add

This command is used to add dhcp_server for DHCP interface.

  • Usage

    config dhcp_server ipv4 add --mode <mode> [--infer_gw_nm] [--lease_time <lease_time>] [--gateway <gateway>] [--netmask <netmask>] <dhcp_interface>

Options:
   mode: Specify mode of assign IP, currently only support 'PORT'. [required]
   lease_time: Time that the client can lease IP once. [not required, default value is 900(s)]
   infer_gw_nm: Indicate whether to use gateway and netmask of server interface. [not required if gateway and netmask is given]
   gateway: Gateway of DHCP server. [ignored if infer_gw_nm is given]
   netmask: Netmask of DHCP server. [ignored if infer_gw_nm is given]

  • Example

    config dhcp_server ipv4 add --mode PORT --infer_gw_nm --lease_time 300 Vlan1000
config dhcp_server ipv4 add --mode PORT --lease_time 300 --gateway 192.168.0.1 --netmask 255.255.255.0 Vlan1000

config dhcp_server del

This command is used to delete all dhcp_server config for DHCP interface, to be clarify that delete a enable dhcp_server is not allowed.

  • Usage

    config dhcp_server ipv4 del <dhcp_interface>

  • Example

    config dhcp_server ipv4 del Vlan1000

config dhcp_server enable/disable

This command is used to enable or disable dhcp_server for DHCP interface, this state is set to disable by default while adding a new dhcp_server.

  • Usage

    config dhcp_server ipv4 (enable | disable) <dhcp_interface>

  • Example

    config dhcp_server ipv4 enable Vlan1000

config dhcp_server update

This command is used to update dhcp_server config.

  • Usage

    config dhcp_server ipv4 update --mode <mode> [--infer_gw_nm] [--lease_time <lease_time>] [--gateway <gateway>] [--netmask <netmask>] <dhcp_interface>

  • Example

    config dhcp_server ipv4 update --mode PORT --infer_gw_nm --lease_time 300 Vlan1000

config dhcp_server range add/del/update

This command is used to config ip range.

  • Usage

    # <ip_end> is not required, if not given, means ip_end is equal to ip_start
config dhcp_server ipv4 range add <range_name> <ip_start> [<ip_end>]
config dhcp_server ipv4 range update <range_name> <ip_start> [<ip_end>]
config dhcp_server ipv4 range del <range_name>

  • Example

    config dhcp_server ipv4 range add range1 192.168.0.1

config dhcp_server ipv4 range update range1 192.168.0.2

config dhcp_server ipv4 range del range1

config dhcp_server ip bind/unbind

This command is used to config dhcp ip per interface.

  • Usage

    config dhcp_server ipv4 ip bind <vlan_interface> <interface> (--range <ip_range_list> | <ip_list>)
config dhcp_server ipv4 ip unbind <vlan_interface> <interface> (--range <ip_range_list> | <ip_list> | all)

  • Example

    config dhcp_server ipv4 ip bind Vlan1000 Ethernet1 --range range1
config dhcp_server ipv4 ip bind Vlan1000 Ethernet2 192.168.0.5 192.168.0.6
config dhcp_server ipv4 ip unbind Vlan1000 Ethernet1 --range range1 range2

config dhcp_server option add

This command is used to add dhcp option. Type field can refer to Customize DHCP Packet Options.

  • Usage

    config dhcp_server ipv4 option add <option_name> <option_id> [<type>] <value>

  • Example

    config dhcp_server ipv4 option add option_1 12 text host_1

config dhcp_server option del

This command is used to del dhcp option.

  • Usage

    config dhcp_server ipv4 option del <option_name>

  • Example

    config dhcp_server ipv4 option del option_1

config dhcp_server option bind

This command is used to bind dhcp option per dhcp interface.

  • Usage

    config dhcp_server ipv4 option bind <dhcp_interface> <option_list>

  • Example

    config dhcp_server ipv4 option bind Vlan1000 option_1

config dhcp_server option unbind

This command is used to unbind dhcp option.

  • Usage

    config dhcp_server ipv4 option unbind <dhcp_interface> (--all | <option_name>)

  • Exampe

    config dhcp_server ipv4 option unbind Vlan1000 --all

config dhcp_server ipv4 option unbind Vlan1000 option_1

Show CLI

show dhcp_server info

This command is used to show dhcp_server config.

  • Usage

    show dhcp_server ipv4 info [--with_customize_option] [<dhcp_interface>]

  • Example

    show dhcp_server ipv4 info Vlan1000
+-----------+-----+------------+--------------+--------------+---------+
|Interface  |Mode |Gateway     |Netmask       |Lease Time(s) |IP Bind  |
|-----------+-----+------------+--------------+----------- --+---------+
|Vlan1000   |PORT |192.168.0.1 |255.255.255.0 |180           |range_1  |
|           |     |            |              |              |range_2  |
|           |     |            |              |              |range_3  |
+-----------+-----+------------+--------------+--------------+---------+

show dhcp_server ipv4 info --with_customize_option Vlan1000
+-----------+-----+------------+--------------+--------------+---------+-----------------+
|Interface  |Mode |Gateway     |Netmask       |Lease Time(s) |IP Bind  |Customize Option |
|-----------+-----+------------+--------------+----------- --+---------+-----------------+
|Vlan1000   |PORT |192.168.0.1 |255.255.255.0 |180           |range_1  |option_1         |
|           |     |            |              |              |range_2  |option_2         |
|           |     |            |              |              |range_3  |                 |
+-----------+-----+------------+--------------+--------------+---------+-----------------+

show dhcp_server ipv4 info
+-----------+-----+------------+--------------+--------------+------------+
|Interface  |Mode |Gateway     |Netmask       |Lease Time(s) |IP Bind     |
|-----------+-----+------------+--------------+----------- --+------------+
|Vlan1000   |PORT |192.168.0.1 |255.255.255.0 |180           |range_1     |
|           |     |            |              |              |range_2     |
|           |     |            |              |              |range_3     |
+-----------+-----+------------+--------------+--------------+------------+
|Vlan2000   |PORT |192.168.1.1 |255.255.255.0 |180           |192.168.1.2 |
+-----------+-----+------------+--------------+--------------+------------+

show dhcp_server range

This command is used to show dhcp_server ip range.

  • Usage

    show dhcp_server ipv4 range [<range_name>]

  • Example

    show dhcp_server ipv4 range range_1
+-------------+-------------+-------------+---------+
|IP Range Name |IP Start     |IP End       |IP count |
|--------------+-------------+-------------+---------+
|range_1        |192.168.0.5  |192.168.0.10 |6        |
+--------------+-------------+-------------+---------+

show dhcp_server ipv4 range
+--------------+-------------+-------------+---------+
|IP Range Name |IP Start     |IP End       |IP count |
|--------------+-------------+-------------+---------+
|range_1        |192.168.0.5  |192.168.0.10 |6        |
+--------------+-------------+-------------+---------+
|range_2        |192.168.0.20 |192.168.0.30 |11       |
+--------------+-------------+-------------+---------+

show dhcp_server option

This command is used to show dhcp_server customized option.

  • Usage

    show dhcp_server ipv4 option [<option_name>]

  • Example

    show dhcp_server ipv4 option option_1
+-------------+-------+------------+------------+
|Option Name  |Option |Value       |Type        |
|-------------+-------+------------+------------+
|option_1     |12     |host_1      |text        |
+-------------+-------+------------+------------+

show dhcp_server ipv4 option
+-------------+-------+------------+------------+
|Option Name  |Option |Value       |Type        |
|-------------+-------+------------+------------+
|option_1     |12     |host_1      |text        |
+-------------+-------+------------+------------+
|option_2     |60     |host_1      |text        |
+-------------+-------+------------+------------+

show dhcp_server lease

This command is used to show dhcp_server lease.

  • Usage

    show dhcp_server ipv4 lease [<dhcp_interface>]

  • Example

    show dhcp_server ipv4 lease Vlan1000
+-----------+------------------+------------+--------------------+--------------------+
|Interface  |MAC Address       |IP          |Lease Start         |Lease End           |
|-----------+------------------+------------+--------------------+--------------------+
|Vlan1000   |2c:2c:2c:2c:2c:2c |192.168.0.2 |2023-02-02 10:00:00 |2023-02-02 10:15:00 |
|           |2b:2b:2b:2b:2b:2b |192.168.0.3 |2023-02-02 10:20:00 |2023-02-02 10:35:00 |
+-----------+------------------+------------+--------------------+--------------------+

show dhcp_server ipv4 lease
+-----------+------------------+------------+--------------------+--------------------+
|Interface  |MAC Address       |IP          |Lease Start         |Lease End           |
+-----------+------------------+------------+--------------------+--------------------+
|Vlan1000   |2c:2c:2c:2c:2c:2c |192.168.0.2 |2023-02-02 10:00:00 |2023-02-02 10:15:00 |
|           |2b:2b:2b:2b:2b:2b |192.168.0.3 |2023-02-02 10:20:00 |2023-02-02 10:35:00 |
+-----------+------------------+------------+--------------------+--------------------+
|Vlan1001   |2e:2e:2e:2e:2e:2e |192.168.8.2 |2023-02-02 09:00:00 |2023-02-02 09:15:00 |
+-----------+------------------+------------+--------------------+--------------------+

Test

Unit Test

Config CLI

  • config dhcp_server ipv4 add [--mode ] [--infer_gw_nm] [--lease_time <lease_time>] [--gateway ] [--netmask ] <dhcp_interface>
Case DescriptionExpected res
Add with --infer_gw_nm, --mode=PORTAdd success, state is disabled
Add with --mode=DYNAMICAdd failed because mode not supported
Add interface not existAdd failed
Add without --modeAdd failed because mode is missing
Add without --infer_gw_nm, --gateway and --netmaskAdd failed because netmask and gateway is not specified
Add with invalid netmaskAdd failed because netmask invalid
Add with invalid gatewayAdd failed because gateway invalid
Add with invalid lease_timeAdd failed because lease_time invalid
  • config dhcp_server ipv4 del
Case DescriptionExpected res
Delete valid interfaceDelete success
Delete interface not existDelete failed
  • config dhcp_server ipv4 (enable | disable) <dhcp_interface>
Case DescriptionExpected res
Enable valid interfaceEnable success
Enable invalid interfaceEnable failed
Enable enabled interfaceEnable success
Disable valid interfaceDisable success
Disable invalid interfaceDisable failed
Disable disabled interfaceDisable success
  • config dhcp_server ipv4 update -mode [--infer_gw_nm] [--lease_time <lease_time>] [--gateway ] [--netmask ] <dhcp_interface>
Case DescriptionExpected res
Update with --infer_gw_nm, --mode=PORTUpdate success
Update not exist dhcp_server interfaceUpdate failed
Update invalid interfaceUpdate failed
Update with invalid netmaskUpdate failed
Update with invalid gatewayUpdate failed because gateway invalid
Update with invalid lease_timeUpdate failed because lease_time invalid
  • config dhcp_server ipv4 range add <range_name> <ip_start> [<ip_end>]
Case DescriptionExpected res
Add without ip_endAdd success
Add with ip_start and ip_endAdd success
Add with ip_start greater than ip_endAdd failed
Add existed rangeAdd failed
  • config dhcp_server ipv4 range update <range_name> <ip_start> [<ip_end>]
Case DescriptionExpected res
Update without ip_endUpdate success
Update with ip_start and ip_endUpdate success
Update with ip_start greater than ip_endUpdate failed
Update existed rangeUpdate failed
  • config dhcp_server ipv4 range del <range_name>
Case DescriptionExpected res
Delete valid rangeDelete success
Delete not exist rangeDelete failed
  • config dhcp_server ipv4 ip bind <vlan_interface> (--range <ip_range_list> | <ip_list>)
Case DescriptionExpected res
Bind valid vlan_interface, interface with valid ip_range_listBind success
Bind valid vlan_interface, interface with valid ip_listBind success
Bind no exist vlan_interfaceBind failed
Bind interface not in related vlan_interfaceBind failed
Bind ip_range_list not in vlan netBind failed
Bind ip_list not in vlan netBind failed
  • config dhcp_server ipv4 ip unbind <vlan_interface> (--range <ip_range_list> | <ip_list> | all)
Case DescriptionExpected res
Unbind valid vlan_interface, interface with valid ip_range_listUnbind success
Unbind valid vlan_interface, interface with valid ip_listUnbind success
Unbind valid vlan_interface, interface with allUnbind success, all ips/ranges are unbind
Unbind no exist vlan_interfaceUnbind failed
Unbind interface not in related vlan_interfaceUnbind failed
Unbind ip_range_list not binded in interfaceUnbind failed
Unbind ip_list not binded in interfaceUnbind failed
  • config dhcp_server ipv4 option add <option_name> <option_id> []
Case DescriptionExpected res
Add with valid name, option_id, type, valueAdd success
Add with invalid option_idAdd failed
Add with invalid typeAdd failed
Add with value inconsistent with typeAdd failed
Add with type inconsistent with option_id defined by RFCAdd failed
  • config dhcp_server ipv4 option del <option_name>
Case DescriptionExpected res
Delete valid optionDelete success
Delete not exist optionDelete failed
  • config dhcp_server ipv4 option bind <dhcp_interface> <option_list>
Case DescriptionExpected res
Bind valid dhcp_interface with valid option_listBind success
Bind no exist dhcp_interfaceBind failed
Bind no exist option_listBind failed
  • config dhcp_server ipv4 option unbind <dhcp_interface> (--all | <option_name>)
Case DescriptionExpected res
Unbind valid dhcp_interface with valid option_nameUnbind success
Unbind valid dhcp_interface with valid allUnbind success, all options unbind
Unbind valid dhcp_interface with invalid option_nameUnbind failed
Unbind no exist dhcp_interfaceUnbind failed

Show CLI

  • show dhcp_server ipv4 info [--with_customize_option] [<dhcp_interface>]
Case DescriptionExpected res
Show without dhcp_interfaceDisplay all info of dhcp_interface
Show valid dhcp_interface without --with_customize_optionDisplay dhcp info without customized option
Show valid dhcp_interface with --with_customize_optionDisplay dhcp info with customized option
Show no exist dhcp_interfaceError
  • show dhcp_server ipv4 range [<range_name>]
Case DescriptionExpected res
Show without range_nameDisplay all ranges
Show with valid range_nameDisplay range
Show no exist range_nameError
  • show dhcp_server ipv4 option [<option_name>]
Case DescriptionExpected res
Show without option_nameDisplay all options
Show with valid option_nameDisplay option
Show no exist option_nameError
  • show dhcp_server ipv4 lease [<dhcp_interface>]
Case DescriptionExpected res
Show without dhcp_interfaceDisplay all DHCP interface
Show with valid dhcp_interfaceDisplay DHCP interface
Show no exist dhcp_interfaceError

Others

  • Verify config for kea-dhcp-server and dhcrelay generated by dhcpservd are correct

Test Plan

Test plan will be published in sonic-net/sonic-mgmt