DHCP client management

ip address dhcp

This command enables the retrieving of the dynamic IP address of a configurable interface using the DHCP protocol.

The use of a negative form (no) of the command disables retrieving of the dynamic IP address using the DHCP protocol.

Syntax
[no] ip address dhcp
Parameters

The command does not contain parameters.

Default value

Disabled.

Required privilege level

10

Command mode

CONFIG-GI

CONFIG-TE

CONFIG-SUBIF

CONFIG-QINQ-IF

CONFIG-PORT-CHANNEL

CONFIG-BRIDGE

Example
esr(config-if-gi)# ip address dhcp
CODE

ip dhcp client ignore

This command specifies DHCP options that will be ignored by the client.

Syntax
[no] ip dhcp client ignore <OPTION>
Parameters

<OPTION> – takes the following values:

  • dns-nameserver – DHCP option 6, list of DNS servers;
  • domain-name – DHCP option 15, domain name;
  • netbios-nameserver – DHCP option 44, list of NetBios servers;
  • router – DHCP option 3, default gateway list;
  • classless-static-route – DHCP option 121, list of classless static routes;
  • classful-static-route – DHCP option 33, list of classless static routes;
  • tftp-server-address – DHCP option 66, TFTPserver name (not applicable for bridge interfaces);
  • vendor-specific – DHCP option 43, manufacturer specific information.
Required privilege level

10

Command mode

CONFIG-GI

CONFIG-TE

CONFIG-SUBIF

CONFIG-QINQ-IF

CONFIG-PORT-CHANNEL

CONFIG-BRIDGE

Example
esr(config-if-gi)# ip dhcp client ignore router
CODE

ip dhcp client lease-time

This command sets the requested lease time for the network address.

The use of a negative form (no) of the command sets the default value.

Syntax
ip dhcp client lease-time <TIME>
no ip dhcp client lease-time
Parameters

<TIME> – requested lease time, sets as DD:HH:MM, where:

  • DD – days, takes the value of [0..364];
  • HH – hours, takes the value of [0..23];
  • MM – minutes, takes the value of [0 ..59].
Default value

1 day

Required privilege level

10

Command mode

CONFIG-GI

CONFIG-TE

CONFIG-SUBIF

CONFIG-QINQ-IF

CONFIG-PORT-CHANNEL

CONFIG-BRIDGE

Example
esr(config-if-gi)# ip dhcp client lease-time 00:12:00
CODE

ip dhcp client reboot

This command sets the time during which the DHCP client will try to get the old IP address before starting to get a new one.

The use of a negative form (no) of the command sets the default value.

Syntax
ip dhcp client reboot <SEC>
no ip dhcp client reboot
Parameters

<SEC> – time interval in seconds, takes values of [1..600].

Default value

10

Required privilege level

10

Command mode

CONFIG-GI

CONFIG-TE

CONFIG-SUBIF

CONFIG-QINQ-IF

CONFIG-PORT-CHANNEL

CONFIG-BRIDGE

Example
esr(config-if-gi)# ip dhcp client reboot 60
CODE

ip dhcp client retry

This command sets the interval at which the DHCP client will resume attempts to obtain an IP‑address if it has been defined that the DHCP server is not responding.

The use of a negative form (no) of the command sets the default value.

Syntax
ip dhcp client retry <SEC>
no ip dhcp client retry
Parameters

<SEC> – time interval in seconds, takes values of [1..600].

Default value

300

Required privilege level

10

Command mode

CONFIG-GI

CONFIG-TE

CONFIG-SUBIF

CONFIG-QINQ-IF

CONFIG-PORT-CHANNEL

CONFIG-BRIDGE

Example
esr(config-if-gi)# ip dhcp client retry 180
CODE

ip dhcp client select-timeout

This command sets the time period during which the DHCP client will choose among the rental offers from the servers, if any. This is used in networks with multiple DHCP servers. Multiple offers may be sent to the client in response to an IP address request. It is possible that one of these sentences is preferable to the other (for example, one sentence may have an address that the client used previously).

The client waits for the specified period of time from the moment of sending the request for receiving the IP address, in case it receives several offers from various DHCP servers. After the specified time, the client accepts one of the offers.

The use of a negative form (no) of the command sets the default value.

Syntax
ip dhcp client select-timeout <SEC>
no ip dhcp client select-timeout
Parameters

<SEC> – time interval in seconds, takes values of [1..600]

Default value

0 seconds – the customer will accept the first offer received.

Required privilege level

10

Command mode

CONFIG-GI

CONFIG-TE

CONFIG-SUBIF

CONFIG-QINQ-IF

CONFIG-PORT-CHANNEL

CONFIG-BRIDGE

Example
esr(config-if-gi)# ip dhcp client select-timeout 30
CODE

ip dhcp client timeout

The command sets the interval after which the client considers DHCP server as unavailable. If there are any rented addresses in the database of client's IP addresses, the lease term of which has not expired, the client will check each of them sequentially and, if it finds the correct one, then the IP address from it will be assigned to the interface. If there are no valid leases in the database, the client will re-request the IP address after the retry interval (dhcp retry) expires. The use of a negative form (no) of the command sets the default value.

Syntax
ip dhcp client timeout <SEC>
no ip dhcp client timeout
Parameters

<SEC> – time interval in seconds, takes values of [1..600].

Default value

60 seconds

Required privilege level

10

Command mode

CONFIG-GI

CONFIG-TE

CONFIG-SUBIF

CONFIG-QINQ-IF

CONFIG-PORT-CHANNEL

CONFIG-BRIDGE

Example
esr(config-if-gi)# ip dhcp client timeout 300
CODE

ip dhcp client vendor-class-id

This command sets the value of DHCP Option 60 to get additional settings for DHCP Option 43.

The use of a negative form (no) of the command disables request of this feature.

Syntax
ip dhcp client vendor-class-id <NAME>
no ip dhcp client vendor-class-id
Parameters

<NAME> – carrier class identifier, set by the string of up to 31 characters.

Required privilege level

10

Command mode

CONFIG-GI

CONFIG-TE

CONFIG-SUBIF

CONFIG-QINQ-IF

CONFIG-PORT-CHANNEL

CONFIG-BRIDGE

Example
esr(config-if-gi)# ip dhcp client vendor-class-id ELTEX
CODE

ip dhcp server address

This command sets the IP address of the DHCP server from which the IP address will be requested.

The use of a negative form (no) of the command removes set DHCP server IP address.

Syntax
ip dhcp server address <ADDR>
no ip dhcp server address
Parameters

<ADDR> – IP address, defined as AAA.BBB.CCC.DDD where each part takes values of [0..255].

Required privilege level

10

Command mode

CONFIG-GI

CONFIG-TE

CONFIG-SUBIF

CONFIG-QINQ-IF

CONFIG-PORT-CHANNEL

CONFIG-BRIDGE

Example
esr(config-if-gi)# ip dhcp server address 10.10.10.1
CODE

renew dhcp

This command sends a request to update the IP address via DHCP.

Syntax
renew dhcp <IF>
Parameters

<IF> – name of an interface or a group of interfaces is specified in the form described in Section Types and naming order of router interfaces;

Required privilege level

10

Command mode

ROOT

Example
esr# renew dhcp gigabitethernet 1/0/1
CODE

IPv6 DHCP client management

ipv6 address dhcp

This command enables the retrieving of the dynamic IPv6 address of a configurable interface using the IPv6 DHCP protocol.

The use of a negative form (no) of the command disables retrieving of the dynamic IPv6 address using the IPv6 DHCP protocol.

Syntax
[no] ipv6 address dhcp
Parameters

The command does not contain parameters.

Default value

Disabled.

Required privilege level

10

Command mode

CONFIG-GI

CONFIG-TE

CONFIG-SUBIF

CONFIG-QINQ-IF

CONFIG-PORT-CHANNEL

CONFIG-BRIDGE

Example
esr(config-if-gi)# ipv6 address dhcp
CODE

ipv6 dhcp client ignore

This command specifies DHCP options that will be ignored by the client.

Syntax
ipv6 dhcp client ignore <OPTION>
no ipv6 dhcp client ignore
Parameters

<OPTION> – takes the following values:

  • dns-nameserver – DHCP option 23, list of DNS servers;
  • domain-name – DHCP option 24, domain name;
  • vendor-specific – DHCP option 17, manufacturer specific information.
Required privilege level

10

Command mode

CONFIG-GI

CONFIG-TE

CONFIG-SUBIF

CONFIG-QINQ-IF

CONFIG-PORT-CHANNEL

CONFIG-BRIDGE

Example
esr(config-if-gi)# ipv6 dhcp client ignore dns-nameserver
CODE

ipv6 dhcp client lease-time

This command sets the requested lease time for the network address.

The use of a negative form (no) of the command sets the default value.

Syntax
ipv6 dhcp client lease-time <TIME>
no ipv6 dhcp client lease-time
Parameters

<TIME> – requested lease time, sets as DD:HH:MM, where:

  • DD – days, takes the value of [0..364];
  • HH – hours, takes the value of [0..23];
  • MM – minutes, takes the value of [0 ..59].
Default value

1 day

Required privilege level

10

Command mode

CONFIG-GI

CONFIG-TE

CONFIG-SUBIF

CONFIG-QINQ-IF

CONFIG-PORT-CHANNEL

CONFIG-BRIDGE

Example
esr(config-if-gi)# ipv6 dhcp client lease-time 00:12:00
CODE

ipv6 dhcp client reboot

This command sets the time during which the IPv6 DHCP client will try to get the old IPv6 address before starting to get a new one.

The use of a negative form (no) of the command sets the default value.

Syntax
ipv6 dhcp client reboot <SEC>
no ipv6 dhcp client reboot
Parameters

<SEC> – time interval in seconds, takes values of [1..600].

Default value

10

Required privilege level

10

Command mode

CONFIG-GI

CONFIG-TE

CONFIG-SUBIF

CONFIG-QINQ-IF

CONFIG-PORT-CHANNEL

CONFIG-BRIDGE

Example
esr(config-if-gi)# ipv6 dhcp client reboot 60
CODE

ipv6 dhcp client retry

This command sets the interval at which the IPv6 DHCP client will resume attempts to obtain an IPv6‑address if it has been defined that the IPv6 DHCP server is not responding.

The use of a negative form (no) of the command sets the default value.

Syntax
ipv6 dhcp client retry <SEC>
no ipv6 dhcp client retry
Parameters

<SEC> – time interval in seconds, takes values of [1..600].

Default value

300

Required privilege level

10

Command mode

CONFIG-GI

CONFIG-TE

CONFIG-SUBIF

CONFIG-QINQ-IF

CONFIG-PORT-CHANNEL

CONFIG-BRIDGE

Example
esr(config-if-gi)# ipv6 dhcp client retry 180
CODE

ipv6 dhcp client select-timeout

This command sets the time period during which the IPv6 DHCP client will choose among the rental offers from the servers, if any. This is used in networks with multiple IPv6 DHCP servers — in this case, multiple offers may be sent to the client in response to a request for an IPv6 address. It is possible that one of these sentences is preferable to the other (for example, one sentence may have an address that the client used previously).

The client waits for the specified period of time from the moment of sending the request for receiving the IP address, in case it receives several offers from various DHCPv6 servers. After the specified time, the client accepts one of the offers.

The use of a negative form (no) of the command sets the default value.

Syntax
ipv6 dhcp client select-timeout <SEC>
no ipv6 dhcp client select-timeout
Parameters

<SEC> – time interval in seconds, takes values of [1..600].

Default value

0 – the customer will accept the first offer received.

Required privilege level

10

Command mode

CONFIG-GI

CONFIG-TE

CONFIG-SUBIF

CONFIG-QINQ-IF

CONFIG-PORT-CHANNEL

CONFIG-BRIDGE

Example
esr(config-if-gi)# ipv6 dhcp client select-timeout 30
CODE

ipv6 dhcp client timeout

The command sets the interval after which the client considers IPv6 DHCP server as unavailable. If there are any rented addresses in the database of client's IPv6 addresses, the lease term of which has not expired, the client will check each of them sequentially and, if it finds the correct one, then the IPv6 address from it will be assigned to the interface. If there are no valid leases in the database, the client will re-request the IPv6 address after the retry interval (dhcp retry) expires.

The use of a negative form (no) of the command sets the default value.

Syntax
ipv6 dhcp client timeout <SEC>
no ipv6 dhcp client timeout
                                        

<SEC> – time interval in seconds, takes values of [1..600].

Default value

60 seconds

Required privilege level

10

Command mode

CONFIG-GI

CONFIG-TE

CONFIG-SUBIF

CONFIG-QINQ-IF

CONFIG-PORT-CHANNEL

CONFIG-BRIDGE

Example
esr(config-if-gi)# ipv6 dhcp client timeout 300
CODE

ipv6 dhcp client vendor-class-id

This command sets the value of DHCP Option 60 to get additional settings for DHCP Option 43.

The use of a negative form (no) of the command disables request of this feature.

Syntax
ipv6 dhcp client vendor-class-id <NAME>
no ipv6 dhcp client vendor-class-id
Parameters

<NAME> – carrier class identifier, set by the string of up to 31 characters.

Default value

None

Required privilege level

10

Command mode

CONFIG-GI

CONFIG-TE

CONFIG-SUBIF

CONFIG-QINQ-IF

CONFIG-PORT-CHANNEL

CONFIG-BRIDGE

Example
esr(config-if-gi)# ipv6 dhcp client vendor-class-id ELTEX
CODE

ipv6 dhcp server address

This command sets the IPv6 address of the DHCP server from which the IPv6 address will be requested.

The use of a negative form (no) of the command removes set DHCP server IPv6 address.

Syntax
ipv6 dhcp server address <IPV6-ADDR>
no ipv6 dhcp server address
Parameters

<IPV6-ADDR> – IPv6 address, defined as X:X:X:X::X where each part takes values in hexadecimal format [0..FFFF].

Required privilege level

10

Command mode

CONFIG-GI

CONFIG-TE

CONFIG-SUBIF

CONFIG-QINQ-IF

CONFIG-PORT-CHANNEL

CONFIG-BRIDGE

Example
esr(config-if-gi)# ipv6 dhcp server address fc00::1
CODE

renew ipv6 dhcp

This command sends a request to update the IPv6 address via DHCP.

Syntax
renew ipv6 dhcp <IF>
Parameters

<IF> – name of an interface or a group of interfaces is specified in the form described in Section Types and naming order of router interfaces;

Required privilege level

10

Command mode

ROOT

Example
esr# renew ipv6 dhcp gigabitethernet 1/0/1
CODE

DHCP Relay agent management

ip dhcp information option

This command enables the processing of the option 82 by DHCP Relay agent.

The use of a negative form (no) of the command disables the processing of the option 82 by DHCP Relay agent.

Syntax
[no] ip dhcp information option
Parameters

The command does not contain parameters.

Default value

Disabled.

Required privilege level

10

Command mode

CONFIG

Example
esr(config)# ip dhcp information option
CODE

ip dhcp information option action

This command allows you to change the decision that will be made by the router upon receipt of a packet with option 82 installed.

The use of a negative form (no) of the command sets the default value.

Syntax
ip dhcp information option action { replace | keep | drop }
no ip dhcp information option action
Parameters
  • replace – replace set option 82 by new;
  • keep – keep set option 82 without changes;
  • drop – remove the package if the installed option 82 is found in it.
Default value

keep

Required privilege level

10

Command mode

CONFIG-GI

CONFIG-TE

CONFIG-SUBIF

CONFIG-QINQ-IF

CONFIG-PORT-CHANNEL

CONFIG-BRIDGE

Example
esr(config-if-gi)# ip dhcp information option action drop
CODE

ip dhcp information option format-type access-node-id

This command specifies the Access-node-ID in the Circuit ID field of option 82 when using the tr101 format.

The use of a negative form (no) of the command sets the default value.

Syntax
[no] ip dhcp information option format-type access-node-id <NODE-ID>
Parameters

<NODE-ID> – Access-node-ID value, sets by the string up to 31 characters.

Default value

Device hostname.

Required privilege level

10

Command mode

CONFIG

Example
esr(config)# ip dhcp information option format-type access-node-id R1
CODE

ip dhcp information option format-type circuit-id

This command sets the value of the Circuit ID field of option 82 when using any format.

The use of a negative form (no) of the command sets the default value.

Syntax
[no] ip dhcp information option format-type circuit-id <CIRCUIT-ID>
Parameters

<ID> – network interface identifier, set by the string of up to 63 characters.

Default value

Defined by the format used.

Required privilege level

10

Command mode

CONFIG-GI

CONFIG-TE

CONFIG-SUBIF

CONFIG-QINQ-IF

CONFIG-PORT-CHANNEL

CONFIG-BRIDGE

Example
esr(config-if-gi)# ip dhcp information option format-type circuit-id gi1_0_1
CODE

ip dhcp information option format-type option

This command specifies the port identifier format in the Circuit ID field of option 82 when using the tr101 format.

The use of a negative form (no) of the command sets the default value.

Syntax
[no] ip dhcp information option format-type option <FORMAT> [ delimeter <DELIMITER> ]
Parameters

<FORMAT> – port identifier format, takes one of following values:

  • sp – string contains slot and port number;
  • sv – string contains slot and VLAN number;
  • pv – string contains port and VLAN number;
  • spv – string contains slot, port and VLAN number;
  • bin – binary format: VLAN (4 bytes), slot (1 byte), port (4 bytes).

<DELIMITER> – separator between parameters in a string, can be one of the following values [ . , ; # / space ].

Default value

Format – spv

Separator ':' for formats: sp, sv, pv

Separator '/' и ':' for format spv

Required privilege level

10

Command mode

CONFIG

Example
esr(config)# ip dhcp information option format-type option spv delimeter #
CODE

ip dhcp information option format-type remote-id

This command sets the value of the Remote ID field of option 82 when using any format.

The use of a negative form (no) of the command sets the default value.

Syntax
[no] ip dhcp information option format-type remote-id <REMOTE-ID>
Parameters

<ID> – network interface identifier, set by the string of up to 63 characters.

Default value

Defined by the format used.

Required privilege level

10

Command mode

CONFIG-GI

CONFIG-TE

CONFIG-SUBIF

CONFIG-QINQ-IF

CONFIG-PORT-CHANNEL

CONFIG-BRIDGE

Example
esr(config-if-gi)# ip dhcp information option format-type remote-id R1
CODE

ip dhcp information option suboption-type

This command selects option 82 format.

The use of a negative form (no) of the command sets the default value.

Syntax
[no] ip dhcp information option suboption-type { tr101 | custom }
Parameters

tr101 – recommended TR-101 format of option 82 according to the syntax adopted in TR-101 recommendations (see table 10);

custom – format option 82 in accordance with the format shown in table 11.

Table 10 – Option 82 field format as per TR-101 recommendations

Field

Transmitted information

Circuit ID

Access-Node-Id, default is device hostname (format can be changed using the «ip dhcp information option format-type access-node-id» command. It is described in Section ip dhcp information option format-type access-node-id)

String in the form of eth <stacked/slotid/interfaceid>:<vlan> (format can be changed using the «ip dhcp information option format-type option» command. It is described in Section ip dhcp information option format-type option)

The last byte is the port number to which the device is connected, sending a dhcp request.

Remote agent ID

Enterprise number – 0089c1

Device Mac Address

Table 11 – Option 82 of custom mode fields format

Field

Transmitted information

Circuit ID

Length (1 byte)

Circuit ID type

Length (1 byte)

VLAN (2 bytes)

Module number (1 byte)

Port number (4 byte)

Remote agent ID

Length (1 byte)

Remote ID Type (1 byte)

Length (1 byte)

Switch MAC address

Default value

tr101

Required privilege level

10

Command mode

CONFIG

Example
esr(config)# ip dhcp information option suboption-type custom
CODE

ip dhcp-relay

This command is used to enable DHCP-relay agent.

The use of a negative form (no) of the command disables DHCP-relay agent.

Syntax
[no] ip dhcp-relay
Parameters

The command does not contain parameters.

Default value

Disabled.

Required privilege level

10

Command mode

CONFIG

Example
esr(config)# ip dhcp-relay
CODE

ip helper-address

This command specifies the IP address of the DHCP server to which DHCP Discover packets intercepted by the DHCP Relay agent will be sent.

The use of a negative form (no) of the command removes the IP address from the list of DHCP servers for the DHCP Relay agent.

Syntax
[no] ip helper-address <IP>
Parameters

<IP> – DHCP server IP address, defined as AAA.BBB.CCC.DDD where each part takes values of [0..255]. You can specify up to 4 IP addresses separated by commas.

Required privilege level

10

Command mode

CONFIG-GI

CONFIG-TE

CONFIG-SUBIF

CONFIG-QINQ-IF

CONFIG-PORT-CHANNEL

CONFIG-BRIDGE

Example
esr(config-if-gi)# ip helper-address 10.10.10.1
CODE

ip helper-address vrrp-group

This command restricts sending of DHCP Discover packets captured by the DHCP Relay agent if the VRRP group is in the DOWN state.

The use of a negative form (no) of the command allows sending of DHCP Discover packets captured by the DHCP Relay agent if the VRRP group is in the DOWN state.

Syntax
ip helper-address vrrp-group <GRID>
no ip helper-address vrrp-group
Parameters

<GRID> – VRRP router group identifier, takes values in the range of [1..32].

Required privilege level

10

Command mode

CONFIG-GI

CONFIG-TE

CONFIG-SUBIF

CONFIG-QINQ-IF

CONFIG-PORT-CHANNEL

CONFIG-BRIDGE

Example
esr(config-if-gi)# ip helper-address vrrp-group 7
CODE

IPv6 DHCP Relay agent management

ipv6 dhcp-relay

The command enables IPv6 DHCP agent.

The use of a negative form (no) of the command disables IPv6 DHCP agent.

Syntax
[no] ipv6 dhcp-relay
Parameters

The command does not contain parameters.

Default value

Disabled.

Required privilege level

10

Command mode

CONFIG

Example
esr(config)# ipv6 dhcp-relay
CODE

ipv6 dhcp-relay interface

This command specifies the outgoing interface and IPv6 address of the DHCP server to which DHCP Solicit packets intercepted by the IPv6 DHCP Relay agent will be sent.

The use of a negative form (no) of the command removes the outgoing interface from the list of interfaces for the IPv6 DHCP Relay agent.

Syntax
ipv6 dhcp-relay interface <IF> [ <IPV6-ADDR> ]
no ipv6 dhcp-relay interface <IF>
Parameters

<IF> – name of an interface or a group of interfaces is specified in the form described in Section Types and naming order of router interfaces;

<IPV6-ADDR> – DHCP server IPv6 address, defined as X:X:X:X::X where each part takes values in hexadecimal format [0..FFFF]. If the address is not specified, packets are sending to ff02::1:2. All IPv6 DHCP servers and agents in the local network segment.

Required privilege level

10

Command mode

CONFIG-GI

CONFIG-TE

CONFIG-SUBIF

CONFIG-QINQ-IF

CONFIG-PORT-CHANNEL

CONFIG-BRIDGE

Example
esr(config-if-gi)# ipv6 dhcp-relay interface gigabitethernet 1/0/2 fc00::1
CODE

DHCP server monitoring and configuration

clear ip dhcp binding

This command clears the IP addresses issued by the DHCP server.

Syntax
clear ip dhcp binding [ <ADDR> ] [vrf <VRF>]
Parameters

<ADDR> – IP address, optional parameter, defined as AAA.BBB.CCC.DDD where each part takes values of [0..255]. If the <ADDR> parameter is specified in the command, then information associated only with the specified address will be displayed.

<VRF> – name of the VRF instance for which the information will be displayed. Set by the string of up to 31 characters.

Required privilege level

10

Command mode

ROOT

Example
esr# clear ip dhcp binding
CODE

address

This command adds an IP address for a specific physical address to the address pool of a configurable DHCP server.

The use of a negative form (no) of the command removes a specified IP address.

Syntax
address <ADDR> { mac-address <MAC> | client-identifier <CLIENT-ID> }
no address <ADDR>
Parameters

<ADDR> – client IP address, defined as AAA.BBB.CCC.DDD where each part takes values of [0..255]; If the command is used for removal, when specifying the 'all' value all IP addresses will be removed.

<MAC> – MAC address of the client, which will be given the IP address, defined as XX: XX: XX: XX: XX: XX where each part takes the values of [00..FF].

<CLIENT-ID> – client identifier according to DHCP option 61.

Required privilege level

10

Command mode

CONFIG-DHCP-SERVER

Example
esr(config-dhcp-server)# address 192.168.3.21 mac-address A8:F9:4B:AA:00:40
CODE

address-range

This command adds a range of IP addresses to the address pool configured by the DHCP server.

The use of a negative form (no) of the command removes a specified range of IP addresses.

Syntax
address-range <FROM-ADDR>-<TO-ADDR>
no address-range { <FROM-ADDR>-<TO-ADDR> | all }
Parameters

<FROM-ADDR> – range starting IP address, defined as AAA.BBB.CCC.DDD where each part takes values of [0..255];

<TO-ADDR> – range ending IP address, defined as AAA.BBB.CCC.DDD where each part takes values of [0..255].

You can specify up to 32 IP addresses separated by commas.

all – remove all configured IP address ranges.

Required privilege level

10

Command mode

CONFIG-DHCP-SERVER

Example
esr(config-dhcp-server)# address-range 192.168.3.1-192.168.3.20,192.168.3.24
CODE

default-lease-time

This command sets the lease time for which the client will receive an IP address if the client has not requested a specific lease time. The use of a negative form (no) of the command sets the default value.

Syntax
default-lease-time <TIME>
no default-lease-time
Parameters

<TIME> – IP address lease time, in format DD:HH:MM, where:

  • DD – amount of days, takes values of [0..364].
  • HH – amount of hours, takes values of [0..23].
  • MM – amount of minutes, takes the value of [0 ..59].
Default value

12 hours

Required privilege level

10

Command mode

CONFIG-DHCP-SERVER

Example
esr(config-dhcp-server)# default-lease-time 00:04:00
CODE

default-router

This command specifies a list of default gateway IP addresses that the DHCP server will communicate to clients using DHCP option 3.

The use of a negative form (no) of the command removes a specified addresses from the list of gateways.

Syntax
default-router <ADDR>
no default-router { <ADDR> | all }
Parameters

<ADDR> – default gateway IP address, defined as AAA.BBB.CCC.DDD where each part takes values of [0..255]; You can specify up to 8 IP addresses separated by commas. If the command is used for removal, when specifying the 'all' value all default gateways will be removed.

Required privilege level

10

Command mode

CONFIG-DHCP-SERVER

Example
esr(config-dhcp-server)# default-router 192.168.3.1,192.168.3.2
CODE

dns-server

This command specifies a list of IP addresses of DNS servers. The list is transferred to clients as part of the DHCP options.

The use of a negative form (no) of the command removes DNS server from the list.

Syntax
dns-server <ADDR>
no dns-server { <ADDR> | all }
Parameters

<ADDR> – DNS server IP address, defined as AAA.BBB.CCC.DDD where each part takes values of [0..255]. You can specify up to 8 IP addresses separated by commas. If the command is used for removal, when specifying the 'all' value all DNS servers will be removed.

Required privilege level

10

Command mode

CONFIG-DHCP-SERVER

Example
esr(config-dhcp-server)# dns-server 8.8.8.8,8.8.4.4
CODE

domain-name

This command specifies the DNS name of the network domain. The domain name is transferred to clients as part of the DHCP option 15.

The use of a negative form (no) of the command removes a specified domain name.

Syntax
domain-name <NAME>
no domain-name
Parameters

<NAME> – router domain name, set by the string from 1 to 255 characters.

Required privilege level

10

Command mode

CONFIG-DHCP-SERVER

Example
esr(config-dhcp-server)# domain-name eltex.loc
CODE

excluded-address-range

This command excludes a range of IP addresses from the address pool configured by the DHCP server.

The use of a negative form (no) of the command removes a specified range of IP addresses.

Syntax
[no] excluded-address-range <FROM-ADDR>-<TO-ADDR>
Parameters

<FROM-ADDR> – range starting IP address, defined as AAA.BBB.CCC.DDD where each part takes values of [0..255];

<TO-ADDR> – range ending IP address, defined as AAA.BBB.CCC.DDD where each part takes values of [0..255].

You can specify up to 32 IP addresses separated by commas.

Required privilege level

10

Command mode

CONFIG-DHCP-SERVER

Example
esr(config-dhcp-server)# excluded-address-range 192.168.3.1-192.168.3.20,192.168.3.24
CODE

ip dhcp-server

This command enables DHCP server.

The use of a negative form (no) of the command disables DHCP server.

Syntax
[no] ip dhcp-server [vrf <VRF>]
Parameters

<VRF> – VRF instance name, set by the string of up to 31 characters, within which the NTP server will operate. Set by the string of up to 31 characters.

Default value

Disabled.

Required privilege level

10

Command mode

CONFIG

Example
esr(config)# ip dhcp-server
CODE

ip dhcp-server dscp

The command sets the DSCP code value for the use in IP headers of DHCP server outgoing packets.

The use of a negative form (no) of the command sets the default DSCP value.

Syntax
ip dhcp-server dscp <DSCP>
no ip dhcp-server dscp
Parameters

<DSCP> – DSCP code value, takes values in the range of [0..63].

Default value

61

Required privilege level

10

Command mode

CONFIG

Example
esr(config)# ip dhcp-server dscp 40
CODE

ip dhcp-server pool

This command creates a pool of IP addresses of the DHCP server and switch to its configuration mode.

The use of a negative form (no) of the command removes a specified pool of IP addresses.

Syntax
ip dhcp-server pool <NAME> [vrf <VRF>]
no ip dhcp-server pool { <NAME> | all }
Parameters

<NAME> – NAT addresses pool name, set by the string of up to 31 characters. The use of a negative form (no) of the command with ‘all’ parameter removes all IP address pools. If the command is used for removal, when specifying the 'all' value all IP addresses will be removed.

<VRF> – VRF instance name, within which the NTP server will operate. Set by the string of up to 31 characters.

Required privilege level

10

Command mode

CONFIG

Example
esr(config)# ip dhcp-server pool lan
CODE

ip dhcp-server vendor-class-id

This command creates a provider class identifier (DHCP Option 60) and switch to its configuration mode.

The use of a negative form (no) of the command removes a specified supplier class identifier.

Syntax
[no] ip dhcp-server vendor-class-id <NAME>
Parameters

<NAME> – carrier class identifier, set by the string of up to 31 characters. The use of a negative form (no) of the command with 'all' parameter removes all manufacturer class identifiers.

Required privilege level

10

Command mode

CONFIG

Example
esr(config)# ip dhcp-server vendor-class-id ELTEX
CODE

max-lease-time

This command sets the maximum lease time for IP addresses. If the DHCP client requests a lease time that exceeds the maximum value, the time specified by this command will be set. The use of a negative form (no) of the command sets the default value.

Syntax
max-lease-time <TIME>
no max-lease-time
Parameters

<TIME> – maximal IP address lease time, sets in format DD:HH:MM, where:

  • DD – amount of days, takes values of [0..364].
  • HH – amount of hours, takes values of [0..23].
  • MM – amount of minutes, takes the value of [0 ..59].
Default value

1 day

Required privilege level

10

Command mode

CONFIG-DHCP-SERVER

Example
esr(config-dhcp-server)# max-lease-time 00:16:00
CODE

netbios-name-server

This command configures the 44 DHCP option (sets the IP address of the NetBIOS server).

The use of a negative form (no) of the command disables the transfer of the IP address of the NetBIOS server (option 44).

Syntax
[no] netbios-name-server <ADDR>
Parameters

<ADDR> – NetBIOS server IP address, defined as AAA.BBB.CCC.DDD where each part takes values of [0..255]. You can set up to 4 IP addresses. The use of a negative form (no) of the command with ‘all’ parameter removes all IP addresses.

Required privilege level

10

Command mode

CONFIG-DHCP-SERVER

Example
esr(config-dhcp-server)# netbios-name-server 192.168.45.15
CODE

network

This command sets the IP address and mask for the subnet from which the pool of IP addresses will be allocated.

The use of a negative form (no) of the command removes subnet settings in pool.

Syntax
network <ADDR/LEN>
no network
Parameters

<ADDR/LEN> – IP subnet, defined as AAA.BBB.CCC.DDD/EE where each part AAA-DDD takes values of [0..255] and EE takes values of [1..32].

Required privilege level

10

Command mode

CONFIG-DHCP-SERVER

Example
esr(config-dhcp-server)# network 192.168.3.0/24
CODE

option

This command specifies DHCP options.

The use of a negative form (no) of the command removes set option.

Syntax
option <CODE> { ip-address <ADDR> | ascii-text <STRING> | hex-bytes <HEX> }
no option { <CODE> | all }
Parameters

<CODE> –  DHCP option code, set in the form of a number [0..255].

<HEX> – vendor-specific information, specified in hexadecimal format up to 255 bytes.

<ADDR> – IP address, defined as AAA.BBB.CCC.DDD where each part takes values of [0..255]. You can specify up to 15 IP addresses separated by commas.

<URL> – reference address, set by the string from 1 to 255 characters.

all – removes all options.

Default value

None

Required privilege level

10

Command mode

CONFIG-DHCP-SERVER

Example
esr(config-dhcp-server)# option 43 ip-address 10.10.1.1
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show ip dhcp binding

This command displays the IP addresses issued by the DHCP server.

Syntax
show ip dhcp binding [ <ADDR> ] [vrf <VRF>]
Parameters

<ADDR> – IP address, optional parameter, defined as AAA.BBB.CCC.DDD where each part takes values of [0..255]. If the <ADDR> parameter is specified in the command, then information associated only with the specified address will be displayed.

<VRF> – name of the VRF instance for which the information will be displayed. Set by the string of up to 31 characters.

Required privilege level

1

Command mode

ROOT

Example
esr# show ip dhcp binding
Allocated          MAC address          Binding    Lease expires at
address                                 type
----------------   ------------------   --------   -----------------------------
192.168.1.3        50:46:5d:a5:3f:91    dynamic    Thursday 2014/01/01 12:42:12
CODE

show ip dhcp server dscp

This command displays the DSCP value for DHCP messages.

Syntax
show ip dhcp server dscp
Parameters

The command does not contain parameters.

Required privilege level

1

Command mode

ROOT

Example
esr # show ip dhcp server dscp
DSCP:    32
CODE

show ip dhcp server pool

This command displays configured IP address pools. When specifying a name, only information for the specified pool is displayed.

Syntax
show ip dhcp server pool [ <POOL_NAME> ]
Parameters

<POOL_NAME> – pool name, optional parameter.

Required privilege level

1

Command mode

ROOT

Example
esr# show ip dhcp server pool lan-pool
name:               lan-pool
network:            192.168.1.0/24
address-ranges:     192.168.1.2-192.168.1.254
default-router:     192.168.1.1
max lease time:     1:0:0 (day:hour:min)
default lease time: 0:12:0 (day:hour:min)
CODE

show ip dhcp server vendor-specific

This command displays configured DHCP options 43 and 60.

Syntax
show ip dhcp server vendor-specific
Parameters

The command does not contain parameters.

Required privilege level

1

Command mode

ROOT

Example
esr# show ip dhcp server vendor-specific
Vendor ID          Vendor options
----------------   --------------------------------
 ELTEX             0x0b0931302e312e39302e32
CODE

tftp-server

This command sets TFTP server IP address. The address is transferred to clients as part of DHCP option 150.

The use of a negative form (no) of the command removes set TFTP server IP address.

Syntax
tftp-server <ADDR>
no tftp-server
Parameters

<ADDR> – TFTP server IP address, defined as AAA.BBB.CCC.DDD where each part takes values of [0..255].

Required privilege level

10

Command mode

config-dhcp-server

Example
esr(config-ipv6-dhcp-server)# tftp-server 192.168.0.1
CODE

vendor-specific-options

This command specifies vendor-specific information (DHCP Option 43).

The use of a negative form (no) of the command removes a specific carrier information.

Syntax
vendor-specific-options <HEX>
no vendor-specific-options
Parameters

<HEX> – vendor-specific information, specified in hexadecimal format up to 128 symbols.

Required privilege level

10

Command mode

CONFIG-DHCP-VENDOR-ID

Example
esr(config-dhcp-vendor-id)# vendor-specific-options 0b0931302e312e39302e320
CODE

IPv6 DHCP server monitoring and configuration

address

This command adds an IPv6 address for a specific physical address to the address pool of a configurable DHCP server.

The use of a negative form (no) of the command removes a specified IPv6 address.

Syntax
address <IPV6-ADDR> mac-address <MAC>
no address <IPV6-ADDR>
Parameters

<IPV6-ADDR> – client IPv6 address, defined as X:X:X:X::X where each part takes values in hexadecimal format [0..FFFF]. If the command is used for removal, when specifying the 'all' value all IPv6 addresses will be removed.

<MAC> – MAC address of the client, which will be given the IP address, defined as XX: XX: XX: XX: XX: XX where each part takes the values of [00..FF].

Required privilege level

10

Command mode

CONFIG-IPV6-DHCP-SERVER

Example
esr(config-ipv6-dhcp-server)# address fc00::2 mac-address A8:F9:4B:AA:00:40
CODE

address-range

This command adds a range of IPv6 addresses to the address pool configured by the DHCP server.

The use of a negative form (no) of the command removes a specified range of IPv6 addresses.

Syntax
[no] address-range <FROM-ADDR>-<TO-ADDR>
no address-range all
Parameters

<IPV6-ADDR> – server IPv6 address, defined as X:X:X:X::X where each part takes values in hexadecimal format [0..FFFF];

<IPV6-ADDR> – server IPv6 address, defined as X:X:X:X::X where each part takes values in hexadecimal format [0..FFFF];

You can specify up to 32 IP addresses separated by commas.

all – remove all configured IPv6 address ranges.

Required privilege level

10

Command mode

CONFIG-IPV6-DHCP-SERVER

Example
esr(config-ipv6-dhcp-server)# address-range fc00::1-fc00:12,fc00::15-fc00::25
CODE

default-lease-time

This command sets the lease time for which the client will receive an IPv6 address if the client has not requested a specific lease time.

The use of a negative form (no) of the command sets the default value.

Syntax
default-lease-time <TIME>
no default-lease-time
Parameters

<TIME> – IP address lease time, in format DD:HH:MM, where:

  • DD – amount of days, takes values of [0..364].
  • HH – amount of hours, takes values of [0..23].
  • MM – amount of minutes, takes the value of [0 ..59].
Default value

12 hours

Required privilege level

1

Command mode

CONFIG-IPV6-DHCP-SERVER

Example
esr(config-ipv6-dhcp-server)# default-lease-time 00:04:00
CODE

dns-server

This command specifies a list of IPv6 addresses of DNS servers. The list is transferred to clients as part of the DHCP options.

The use of a negative form (no) of the command removes DNS server from the list.

Syntax
dns-server <IPV6-ADDR>
no dns-server { <IPV6-ADDR> | all }
Parameters

<IPV6-ADDR> – DNS server IPv6 address, defined as X:X:X:X::X where each part takes values in hexadecimal format [0..FFFF]. You can specify up to 8 IP addresses separated by commas. If the command is used for removal, when specifying the 'all' value all DNS servers will be removed.

Required privilege level

10

Command mode

CONFIG-IPV6-DHCP-SERVER

Example
esr(config-ipv6-dhcp-server)# dns-server 8.8.8.8,8.8.4.4
CODE

domain-name

This command specifies the name of the network domain. The domain name is transferred to clients as part of the DHCP options.

The use of a negative form (no) of the command removes a specified domain name.

Syntax
domain-name <NAME>
no domain-name
Parameters

<NAME> – router domain name, set by the string from 1 to 255 characters.

Required privilege level

10

Command mode

CONFIG-IPV6-DHCP-SERVER

Example
esr(config-ipv6-dhcp-server)# domain-name eltex.loc
CODE

excluded-address-range

This command excludes a range of IPv6 addresses from the address pool configured by the DHCP server.

The use of a negative form (no) of the command removes a specified range of IPv6 addresses.

Syntax
[no] excluded-address-range <FROM-ADDR>-<TO-ADDR>
Parameters

<IPV6-ADDR> – server IPv6 address, defined as X:X:X:X::X where each part takes values in hexadecimal format [0..FFFF];

<IPV6-ADDR> – server IPv6 address, defined as X:X:X:X::X where each part takes values in hexadecimal format [0..FFFF];

You can specify up to 32 IP addresses separated by commas.

Required privilege level

10

Command mode

CONFIG-IPV6-DHCP-SERVER

Example
esr(config-ipv6-dhcp-server)# excluded-address-range 10::1-10::9
CODE

ipv6 dhcp-server

The command enables IPv6 DHCP server.

The use of a negative form (no) of the command disables IPv6 DHCP server.

Syntax
[no] ipv6 dhcp-server [ vrf <VRF> ]
Parameters

<VRF> – VRF instance name, set by the string of up to 31 characters, within which the NTP server will operate.

Default value

Disabled.

Required privilege level

10

Command mode

CONFIG

Example
esr(config)# ipv6 dhcp-server
CODE

ipv6 dhcp-server pool

This command creates a pool of IPv6 addresses of the DHCP server and switch to its configuration mode.

The use of a negative form (no) of the command removes a specified IPv6 address pool.

Syntax
[no] ipv6 dhcp-server pool <NAME> [vrf <VRF>]
Parameters

<NAME> – IPv6 server profile name, set by the string of up to 31 characters. The use of a negative form (no) of the command with ‘all’ parameter removes all IPv6 address pools.

<VRF> – VRF instance name, set by the string of up to 31 characters, within which the NTP server will operate.

Required privilege level

10

Command mode

CONFIG

Example
esr(config)# ipv6 dhcp-server pool lan
CODE

ipv6 dhcp-server vendor-class-id

This command creates a provider class identifier (DHCP Option 60) and switch to its configuration mode.

The use of a negative form (no) of the command removes a specified supplier class identifier.

Syntax
[no] ipv6 dhcp-server vendor-class-id <NAME>
Parameters

<NAME> – carrier class identifier, set by the string of up to 31 characters. The use of a negative form (no) of the command with 'all' parameter removes all manufacturer class identifiers.

Required privilege level

10

Command mode

CONFIG

Example
esr(config)# ipv6 dhcp-server vendor-class-id ELTEX
CODE

max-lease-time

This command sets the maximum lease time for IPv6 addresses. If the IPv6 DHCP client requests a lease time that exceeds the maximum value, the time specified by this command will be set. The use of a negative form (no) of the command sets the default value.

Syntax
max-lease-time <TIME>
no max-lease-time
Parameters

<TIME> – maximal IP address lease time, sets in format DD:HH:MM, where:

  • DD – amount of days, takes values of [0..364].
  • HH – amount of hours, takes values of [0..23].
  • MM – amount of minutes, takes the value of [0 ..59].
Default value

1 day

Required privilege level

10

Command mode

CONFIG-IPV6-DHCP-SERVER

Example
esr(config-ipv6-dhcp-server)# max-lease-time 00:16:00
CODE

network

This command sets the IPv6 address and mask for the subnet from which the pool of IP addresses will be allocated.

The use of a negative form (no) of the command removes subnet settings in pool.

Syntax
network <IPV6-ADDR/LEN>
no network
Parameters

<IPV6-ADDR/LEN> – IP address and prefix of a subnet, defined as X:X:X:X::X/EE where each X part takes values in hexadecimal format [0..FFFF] and EE takes values of [1..128].

Required privilege level

10

Command mode

CONFIG-IPV6-DHCP-SERVER

Example
esr(config-ipv6-dhcp-server)# network fc00::/110
CODE

option

This command specifies DHCP options.

The use of a negative form (no) of the command removes this option.

Syntax
option <CODE> { ip-address <IPV6-ADDR> | ascii-text <STRING> | hex-bytes <HEX> } 
no option { <CODE> | all }
Parameters

<CODE> – DHCP option code, set in the form of a number [1..255].

<HEX> – vendor-specific information, specified in hexadecimal format up to 255 symbols.

<IPV6-ADDR> – IPv6 address, defined as X:X:X:X::X where each part takes values in hexadecimal format [0..FFFF]. You can specify up to 8 IP addresses separated by commas.

<URL> – reference address, set by the string from 1 to 255 characters.

all – removes all options.

Default value

None

Required privilege level

10

Command mode

CONFIG-IPV6-DHCP-SERVER

Example
esr(config-ipv6-dhcp-server)# option 43 ip-address fc00::/110
CODE

show ipv6 dhcp binding

This command displays the IPv6 addresses issued by the DHCP server.

Syntax
show ipv6 dhcp binding [ <IPV6-ADDR> ]
Parameters

<IPV6-ADDR> – DHCP server IPv6 address, defined as X:X:X:X::X where each part takes values in hexadecimal format [0..FFFF]. If the <IPV6-ADDR> parameter is specified in the command, then information associated only with the specified address will be displayed.

Required privilege level

1

Command mode

ROOT

Example
esr# show ipv6 dhcp binding
IPv6 address                                          Lease expires at
---------------------------------------------------   ---------------------------
2001:db8:0:1::18                                      Tuesday 2015/06/09 23:39:45
CODE

show ipv6 dhcp server pool

This command displays configured IPv6 address pools. When specifying a name, only information for the specified pool is displayed.

Syntax
show ipv6 dhcp server pool [ <POOL_NAME> ]
Parameters

<NAME> – NAT addresses pool name, set by the string of up to 31 characters.

Required privilege level

1

Command mode

ROOT

Example
esr# show ipv6 dhcp server pool lan-pool-ipv6
name:               lan-pool-ipv6
network:            fc00::/110
domain name:        example.com
address-ranges:     fc00::1-fc00::2
                           fc00::3
addresses:          --
dns-server:         fc00:2::3
max lease time:     001:00:00 (day:hour:min)
default lease time: 000:12:00 (day:hour:min)
CODE

show ipv6 dhcp server vendor-specific

This command displays configured DHCP options 43 and 60.

Syntax
show ipv6 dhcp server vendor-specific
Parameters

The command does not contain parameters.

Required privilege level

1

Command mode

ROOT

Example
esr# show ipv6 dhcp server vendor-specific
Vendor ID          Vendor options
----------------   --------------------------------
 ELTEX             0x0b0931302e312e39302e32
CODE