Commands For Dhcp

7.1 Commands for DHCP

7.1.1 Commands for DHCP Server Configuration

7.1.1.1 bootfile

Command: bootfile <filename>
no bootfile
Function: Sets the file name for the DHCP client to import on boot up. The no command deletes this setting.
Parameters:

  • <filename>: name of the file to be imported, up to 255 characters are allowed.

Command mode: DHCP Address Pool Mode
Default: None.
Usage guide: Specify the name of the file to be imported for the client. This is usually used for diskless workstations that need to download a configuration file from the server on boot up. This command is used with ?next sever?.
Example: The path and filename for the file to be imported is ?c:tempnos.img?.

active500EM(dhcp-1-config)#bootfile c:tempnos.img

Related Command: next-server
 

7.1.1.2 clear ip dhcp binding

Command: clear ip dhcp binding {<address> | all}
Function: Deletes the specified IP address (hardware address) binding record or all IP addresses (hardware address) binding records.
Parameters:

  • <address>: the IP address that has a binding record. The format of this parameter is in decimal format.
  • all: refers to all IP addresses that have a binding record.

Command mode: Admin Mode
Default: None.
Usage guide: The ?show ip dhcp binding? command can be used to view binding information for IP addresses and corresponding DHCP client hardware addresses. If, before the lease expires, the DHCP server is notified that a DHCP client is not using the assigned IP address, the DHCP server would not automatically remove the binding information. The system administrator can use this command to delete that IP address (client hardware address) binding manually, if ?all? is specified. If ?all? is specified, all auto binding records will be deleted and all addresses in the DHCP address pool will be reallocated.
Example: Remove all IP-hardware address binding records.

active500EM#clear ip dhcp binding all

Related Command: show ip dhcp binding
 

7.1.1.3 clear ip dhcp conflict

Command: clear ip dhcp conflict {<address> | all }
Function: Deletes an address in the address conflict log.
Parameters:

  • <address>: IP address that has a record conflict.
  • all: represents for all addresses that have record conflicts.

Command mode: Admin Mode
Default: None.
Usage guide: The ?show ip dhcp conflict? command can be used to check which IP addresses are in conflict. The ?clear ip dhcp conflict? command can be used to delete the record conflict for an address. If ?all? is specified, all record conflicts in the log will be removed. When records are removed from the log, the addresses are available for allocation by the DHCP server.
Example: 10.1.128.160 is identified as having a record conflict in the log. The record is not used and is deleted from the address conflict log.

active500EM#clear ip dhcp conflict 10.1.128.160

Related Commands: ip dhcp conflict logging, show ip dhcp conflict
 

7.1.1.4 clear ip dhcp server statistics

Command: clear ip dhcp server statistics
Function: Deletes the statistics for the DHCP server, clears the DHCP server count.
Parameters: None.
Command mode: Admin Mode
Default: None.
Usage guide: DHCP count statistics can be viewed with the ?show ip dhcp server statistics? command, all information is accumulated. The ?clear ip dhcp server statistics? command can be used to clear the count for easier statistic verification.
Example: Clear the DHCP server count.

active500EM#clear ip dhcp server statistics

Related Command: show ip dhcp server statistics
 

7.1.1.5 client-identifier

Command: client-identifier <unique-identifier>
no client-identifier
Function: Specifies the unique ID of the user when binding an address manually. The no command deletes the identifier.
Parameters:

  • <unique-identifier>: user identifier. The valid format is dotted hex format.

Command mode: DHCP Address Pool Mode
Default: None.
Usage guide: This command is used with ?host? when binding an address manually. If the requesting client identifier matches the specified identifier, the DHCP server assigns the IP address defined in the ?host? command to the client.
Example: Specify the IP address 10.1.128.160 to be bound to the user with the unique ID of 00-10-5a-60-af-12 using manual address binding.

active500EM(dhcp-1-config)#client-identifier 00-10-5a-60-af-12
active500EM(dhcp-1-config)#host 10.1.128.160 24

Related Command: host
 

7.1.1.6 debug ip dhcp client

Command: debug ip dhcp client {event | packet}
no debug ip dhcp server {event | packet}
Function: Enable DHCP client debugging. The no command disables DHCP client debugging.
Parameters: None.
Command mode: Admin Mode
Default: Disable debugging.
Usage guide: Enables DHCP client debugging.
Example: Enable DHCP client debugging.

active500EM#debug ip dhcp client packet

 

7.1.1.7 debug ip dhcp relay

Command: debug ip dhcp relay packet
no debug ip dhcp relay packet
Function: Enable DHCP relay debugging. The no command disables DHCP relay debugging.
Parameters: None.
Command mode: Admin Mode
Default: Disable the debugging.
Usage guide: Enables DHCP relay debugging.
Example: Enable DHCP relay debugging.

active500EM#debug ip dhcp relay packet

 

7.1.1.8 debug ip dhcp server

Command: debug ip dhcp server { events | linkage | packets }
no debug ip dhcp server { events | linkage | packets }
Function: Enable DHCP server debugging. The no command disables DHCP server debugging.
Parameters: None.
Command mode: Admin Mode
Default: Disabled.
Usage guide: Enables DHCP server debugging.
Example: Enable DHCP server debugging.

active500EM#debug ip dhcp server packets

 

7.1.1.9 default-router

Command: default-router <address1>[<address2>[?<address8>]] no default-router
Function: Configures the default gateway(s) for DHCP clients. The no command deletes the default gateway.
Parameters:

  • <address1>?<address8>: IP addresses in decimal format.

Command mode: DHCP Address Pool Mode
Default: No default gateway is configured for DHCP clients.
Usage guide: The IP address of default gateway(s) should be in the same subnet as the DHCP client IP. The switch supports up to 8 gateway addresses. The first gateway address assigned has the highest priority. Therefore, address1 has the highest priority, address2 has the second, etc.
Example: Configure the default gateway for DHCP clients to 10.1.128.2 and 10.1.128.100.

active500EM(dhcp-1-config)#default-router 10.1.128.2 10.1.128.100

 

7.1.1.10 dns-server

Command: dns-server <address1>[<address2>[?<address8>]] no dns-server
Function: Configure DNS servers for DHCP clients. The no command deletes the default gateway.
Parameters:

  • <address1>?<address8>: IP addresses in decimal format.

Command mode: DHCP Address Pool Mode
Default: No DNS server is configured for DHCP clients.
Usage guide: Up to 8 DNS server addresses can be configured. The first DNS server address assigned has the highest priority. Address 1 has the highest priority, address 2 has the second highest priority, etc.
Example: Set 10.1.128.3 as the DNS server address for DHCP clients.

active500EM(dhcp-1-config)#dns-server 10.1.128.3

 

7.1.1.11 domain-name

Command: domain-name <domain>
no domain-name
Function: Configures the Domain name for DHCP clients. The no command deletes the domain name.
Parameters:

  • <domain>: the domain name. Up to 255 characters are allowed

Command mode: DHCP Address Pool Mode
Default: None.
Usage guide: Specifies a domain name for the client.
Example: Specify ?att.com? as the DHCP clients? domain name.

active500EM(dhcp-1-config)#domain-name att.com

 

7.1.1.12 hardware-address

Command: hardware-address <hardware-address> [{Ethernet | IEEE802|<type-number>}] no hardware-address
Function: Specifies the user hardware address when manually binding the address. The no command deletes the setting.
Parameters:

  • <hardware-address>: the hardware address in hex.
  • Ethernet | IEEE802: the Ethernet protocol type.
  • <type-number>: the RFC number defined for protocol types. Valid values are from 1 to 255. For example, 0 for Ethernet and 6 for IEEE 802.

Command mode: DHCP Address Pool Mode
Default: The default protocol type is Ethernet.
Usage guide: This command is used with the ?host? when binding the address manually. If the requesting client hardware address matches the specified hardware address, the DHCP server assigns the IP address defined in the ?host? command to the client
Example: Specify the IP address of 192.168.1.160 to be bound to the user with a hardware address of 00-00-e2-3a-26-04 via manual address binding.

active500EM(dhcp-1-config)#hardware-address 00-00-e2-3a-26-04
active500EM(dhcp-1-config)#host 192.168.1.160 24

Related command: host
 

7.1.1.13 host

Command host <address> [<mask> | <prefix-length>] no host
Function: Specifies the IP address to be assigned to the user when manually binding addresses. The no command deletes the IP address.
Parameters:

  • <address>: the IP address in decimal format.
  • <mask>: the subnet mask in decimal format.
  • <prefix-length>: identifies that the mask is indicated by a prefix. For example, for the mask 255.255.255.0, the prefix is ?24?. For the mask 255.255.255.252, the prefix is ?30?.

Command mode: DHCP Address Pool Mode
Default: None.
Usage guide: If no mask or prefix is configured when configuring the IP address, and no information in the IP address pool refers to the mask, the system will automatically assign a mask according to the IP address class. This command is used with the ?hardware address? command or ?client identifier? command when binding addresses manually. If the identifier (or hardware address) of the requesting client matches the specified identifier (or hardware address), the DHCP server assigns the IP address defined in the ?host? command to the client.
Example: Specify IP address of 192.168.1.160 to be bound to the user with a hardware address of 00-10-5a-60-af-12 to manually bind the address.

active500EM(dhcp-1-config)#hardware-address 00-10-5a-60-af-12
active500EM(dhcp-1-config)#host 192.168.1.160 24

Related commands: hardware-address, client-identifier
 

7.1.1.14 ip dhcp conflict logging

Command: ip dhcp conflict logging
no ip dhcp conflict logging
Function: Enables logging for address conflicts detected by the DHCP server. The no command disables the logging.
Parameters: None.
Command mode: Global Mode
Default: Enabled.
Usage guide: When logging is enabled and once the address conflict is detected by the DHCP server, the conflicting address will be logged. Addresses present in the log for conflicts will not be assigned dynamically by the DHCP server until the conflicting records are deleted.
Example: Disable logging for the DHCP server.

active500EM(config)#no ip dhcp conflict logging

Related Command: clear ip dhcp conflict
 

7.1.1.15 ip dhcp disable

Command: ip dhcp disable
no ip dhcp disable
Function: Disables the DHCP service on a particular interface.
Parameters: None.
Command mode: Interface Mode
Default: None.
Usage guide: This command is used to disable the DHCP services on the particular interface/port of the controller.
Example: Users can pinpoint a certain Ethernet port of a VLAN and can disable DHCP service for only that port while keeping it available to other ports of the same VLAN

active500EM(config)#interface ethernet 1/0/10
active500EM(config-if-ethernet1/0/10)#ip dhcp disable

 

7.1.1.16 ip dhcp excluded-address

Command: ip dhcp excluded-address <low-address> [<high-address>] no ip dhcp excluded-address <low-address> [<high-address>] Function: Specifies addresses excluded from dynamic assignment. The no command cancels the setting.
Parameters:

  • <low-address>: starting IP address.
  • <high-address>: ending IP address.

Command mode: Global Mode
Default: Only an individual address is excluded.
Usage guide: This command can be used to exclude one or several consecutive addresses in the pool from being assigned dynamically so that those addresses can be used by the administrator for other purposes.
Example: Reserve addresses from 10.1.128.1 to 10.1.128.10 from dynamic assignment.

active500EM(config)#ip dhcp excluded-address 10.1.128.1 10.1.128.10

 

7.1.1.17 ip dhcp pool

Command: ip dhcp pool <name>
no ip dhcp pool <name>
Function: Configures a DHCP address pool and enters pool mode. The no command deletes the specified address pool.
Parameters:

  • <name>: the address pool name. Up to 32 characters are allowed.

Command mode: Global Mode
Default: None.
Usage guide: This command is used to configure a DHCP address pool under Global Mode.
Example: Define an address pool named ?1?.

active500EM(config)#ip dhcp pool 1
active500EM(dhcp-1-config)#

 

7.1.1.18 ip dhcp conflict ping-detection enable

Command: ip dhcp conflict ping-detection enable
no ip dhcp conflict ping-detection enable
Function: Enable conflict Ping-detection on the DHCP server. The no command disables the function.
Parameters: None.
Command mode: Global Configuration Mode
Default: Disabled.
Usage guide: To enable conflict Ping-detection, one should enable the conflict address log. If the conflict address log is disabled, conflict Ping-detection will also be disabled. When a client is unable to receive Ping request messages (when blocked by a firewall, for example), this function will check local ARP according to the allocated IP. If a designated IP has a corresponding ARP, then an address conflict exists. Otherwise, it will be allocated to the client.
Example: Enable conflict Ping-detection.

active500EM(config)#ip dhcp conflict ping-detection enable

Related Commands: ip dhcp conflict logging, ip dhcp ping packets, ip dhcp ping timeout
 

7.1.1.19 ip dhcp ping packets

Command: ip dhcp ping packets <request-num>
no ip dhcp ping packets
Function: Set the maximum number of Ping request (Echo Request) messages to be sent in conflict Ping-detection on the DHCP server. The default value is 2. The no command restores the default value.
Parameters:

  • <request-num>: number of ping request messages to be sent in conflict Ping-detection.

Command mode: Global Configuration Mode
Default: No more than 2 ping request messages will be sent.
Usage guide: Set the maximum number of ping request (Echo Request) messages to be sent in conflict Ping-detection on the DHCP server.
Example: Set the maximum number of pPing request (Echo Request) messages to be sent in conflict Ping-detection on the DHCP server to 3.

active500EM(config)#ip dhcp ping packets 3

Related Commands: ip dhcp conflict ping-detection enable, ip dhcp ping timeout
 

7.1.1.20 ip dhcp ping timeout

Command: ip dhcp ping timeout <timeout-value>
no ip dhcp ping timeout
Function: Set the waiting timeout period in milliseconds (ms) for a reply message (echo request) after each ping request message (echo request) in conflict Ping-detection on the DHCP server. The no command restores the default value.
Parameters:

  • <timeout-value>: waiting timeout period for a reply message after each ping request message in conflict Ping-detection.

Command mode: Global Configuration Mode
Default: The timeout period is 500ms.
Usage guide: Sets the waiting timeout period in milliseconds (ms) for a reply message (echo request) after each ping request message (echo request) in conflict Ping-detection on the DHCP server.
Example: Set the waiting timeout period (in ms) for each reply message (echo request) in conflict Ping-detection on the DHCP server to 600ms.

active500EM(config)# ip dhcp ping time out 600

Related Commands: ip dhcp conflict ping-detection enable, ip dhcp ping packets
 

7.1.1.21 lease

Command: lease { [<days>] [<hours>][<minutes>] | infinite }
no lease
Function: Sets the lease time for addresses in the address pool. The no command restores the default setting.
Parameters:

  • <days>: the number of days from 0 to 365.
  • <hours>: number of hours from 0 to 23.
  • <minutes>: number of minutes from 0 to 59.
  • infinite: perpetual use.

Command mode: DHCP Address Pool Mode
Default: The default lease duration is 1 day.
Usage guide: DHCP is the protocol to assign network addresses dynamically instead of permanently. Lease settings should be decided upon based on network conditions. A lease duration that is too long offsets the flexibility of DHCP. A lease duration that is too short results in increased network traffic and overhead. The default lease duration for the switch is 1 day.
Example: Set the lease of DHCP pool ?1? to 3 days 12 hours and 30 minutes.

active500EM(dhcp-1-config)#lease 3 12 30

 

7.1.1.22 max-lease-time

Command: max-lease-time {[<days>] [<hours>] [<minutes>] | infinite}
no max-lease-time
Function: Set the maximum lease time for the addresses in the address pool. The no command restores the default setting.
Parameters:

  • <days>: number of days from 0 to 365.
  • <hours>:number of hours from 0 to 23.
  • <minutes>: number of minutes from 0 to 59.
  • infinite: perpetual use.

Command mode: DHCP Address Pool Mode
Default: The default lease time is 1 day.
Usage guide: This command is used for DHCP request packets with option51. If the lease time requested by the user exceeds the maximum configured lease time, the lease that the DHCP server assigns to the address becomes the maximum configured lease time. If the lease time requested by the user is less than the maximum configured lease time, the user requested lease time is used by the DHCP server. The maximum lease time is set by the administrator according to the actual conditions of the network. The maximum lease time is set to 1 day by default.
Example: Set the maximum lease time of the DHCP address pool1 to 3 days 12 hours and 30 minutes.

active500EM(dhcp-1-config)#max-lease-time 3 12 30

 

7.1.1.23 netbios-name-server

Command: netbios-name-server <address1>[<address2>[?<address8>]] no netbios-name-server
Function: Configures the WINS server address. The no command deletes the WINS server.
Parameters:

  • <address1>?<address8>: IP addresses in decimal format.

Command mode: DHCP Address Pool Mode
Default: No WINS server.
Usage guide: This command is used to specify the WINS server for the client. Up to 8 WINS server addresses can be configured. The first WINS server address assigned has the highest priority. Therefore, address 1 has the highest priority, address 2 the second highest priority, etc.
Example: Set the server address of DHCP pool ?1? to 192.168.1.1.

active500EM(dhcp-1-config)#netbios-name-server 192.168.1.1

 

7.1.1.24 netbios-node-type

Command: netbios-node-type {b-node | h-node | m-node | p-node | <type-number>}
no netbios-node-type
Function: Set the node type for the specified port. The no command cancels the setting.
Parameters:

  • b-node: broadcasting node.
  • h-node: hybrid node that broadcasts after point-to-point communication.
  • m-node: hybrid node to communicate in point-to-point after the broadcast.
  • p-node: point-to-point node.
  • <type-number>: node type in hex with valid values from 0 to FF.

Command mode: DHCP Address Pool Mode
Default: No client node type is specified.
Usage guide: If the client node type is to be specified, it is recommended that the client node type is set to h-node which broadcasts after point-to-point communication.
Example: Set the node type for the client of pool 1 to broadcast node.

active500EM(dhcp-1-config)#netbios-node-type b-node

 

7.1.1.25 network-address

Command: network-address <network-number> [<mask> | <prefix-length>] no network-address
Function: Sets the scope for the assignment of addresses in the pool. The no command cancels the setting.
Parameters:

  • <network-number>: the network number.
  • <mask>: the subnet mask in decimal format.
  • <prefix-length>: mask in prefix form. For example, the prefix is ?24? in the mask 255.255.255.0. The prefix is ?30? in the mask 255.255.255.252. When using DHCP server, the pool mask should be longer or equal to the Layer 3 interface IP address in the corresponding segment.

Command mode: DHCP Address Pool Mode
Default: If no mask is specified, a default mask will be assigned according to the address class.
Usage guide: This command sets the scope of addresses that can be used for dynamic DHCP server assignment. One address pool can have only one corresponding segment. This command is exclusive to the manual address binding command of ?hardware address? and ?host?.
Example: Configure the assignable address in pool1 to be 192.168.1.0/24.

active500EM(dhcp-1-config)#network-address 192.168.1.0 24

 

7.1.1.26 next-server

Command: next-server <address1>[<address2>[?<address8>]] no next-server
Function: Set the server address for storing the client import file. The no command cancels the setting.
Parameters:

  • <address1>?<address8>: IP addresses. The valid format is decimal format.

Command mode: DHCP Address Pool Mode
Default: None.
Usage guide: This command configures the address for the server hosting client import file. This is usually used for diskless workstations that need to download configuration files from the server on boot up. This command is used with ?bootfile?.
Example: Set the hosting server address to 10.1.128.4.

active500EM(dhcp-1-config)#next-server 10.1.128.4

 

7.1.1.27 option

Command: option <code> {ascii <string> | hex <hex> | ipaddress <ipaddress>}
no option <code>
Function: Set the network parameter specified by the option code. The no command cancels the setting.
Parameters:

  • <code>: code for network parameters.
  • <string>: ASCII string up to 255 characters.
  • <hex>: a value in hex that is no greater than 510 and must be of even length.
  • <ipaddress>: IP address. The valid format is decimal format. Up to 63 IP addresses can be configured.

Command mode: DHCP Address Pool Mode
Default: None.
Usage guide: The switch provides common commands for network parameter configuration as well as various commands useful in network configuration to meet different user needs.
Example: Set the WWW server address to 10.1.128.240.

active500EM(dhcp-1-config)#option 72 ip 10.1.128.240

 

7.1.1.28 service dhcp

Command: service dhcp
no service dhcp
Function: Enables the DHCP server. The no command disables the DHCP service.
Parameters: None.
Command mode: Global Mode
Default: DHCP service is disabled.
Usage guide: Both DHCP server and DHCP relay are included in the DHCP service. When DHCP services are enabled, both DHCP server and DHCP relay are enabled. The switch assigns the IP address for the DHCP clients and enables DHCP relay when the DHCP server function is enabled.
Example: Enable the DHCP server.

active500EM(config)#service dhcp

 

7.1.1.29 show ip dhcp binding

Command: show ip dhcp binding [[<ip-addr>] [type {all | manual | dynamic}] [count] Function: Displays IP-MAC binding information.
Parameters:

  • <ip-addr>: a specified IP address in decimal format.
  • all: all binding types (manual binding and dynamic assignment).
  • manual: manual binding.
  • dynamic: dynamic assignment.
  • count: displays statistics for the binding DHCP address entries.

Command mode: Admin and Configuration Mode
Default: None.
Usage guide: Display IP-MAC binding information.
Example: Display IP-MAC binding information.

active500EM#show ip dhcp binding.
IP address      Hardware address       Lease expiration     Type
10.1.1.233      00-00-E2-3A-26-04      Infinite             Manual
10.1.1.254      00-00-E2-3A-5C-D3      60                   Automatic
Displayed information Explanation
IP address IP address assigned to a DHCP client
Hardware address MAC address of a DHCP client
Lease expiration Valid time for the DHCP client to hold the IP address
Type Type of assignment: manual binding or dynamic assignment.

 

7.1.1.30 show ip dhcp conflict

Command: show ip dhcp conflict
Function: Displays the log information for addresses with records that conflict.
Parameters: None.
Command mode: Admin and Configuration Mode
Default: None.
Usage guide: Displays the log information for addresses with records that conflict.
Example: Display the log information for addresses with records that conflict.

active500EM# show ip dhcp conflict
IP Address        Detection method      Detection Time
10.1.1.1          Ping                  FRI JAN 02 00:07:01 2002
Displayed information Explanation
IP Address Conflicting IP address
Detection method Method in which the conflict is detected.
Detection Time Time when the conflict is detected.

 

7.1.1.31 show ip dhcp relay information option

Command: show ip dhcp relay information option
Function: Show the relative configuration for DHCP relay option82.
Parameters: None.
Command mode: Admin and Configuration Mode
Default: None.
Usage guide: Shows the relative configuration for DHCP relay option82.
Example: Set the admin mode timeout value to 6 minutes.

active500EM#show ip dhcp relay information option
ip dhcp server relay information option(i.e. option 82) is enabled
ip dhcp relay information option(i.e. option 82) is enabled

 

7.1.1.32 show ip dhcp server statistics

Command show ip dhcp server statistics
Function: Displays all DHCP packet statistics for a DHCP server.
Parameters: None.
Command mode: Admin and Configuration Mode
Default: None.
Usage guide: Displays all DHCP packet statistics for a DHCP server.
Example: Display all DHCP packets statistics for the DHCP server.

active500EM# show ip dhcp server statistics
Address pools	        3
Database agents	        0
Automatic bindings	2
Manual bindings  	0
Conflict bindings	0
Expired bindings	0
Malformed message	0
Message	                Received
BOOTREQUEST	        3814
DHCPDISCOVER	        1899
DHCPREQUEST     	6
DHCPDECLINE	        0
DHCPRELEASE	        1
DHCPINFORM	        1
Message	                Send
BOOTREPLY	        1911
DHCPOFFER	        6
DHCPACK	                6
DHCPNAK	                0
DHCPRELAY	        1907
DHCPFORWARD	        0
Displayed information Explanation
Address pools Number of DHCP address pools configured
Database agents Number of database agents
Automatic bindings Number of addresses assigned automatically
Manual bindings Number of addresses bound manually
Conflict bindings Number of conflicting addresses
Expired bindings Number of addresses whose leases are expired
Malformed message Number of error messages
Message Received Statistics for DHCP packets received
BOOTREQUEST Total packets received
DHCPDISCOVER Number of DHCPDISCOVER packets
DHCPREQUEST Number of DHCPREQUEST packets
DHCPDECLINE Number of DHCPDECLINE packets
DHCPRELEASE Number of DHCPRELEASE packets
DHCPINFORM Number of DHCPINFORM packets
Message Send Statistics for DHCP packets sent
BOOTREPLY Total packets sent
DHCPOFFER Number of DHCPOFFER packets
DHCPACK Number of DHCPACK packets
DHCPNAK Number of DHCPNAK packets
DHCPRELAY Number of DHCPRELAY packets
DHCPFORWARD Number of DHCPFORWARD packets

 

7.1.2 Commands for DHCP Relay Configuration

7.1.2.1 ip dhcp broadcast suppress

Command: ip dhcp broadcast suppress
no ip dhcp broadcast suppress
Function: Enable DHCP broadcast suppress function. The no command disables the function.
Parameters: None.
Command mode: Global Mode
Default: Disabled.
Usage guide: Suppress DHCP broadcast packet forwarding. Namely, drop or copy DHCP broadcast packets to the CPU.
Example: Enable the DHCP broadcast suppress function.

active500EM(config)#ip dhcp broadcast suppress

 

7.1.2.2 ip dhcp relay share-vlan sub-vlan

Command: ip dhcp relay share-vlan <vlanid> sub-vlan <vlanlist>
no ip dhcp relay share-vlan <vlanid>
Function: Share the DHCP through relay to a sub VLAN.
Parameters:

  • <vlanid>: VLAN ID of the shared VLAN.
  • <vlanlist>: VLAN ID of the sub VLAN.

Command mode: Global Mode
Default: Disabled.
Usage guide: Provides DHCP information and services to the sub VLAN.
Example: Share the DHCP through relay of Vlan1 to sub-Vlan2

active500EM(config)#ip dhcp relay share-vlan 1 sub-vlan 2

 

7.1.2.3 ip forward-protocol udp bootps

Command: ip forward-protocol udp bootps
no ip forward-protocol udp bootps
Function: Sets DHCP relay to forward UPD broadcast packets on the port. The no command cancels the forwarding.
Parameters:

  • bootps: forwarding UDP port (67 DHCP broadcast packets).

Command mode: Global Mode
Default: Do not forward UPD broadcast packets.
Usage guide: The forwarding destination address is set in the ?ip helper-address? command described later in this chapter.
Example: Set DHCP packets to be forwarded to 192.168.1.5.

active500EM(config)#ip forward-protocol udp bootps
active500EM(config)#interface vlan 1
active500EM(config-if-vlan1)#ip helper-address 192.168.1.5

 

7.1.2.4 ip helper-address

Command: ip helper-address <ip-address>
no ip helper-address <ip-address>
Function: Specifies the DHCP relay destination address in order to forward UDP packets. The no command cancels the setting.
Parameters:

  • <ip-address>: IP destination address.

Command mode: Interface Configuration Mode
Default: None.
Usage guide: The DHCP relay forwarding server address corresponds to the port forwarding UDP. For example, DHCP relay forwards corresponding UDP packets to the corresponding server instead of all UDP packets to all servers. When this command is run after the ?ip forward-protocol udp <port>? command, the forwarding address configured by this command receives the UDP packets from the <port>. The combination of the ?forward-protocol udp <port>? command and this command should be used for configuration.
Example: Specify the DHCP relay destination address in order to forward UDP packets.

active500EM(config)#interface vlan 1
active500EM(config-if-vlan1)#ip helper-address 192.168.1.5

 

7.1.2.5 show ip forward-protocol

Command: show ip forward-protocol
Function: Shows the DHCP packet forwarding port ID.
Parameters: None.
Command mode: Admin and Configuration Mode
Default: None.
Usage guide: Shows the DHCP packet forwarding port ID.
Example: Show the DHCP packet forwarding port ID.

active500EM#show ip forward-protocol
Forward protocol(UDP port): 67(active)

 

7.1.2.6 show ip helper-address

Command: show ip helper-address
Function: Display the configuration relation for the port ID of the protocol (it can forward broadcast packets), the interface (it supports forwarding function), and the forwarded destination IP.
Parameters: None.
Command mode: Admin and configuration Mode
Default: None.
Usage guide: Displays the configuration relation for the port ID of the protocol (it can forward broadcast packets), the interface (it supports forwarding function), and the forwarded destination IP.
Example: Displays the configuration relation for the port ID of the protocol, the interface, and the forwarded destination IP.

active500EM#show ip helper-address
Forward protocol     Interface           Forward server
67(active)           Vlan1               192.168.1.1

 


Return to Controller Wired CLI Table of Contents