The documentation set for this product strives to use bias-free language. For the purposes of this documentation set, bias-free is defined as language that does not imply discrimination based on age, disability, gender, racial identity, ethnic identity, sexual orientation, socioeconomic status, and intersectionality. Exceptions may be present in the documentation due to language that is hardcoded in the user interfaces of the product software, language used based on RFP documentation, or language that is used by a referenced third-party product. Learn more about how Cisco is using Inclusive Language.
This chapter contains the following sections:
To delete all dynamic IP entries or a specific IP entry from the ARP cache, use the clear arp-cache Privileged EXEC mode command.
clear arp-cache [ip-address]
ip-address—(Optional) The IP address to be deleted.
Privileged EXEC mode
switchxxxxxx# clear arp-cacheTo define a default gateway, use the ip default-gateway Global Configuration mode command.
To revert to its default setting, use the no form of this command.
ip default-gateway IPv4-ADDR
no ip default-gateway
IPv4-ADDR—IPv4 address of the default gateway.
No default gateway is defined.
Global Configuration mode
switchxxxxxx(config)# ip default-gateway 192.168.1.100To enable the IP Domain Naming System (DNS)-based host-name-to-address translation, use the ip domain lookup Global Configuration mode command.
To revert to its default setting, use the no form of this command.
ip domain lookup
no ip domain lookup
N/A
Enabled
Global Configuration mode
This command enables the switch to query domain name for DNS server.
switchxxxxxx(config)# ip domain loopkupTo define a default domain name that the switch uses to complete unqualified host names, use the ip domain name Global Configuration mode command.
To delete the static-defined default domain name, use the no form of this command.
ip domain name hostname
no ip domain name
hostname—Default domain name used to complete unqualified host names. Do not include the initial period that separates an unqualified name from the domain name. Length: 1 to 255 characters. Maximum label length of each domain level is 63 characters.
No default domain name is defined.
Global Configuration mode
Any IP hostname that does not contain a domain name (that is, any name without a dot) will have the dot and the default domain name appended to it before being added to the host table.
Domain names and hostnames are restricted to the ASCII letters A through Z (case-insensitive), the digits 0 through 9, the underscore and the hyphen. A period (.) is used to separate labels.
The maximum size of each domain level is 63 characters. The maximum name size is 255 bytes.
switchxxxxxx(config)# ip domain name website.comTo define the static host-name-to-address mapping in the DNS hostname cache, use the ip host Global Configuration mode command
To remove the static-host name-to-address, use the no form of this command.
ip host hostname address1 [address2...address8]
no ip host hostname address1 [address2...address8]
Parameters
hostname—Name of the host. (Length: 1 to 158 characters. Maximum label length of each domain level is 63 characters.)
address1—Associated host IP address (IPv4 or IPv6, if IPv6 stack is supported).
address2...address8—(Optional) Up to seven additional associated IP addresses, delimited by a single space (IPv4 or IPv6, if IPv6 stack is supported).
No host is defined.
Global Configuration mode
Hostnames are restricted to ASCII letters A through Z (case-insensitive), the digit 0 through 9, the underscore and the hyphen symbols. A period (.) is used to separate labels.
An IP application will receive the IP addresses in the following order:
IPv6 addresses in the order specified by the command.
IPv4 addresses in the order specified by the command.
Use the no format of the command with the address1...address8 argument to delete the specified addresses. The entry is deleted if all its addresses are deleted.
switchxxxxxx(config)# ip host accounting.website.com 176.10.23.1To configure the DNS servers, use the ip name-server Global Configuration mode command.
To disable the DNS servers, use the no form of this command.
ip name-server server-address1 [server-address2...server-address8]
no ip name-server
server-address1—IPv4 or IPv6 addresses of a single name server.
server-address2...server-address8—(Optional) IPv4 or IPv6 addresses of additional name servers.
No DNS server is configured.
Global Configuration mode
switchxxxxxx(config)# ip name-server 192.168.1.20
switchxxxxxx(config)# ip name-server 192.168.1.20 192.168.1.50To define the IP address for the management VLAN, use the management vlan ip-address Global Configuration mode command.
management vlan ip-address ip-address mask mask
ip-address—The IP address.
mask—The network mask of the IP address.
The default IP address of the management VLAN is 192.168.1.254.
Global Configuration mode
If a dynamic IP address is already defined, the user must enter the no management ip dhcp client command to disable it before setting a static IP address.
If you modify the static IP address, enter the no management ip dhcp client command to automatically add.
The following example configures the management VLAN with IP address 131.108.1.27 and subnet mask 255.255.255.0:
switchxxxxxx(config)# management vlan ip address 131.108.1.27 mask 255.255.255.0To acquire an IP address for the management VLAN from the DHCP server, use the management vlan ip dhcp client Global Configuration mode command.
To release an acquired IP address, use the no form of this command.
management vlan ip dhcp client
no management vlan ip dhcp client
N/A
DHCP client is enabled.
Global Configuration mode
This command enables the switch to dynamically learn its IP address by using the DHCP protocol.
DHCP client configuration on the switch implicitly removes the static IP address configuration on the management VLAN.
If the switch is configured to obtain its IP address from a DHCP server, it sends a DHCPDISCOVER message to provide information about itself to the DHCP server on the network.
The no management vlan ip dhcp client command releases any IP address that was acquired, and sends a DHCPRELEASE message.
switchxxxxxx(config)# management vlan ip dhcp clientTo display all entries in the ARP table, use the show arp Privileged EXEC mode command.
show arp
N/A
Privileged EXEC mode
switchxxxxxx# show arp
Address HWtype HWaddress Flags Mask Iface
192.168.1.22 ether 00:10:60:DB:6E:FE C eth0To display the DNS servers defined on the switch, use the show hosts Privileged EXEC mode command.
show hosts
N/A
Privileged EXEC mode
switchxxxxxx# show hosts
Name/address lookup is enabled
Default Domain Table
Domain Source Preference
--------------------------------------------- --------- ----------
Name Server Table
IP Address Source Preference
--------------------------------------------- --------- ----------
Cache Table
Flags: (STA, OK)
STA - Static
OK - Okay
Host IP Address Type State
------------------------- ------------------------ --------- --------To display the IP address of the management VLAN, use the show ip Privileged EXEC mode command.
show ip
N/A
N/A
Privileged EXEC mode
switchxxxxxx# show ip
IP Address: 192.168.1.254
Subnet Netmask: 255.255.255.0
Default Gateway: 192.168.1.1To display the IP DHCP status, use the show ip dhcp Privileged EXEC mode command.
show ip dhcp
N/A
N/A
Privileged EXEC mode
switchxxxxxx# show ip dhcp
DHCP Status : disabled
Feedback