GRÁFICO 1.7 MALLA TIPO “L”

Dynamic Host Configuration Protocol (DHCP) server commands are used to enable or disable the DHCP server, and create or delete a DHCP pool. Table 2-9. DHCP Server Commands (1 of 3)

[no] service dhcp

Minimum Access Level: Administrator Command Mode: config

Allows you to enable or disable the DHCP server. The DHCP server is enabled by default but is not active until other DHCP server options are configured. When an IP address is assigned to a host by the DHCP Server and there is no matching routing table entry, a host entry for that IP address is created. This entry is deleted from the routing table when the lease expires or the IP address is relinquished.

When an IP address is assigned to a host on the local Ethernet by the DHCP Server, an ARP table entry is created mapping that IP address to the corresponding host MAC address. This entry is deleted from the ARP table when the lease expires or the IP address is relinquished. This entry is not deleted according to the timeout mechanism that applies to normal ARP entries.

NOTE: The DHCP Relay and DHCP Server cannot be enabled at the same time.

[no] ip dhcp pool pool-name

Minimum Access Level: Administrator Command Mode: config

Allows you to create or delete a DHCP pool and places it in DHCP pool configuration mode to configure IP DHCP pool parameters. All commands entered while in DHCP pool configuration mode are applied to the specified DHCP pool. No DHCP pools are

configured by default.

Example: ip dhcp pool pool17

pool-name – The name of the DHCP pool, as 1–20 ASCII printable characters.

[no] ip dhcp excluded-address ip-addr [end-ip-addr]

Minimum Access Level: Administrator Command Mode: config

Allows you to specify a single IP address, or a range of IP addresses, that the DHCP server should not distribute to clients. The no ip dhcp excluded-address command allows you to release previously excluded IP addresses for distribution to clients. No IP addresses are excluded by default. Up to 30 individual or ranges of IP addresses are supported.

Example: ip dhcp excluded-address 132.53.4.2

ip-addr – Specifies an IP address to exclude, or the first IP address in a range of excluded IP addresses.

lease {days[hours] [minutes] | infinite} no lease [days[hours] [minutes ] |infinite]

Minimum Access Level: Administrator Command Mode: config-dhcp

Allows you to specify or clear the lease time for an IP address assigned to a DHCP client. After the lease time has expired, the address assignment is no longer valid. The default lease time is one day.

Example: lease 120 23 0

days – Number of days the lease is valid. The default is1. Valid range of days is 0–365. hours – Number of hours the lease is valid. The default is 0. Valid range for hours is 0–24.

minutes – Number of minutes the lease is valid. The default is 0. Valid range for minutes is 0–59.

infinite – Specifies an infinite lease time. The IP address assignment does not expire. default-router ip-address

no default-router [ip-address]

Minimum Access Level: Administrator Command Mode: config-dhcp

Allows you to configure or remove the default router IP address provided to clients by the DHCP server. The default router address is provided to the clients in the DHCP reply message from the DHCP server and as the next hop router by the clients. The IP address for the default router should be on the same subnet as the client.

Example: default-router 132.53.4.2

ip-address – Specifies the IP address of the default router. The default is None.

domain-name domain-name no domain-name [domain-name]

Minimum Access Level: Administrator Command Mode: config-dhcp

Allows you to specify or remove the domain name provided to clients by the DHCP server. This domain name is provided to the clients in the DHCP reply message from the DHCP server.

domain-name – Specifies a string defining the domain name. The domain name string contains 255 ASCII printable characters. The default is None.

dns-server ip-address no dns-server [ip-address]

Minimum Access Level: Administrator Command Mode: config-dhcp

Allows you to specify or remove the Domain Name System (DNS) IP address provided to clients by the DHCP server.

Example: dns-server 132.53.4.2

ip-address – Specifies the IP address of the DNS server. Table 2-9. DHCP Server Commands (2 of 3)

network network-num

[ [netmask ] netmask | {prefix-length | / } prefix-length] no network [network-num

[ [netmask] netmask | {prefix-length | / } prefix-length] ]

Minimum Access Level: Administrator Command Mode: config-dhcp

Allows you to specify or remove a subnet and subnet mask to a DHCP server pool. The configured subnet and subnet mask will specify the range of IP addresses that will be allocated to clients by the DHCP server. Only one network or subnet may be specified for a server pool.

Example: network 8

network-num – The IP address of the DHCP address pool.

netmask – Specify a network mask that indicates which address bits belong to the

network and subnet fields and which bits belong to the host field. netmask – The network mask for the pool of IP addresses.

prefix-length or / – Specify the number of bits in a network mask address that are ones

and define the network and subnet fields.

prefix-length – Number of ones bits in a network mask address. Valid range is 1–32. NOTES:

– If the mask or prefix-length is not specified, the class A, B, or C natural mask is used.

– When the DHCP address range is changed, all binding entries and dynamic routes for the clients configured with the old address range are removed.