3Com 10014299 manual Low-ipaddress high-ipaddress, Low-ipaddress high -ipaddress

DHCP Server Configuration 339

The command network cannot be superimposed, that is, the latest configuration will overwrite the previous one.

The command network and the commands static-bindip-addressand static-bindmac-addressare conflicting. In other words, for the same DHCP address pool, configure either dynamically binding address or the dynamic address, but not both.

4Configure the IP Addresses in the DHCP Address Pool not participating in Auto-allocation

As for a network or subnetwork, some IP addresses may have been used by some servers or particular hosts, like WWW server, gateway and FTP server. The DHCP server should exclude these addresses to ensure the normal operation of the network when allocating addresses. Otherwise, there will be the possibility that one address is allocated to two hosts, and hence causes the IP address allocation conflict.

By default, no IP address that does not participate in the auto-allocation is configured. As for some IP addresses that do not participate in the allocation, use the dhcp server forbidden-ipcommand to avoid their allocations.

Perform the following configurations in system view.

Table 370 Configure the IP addresses in an address pool that do not participate in auto-allocation

Operation	Command
Configure the IP addresses in a DHCP address	dhcp server forbidden-ip
pool that will not participate in	low-ipaddress [ high-ipaddress ]
auto-allocation
Delete the IP addresses in a DHCP address	undo dhcp server forbidden-ip
pool that do not participate in auto-allocation	low-ipaddress [ high -ipaddress ]

By default, IP addresses that do not participate in auto-allocation are not configured. That is, all the addresses are assumed to participate in auto-allocation.

This command can be superimposed. That is, the latest and the original configurations will take effect simultaneously. When using the undo dhcp server forbidden-ipcommand to delete the address-excluding setting, make sure that the parameters are totally consistent with those originally configured. That is, do not delete only some addresses originally configured.

5Configure IP Address Leasing Valid Period for DHCP Address Pool

According to various purposes of client hosts, a DHCP server can specify different valid periods of address leasing for different address pools and thus enhance the application flexibility. All the addresses in the same DHCP address pool own the same valid period. Address leasing valid period can not be inherited.

Perform the following configurations in DHCP address pool view.

Table 371 Configure IP address leasing valid period for DHCP address pool

Operation	Command
Configure the leasing valid period of the dynamically	expired { day day [ hour
allocated IP address for a DHCP address pool	hour [ minute minute ] ]
	unlimited }
Restore the leasing valid period of the dynamically	undo expired
allocated IP address for the DHCP address pool to the
default value