3Com 3036, Configuration Manual

Page: 343 / 762

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-bind ip-address
and
static-bind mac-address
are conflicting. In other words, for the same DHCP
address pool, configure either dynamically binding address or the dynamic
address, but not both.
4 Configure 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-ip
command 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
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-ip
command 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.
5 Configure 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 IP addresses in a DHCP address
pool that will not participate in
auto-allocation
dhcp server forbidden-ip
low-ipaddress [ high-ipaddress ]
Delete the IP addresses in a DHCP address
pool that do not participate in auto-allocation
undo dhcp server forbidden-ip
low-ipaddress [ high -ipaddress ]
Operation Command
Configure the leasing valid period of the dynamically
allocated IP address for a DHCP address pool
expired { day day [ hour
hour [ minute minute ] ] |
unlimited
}
Restore the leasing valid period of the dynamically
allocated IP address for the DHCP address pool to the
default value
undo expired