DHCP
36
Models 2211 & 2232 Getting Started Guide
4 • IP address configuration
Static IP configuration
To configure IP configuration parameters of the device server, use
set
command as follows:
set ip static ip_address subnet_mask default_g <CR>
where,
ip_address = IP address of the device server
subnet_mask = Subnet mask
default_gateway = Default gateway IP address
To apply changes, users have to invoke
save
and
reboot
commands after changing configuration.
> set ip static 192.168.1.10 255.255.255.0 192.168.1.1
OK
DHCP
Dynamic Host Configuration Protocol (DHCP) is a communications protocol that allows network adminis-
trators to manage and automate the assignment of IP addresses centrally in an organization's network. DHCP
allows a network administrator to supervise and distribute IP addresses from a central point and automatically
send a new IP address when a computer is plugged into a different place in the network.
As described in the section 4.1, the IP address must be entered manually at each computer in Static IP mode
and, if computers move to another location in another part of the network, a new IP address must be entered.
Meanwhile, all the parameters including the IP address, subnet mask, gateway, DNS servers will be automati-
cally configured when the IP address is assigned in DHCP mode. DHCP uses the concept of a "lease" or
amount of time for which a given IP address will be valid for a computer. All the parameters required are
assigned by the DHCP server, and each DHCP client computer receives the proper network information
at boot-up.
To obtain an IP address, the device server sends a corresponding DHCP request as a broadcast over the net-
work after each reset. The reply generated by the DHCP server contains the IP address as well as the subnet
mask, gateway address, DNS servers and the lease time. The device server immediately places this information
in its non-volatile memory. If the operating time reaches the lease time, the device server will request the
DHCP server for renewal of its lease time. If the DHCP server approves extending the lease, the device server
can continue to work with the current IP address. Otherwise, the device server will start the procedure to
request a new IP address to the DHCP server.
A DHCP sever assigns IP addresses dynamically from an IP address pool, which is managed by the network
administrator. This means DHCP client, i.e. the device server, receives a different IP address each time it boots
up. To prevent the case that users do not know the IP address of the device server in such environments, its IP
address should be reserved on the DHCP server side. In order to reserve the IP address in the DHCP network,
the administrator needs the MAC address of the device server found on the label sticker at the bottom of the
device server:
MAC=00:0B:6B:19:16:9E
