Dynamic Host Configuration Protocol; Dhcp Relay Agent - HP GbE2c - Blc Layer 2/3 Fiber SFP Option Application Manual

3. Add each IP interface to the appropriate VLAN.
Now that the ports are separated into three VLANs, the IP interface for each subnet must be placed in the
appropriate VLAN. The settings are made as follows:
>> VLAN 3# /cfg/l3/if 1
>> IP Interface 1# vlan 2
>> IP Interface 1# ../if 2
>> IP Interface 2# vlan 1
>> IP Interface 2# ../if 3
>> IP Interface 3# vlan 1
>> IP Interface 3# ../if 4
>> IP Interface 4# vlan 3
4. Apply and verify the configuration.
>> IP Interface 4# apply
>> IP Interface 4# /info/vlan (View current VLAN information)
>> Information# port
Examine the resulting information. If any settings are incorrect, make the appropriate changes.
5. Save your new configuration changes.
>> Information# save

Dynamic Host Configuration Protocol

Dynamic Host Configuration Protocol (DHCP) is a transport protocol that provides a framework for automatically
assigning IP addresses and configuration information to other IP hosts or clients in a large TCP/IP network. Without
DHCP, the IP address must be entered manually for each network device. DHCP allows a network administrator to
distribute IP addresses from a central point and automatically send a new IP address when a device is connected to a
different place in the network.
DHCP is an extension of another network IP management protocol, Bootstrap Protocol (BOOTP), with an additional
capability of being able to dynamically allocate reusable network addresses and configuration parameters for client
operation.
Built on the client/server model, DHCP allows hosts or clients on an IP network to obtain their configurations from a
DHCP server, thereby reducing network administration. The most significant configuration the client receives from the
server is its required IP address; (other optional parameters include the "generic" file name to be booted, the address
of the default gateway, and so forth).
The DHCP relay agent eliminates the need to have DHCP/BOOTP servers on every subnet. It allows the administrator
to reduce the number of DHCP servers deployed on the network and to centralize them. Without the DHCP relay
agent, there must be at least one DHCP server deployed at each subnet that has hosts needing to perform the DHCP
request.

DHCP relay agent

DHCP is described in RFC 2131, and the DHCP relay agent supported on GbE2c switches is described in RFC 1542.
DHCP uses UDP as its transport protocol. The client sends messages to the server on port 67 and the server sends
messages to the client on port 68.
DHCP defines the methods through which clients can be assigned an IP address for a finite lease period and allowing
reassignment of the IP address to another client later. Additionally, DHCP provides the mechanism for a client to
gather other IP configuration parameters it needs to operate in the TCP/IP network.
In the DHCP environment, the switch acts as a relay agent. The DHCP relay feature (/cfg/l3/bootp) enables the
switch to forward a client request for an IP address to two BOOTP servers with IP addresses that have been
configured on the switch.
When a switch receives a UDP broadcast on port 67 from a DHCP client requesting an IP address, the switch acts as
a proxy for the client, replacing the client source IP (SIP) and destination IP (DIP) addresses. The request is then
forwarded as a UDP Unicast MAC layer message to two BOOTP servers whose IP addresses are configured on the
(Select IP interface 1 for def. routers)
(Set to VLAN 2)
(Select IP interface 2 for first floor)
(Set to VLAN 1)
(Select IP interface 3 for second floor)
(Set to VLAN 1)
(Select IP interface 4 for servers)
(Set to VLAN 3)
(Make your changes active)
(View current port information)
(Save for restore after reboot)
Basic IP routing 92