Dhcp Packet Processing Modes; Protocols And Standards - 3Com 7757 Configuration Manual

592 C 56: DHCP O
HAPTER
DHCP Packet
Processing Modes
Protocols and
Standards
VERVIEW
After the DHCP server is enabled on a device, the device processes the DHCP
packet received from a DHCP client in one of the following three modes
depending on your configuration:
Global address pool: In response to the DHCP packets received from DHCP
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clients, the DHCP server picks IP addresses from its global address pools and
assigns them to the DHCP clients.
Interface address pool: In response to the DHCP packets received from DHCP
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clients, the DHCP server picks IP addresses from the interface address pools and
assigns them to the DHCP clients. If there is no available IP address in the
interface address pools, the DHCP server picks IP addresses from its global
address pool that contains the interface address pool segment and assigns
them to the DHCP clients.
Trunk: DHCP packets received from DHCP clients are forwarded to an external
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DHCP server, which assigns IP addresses to the DHCP clients.
You can specify the mode to process DHCP packets. For the configuration of the
first two modes, see Chapter 57 "DHCP Server Configuration" on page 593. For
the configuration of the trunk mode, see Chapter 58 "DHCP Relay Agent
Configuration" on page 611.
One interface only corresponds to one mode. In this case, the new configuration
overwrites the previous one.
Protocol specifications related to DHCP include:
RFC2131: Dynamic Host Configuration Protocol
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RFC2132: DHCP Options and BOOTP Vendor Extensions
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RFC1542: Clarifications and Extensions for the Bootstrap Protocol
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