H3C Technologies H3C S3600 Series Switches - Manual (Page 643)

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z When you merge two or more IRF systems into one IRF system, a new master unit is elected, and
the new IRF system adopts new configurations accordingly. This may result in the existing system
configurations (including the address pools configured for the DHCP servers) being lost. As the
new IRF system cannot inherit the original DHCP server configurations, you need to perform
DHCP server configurations for it.
z When an IRF system is split into multiple new IRF systems, some of the new IRF systems may be
degraded to Layer 2 devices. For a new IRF system degraded to Layer 2 device, although the
original DHCP server still exists in the new system, it runs idle for being unable to receive any
packets. When the IRF system restores to a Layer 3 device due to being merged into a new IRF
system, it adopts the configurations on the new IRF system. And you need to perform DHCP server
configurations if the new IRF system does not have DHCP server-related configurations.
z In an IRF system, the UDP HELPER function must be enabled on the DHCP servers that are in
fabric state.
DHCP Server Configuration Task List
Complete the following tasks to configure the DHCP server:
Task Remarks
Enabling DHCP Required
Configuring the Global Address Pool Based
DHCP Server
Configure address
pool based DHCP
server
Configuring the Interface Address Pool Based
DHCP Server
One of the two options is
required
Configuring DHCP Server Security Functions Optional
Configuring DHCP Accounting Functions Optional
Enabling the DHCP Server to Process Option 82 Optional
Enabling DHCP
You need to enable DHCP to make other related configurations take effect.
Follow these steps to enable DHCP:
To do… Use the command… Remarks
Enter system view system-view —
Enable DHCP dhcp enable
Optional
By default, DHCP is enabled.