Users Guide

The relay agent strips Option 82 from DHCP responses before forwarding them to the client.
To insert Option 82 into DHCP packets, follow this step.
• Insert Option 82 into DHCP packets.
CONFIGURATION mode
int ma 0/0
ip add dhcp relay information-option remote-id
For routers between the relay agent and the DHCP server, enter the trust-downstream option.
Releasing and Renewing DHCP-based IP Addresses
On an Aggregator configured as a DHCP client, you can release a dynamically-assigned IP address
without removing the DHCP client operation on the interface.
To manually acquire a new IP address from the DHCP server, use the following command.
• Release a dynamically-acquired IP address while retaining the DHCP client configuration on the
interface.
EXEC Privilege mode
release dhcp interface type slot/port
• Acquire a new IP address with renewed lease time from a DHCP server.
EXEC Privilege mode
renew dhcp interface type slot/port
Viewing DHCP Statistics and Lease Information
To display DHCP client information, enter the following show commands:
• Display statistics about DHCP client interfaces.
EXEC Privilege
show ip dhcp client statistics interface type slot/port
• Clear DHCP client statistics on a specified or on all interfaces.
EXEC Privilege
clear ip dhcp client statistics {all | interface type slot/port}
• Display lease information about the dynamic IP address currently assigned to a DHCP client interface.
EXEC Privilege
show ip dhcp lease [interface type slot/port]
View the statistics about DHCP client interfaces with the show ip dhcp client statistics command and the
lease information about the dynamic IP address currently assigned to a DHCP client interface with the
show ip dhcp lease command.
Dynamic Host Configuration Protocol (DHCP)
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