ii
IP address lease extension···································································································································· 26
DHCP message format ··················································································································································· 27
DHCP options ································································································································································· 28
DHCP options overview ········································································································································ 28
Introduction to DHCP options ······························································································································· 28
Self-defined options ··············································································································································· 29
Protocols and standards ················································································································································ 32
Configuring the DHCP server ···································································································································· 34
Overview ········································································································································································· 34
Application environment ······································································································································· 34
DHCP address pool ··············································································································································· 34
IP address allocation sequence ···························································································································· 35
DHCP server configuration task list ······························································································································ 36
Configuring an address pool for the DHCP server ····································································································· 36
Configuration task list ··········································································································································· 36
Creating a DHCP address pool ··························································································································· 37
Configuring address allocation mode for a common address pool ································································ 37
Configuring dynamic address allocation for an extended address pool ························································ 39
Configuring a domain name suffix for the client ······························································································· 40
Configuring DNS servers for the client ··············································································································· 40
Configuring WINS servers and NetBIOS node type for the client ·································································· 41
Configuring BIMS server information for the client ···························································································· 41
Configuring gateways for the client ···················································································································· 42
Configuring Option 184 parameters for the client with voice service ···························································· 42
Configuring the TFTP server and bootfile name for the client ··········································································· 43
Specifying a server's IP address for the DHCP client ························································································ 43
Configuring self-defined DHCP options ·············································································································· 44
Enabling DHCP ······························································································································································ 45
Enabling the DHCP server on an interface ·················································································································· 45
Applying an extended address pool on an interface ································································································ 45
Configuring the DHCP server security functions ········································································································· 46
Configuration prerequisites ·································································································································· 46
Enabling unauthorized DHCP server detection ·································································································· 46
Configuring IP address conflict detection ··········································································································· 46
Configuring the DHCP server to support authorized ARP ················································································· 47
Enabling client offline detection ··································································································································· 48
Enabling Option 82 handling ······································································································································ 48
Configuration prerequisites ·································································································································· 48
Enabling Option 82 handling ······························································································································ 49
Specifying the threshold for sending trap messages ·································································································· 49
Configuration prerequisites ·································································································································· 49
Configuration procedure ······································································································································ 49
Displaying and maintaining the DHCP server ············································································································ 49
DHCP server configuration examples ·························································································································· 50
Static IP address assignment configuration example························································································· 51
Dynamic IP address assignment configuration example ··················································································· 52
Self-defined option configuration example ········································································································· 53
Troubleshooting DHCP server configuration ··············································································································· 54
Symptom ································································································································································· 54
Analysis ·································································································································································· 54
Solution ··································································································································································· 55
Configuring the DHCP relay agent ··························································································································· 56
Introduction to DHCP relay agent ································································································································ 56
