DHCP option 82 Configuration
288
option domain-name "example.com.cn";
option domain-name-servers 192.168.10.3;
authoritative;
pool {
range 192.168.102.21 192.168.102.50;
default-lease-time 86400; #24 Hours
max-lease-time 172800; #48 Hours
allow members of "Switch3Vlan2Class1";
}
pool {
range 192.168.102.51 192.168.102.80;
default-lease-time 43200; #12 Hours
max-lease-time 86400; #24 Hours
allow members of "Switch3Vlan2Class2";
}
}
Now, the DHCP server will allocate addresses for the network nodes from Switch1
which are relayed by Switch3 within the range of 192.168.102.21 ~ 192.168.102.50, and
allocate addresses for the network nodes from Switch1 within the range of
192.168.102.51
～
192.168.102.80.
33.4
DHCP option 82 Troubleshooting
DHCP option 82 is implemented as a sub-function module of DHCP Relay Agent.
Before using it, users should make sure that the DHCP Relay Agent is configured
correctly.
DHCP option 82 needs the DHCP Relay Agent and the DHCP server cooperate to
finish the task of allocating IP addresses. The DHCP server should set allocating
policy correctly depending on the network topology of the DHCP Relay Agent, or, even
the Relay Agent can operate normally, the allocation of addresses will fail. When there
is more than one kind of Relay Agent, please pay attention to the retransmitting policy
of the interface DHCP request messages.
To implement the option 82 function of DHCP Relay Agent, the ―debug dhcp relay
packet‖ command can be used during the operating procedure, including adding the
contents of option 82, the retransmitting policy adopted, the option 82 contents of the
server peeled by the Relay Agent and etc., such information can help users to do