Operations in different situations of DHCP
DHCP server: dynamic host configuration protocol, that is, dynamic host configuration protocol.
Function: ensure that the end host automatically obtains the IP address
The original theory: Cramp S, client / server
Devices are: server, router, switch
1. On the DHCP server, configure the DHCP server IP address and the DHCP address pool for the gateway
two。 Configure the DHCP client (automatically get ip)
Demand:
Make sure that the finance department and outpatient department in the hospital belong to different network segments.
The host of each department automatically obtains the IP address
The network segments are:
Finance Department-192.168.1.0 / 24; 192.168.1.254 (Gateway) 8.8.8.8 (DNS-server)
Outpatient Department-192.168.2.0 / 24; 192.168.2.254 (Gateway) 7.7.7.7 (DNS-server)
Ensure that hosts within and between departments can Ping each other
1. On the DHCP server, configure the DHCP address pool for the gateway
two。 Configure the same gateway address on the corresponding port connected to the router as on the DHCP
Router configuration commands:
Router (config) # interface gi0/0 / / Finance Gateway Interface
Router (config-if) # no shutdown
Router (config-if) # ip address 192.168.1.254 255.255.255.0
Router (config-if) # description GW-CaiWu
Router (config) # interface gi0/0 / / outpatient gateway interface
Router (config-if) # no shutdown
Router (config-if) # ip address 192.168.2.254 255.255.255.0
Router (config-if) # description GW-MenZhen
3. Configure the DHCP client (automatically get ip)
DHCP Relay configuration: (only configured in the gateway port of the outpatient building)
Configuring the router as DHCP relay requires configuration on the gateway port of each department-
Router (config) # interface gi0/1
Router (config-if) # description GW-menzhen
Router (config-if) # ip helper-address 192.168.1.250
/ / the gateway port receives the DHCP discover at this time
After the message, the broadcast message will be unicast.
Send to the DHCP server-192.168.1.250
And the source address is 192.168.2.254
The destination address is 192.168.1.250
Router (config) # service dhcp / / as a DHCP relay, DHCP must be enabled
Note:
When there are multiple DHCP address pools on the DHCP server
The server distinguishes the address pool by the source IP address in the DHCP message.
In a DHCP relay environment, it is essentially based on the gateway IP address of each department
To decide.
On the DHCP server, configure the DHCP address pool for two gateways
At the same time, configure the Gateway IP address on the DHCP server:
Ensure that the DHCP server can respond to DHCP messages sent by DHCP clients of other departments / network segments
