Configuration of cross-network segment DHCP

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Scenario: analog PC with Router and dhcp_server,dhcp_client and dhcp_server are not on the same network segment. Dhcp_client will broadcast Dhcp_discover packet Discovery Dhcp_server, because not the same network segment and the router does not forward the broadcast packet by default, so configure Dhcp_relay to help forward the broadcast packet to Dhcp_server.

Operation Steps:

Step One: Build the experimental environment according to the topology

Step two: Simulate the PC with the router, turn off the routing function and configure the interface to get the IP dynamically

PC (config) #no iprouting// Turn off the routing feature

PC (config) #intf0/0

PC (config-if) #ipaddress DHCP// Configure the interface to obtain IP dynamically

Step Three: Configure the interface address, DHCP address pool, and lease information in Dhcp_server

Dhcp_server (config) #intf1/0

Dhcp_server (config-if) #ipadd 172.16.10.254 255.255.255.0

Dhcp_server (config-if) #nosh

dhcp_server (config) #ipdhcp pool dhcp_pool_1// Configure the address pool name for DHCP

dhcp_server (Dhcp-config) #network192.168.10.0 255.255.255.0// Configuring DHCP address ranges

dhcp_server (dhcp-config) #default-router192.168.10.254// Configure the gateway assigned to the host

dhcp_server (dhcp-config) #lease0 8 0// the rental period is 0 days, 8 hours, 0 minutes .

Dhcp_server (Dhcp-config) #ex

dhcp_server (config) #ipdhcp excluded-address 192.168.10.250 192.168.10.254// in the address pool

Addresses that need to be excluded

dhcp_server (config) #iproute 0.0.0.0 0.0.0.0 f1/0// Configure default Routes

Step four: Configure DHCP Relay

Dhcp_relay (config) #intf0/0

Dhcp_relay (config-if) #ipadd 192.168.10.254 255.255.255.0

Dhcp_relay (config-if) #nosh

Dhcp_relay (config-if) #iphelper-address 172.16.10.254

Dhcp_relay (config) #intf1/0

Dhcp_relay (config-if) #ipadd 172.16.10.1 255.255.255.0

Dhcp_relay (config-if) #nosh

Step five: Observe the process of DHCP relay using Wireshark

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Step Six: View interface address availability

pc#sh IP int b

Interface ip-address OK? Method Status Protocol

fastethernet0/0 192.168.10.1 YES DHCP up up

fastethernet1/0 Unassigned YES unset administratively down

Configuration file

------------------------------------------------------------------------------

Pc#sh Run

!

Hostname PC

!

No IP routing

!

!

......

!

!

interfacefastethernet0/0

IP address DHCP

No IP route-cache

Duplex Auto

Speed auto

!

interfacefastethernet1/0

No IP address

No IP route-cache

Shutdown

Duplex Auto

Speed auto

!

!

......

!

Line con 0

Line aux 0

Line vty 0 4

!

!

End

------------------------------------------------------------------------------

Dhcp_relay#sh Run

Buildingconfiguration ...

currentconfiguration:628 bytes

!

Version 12.4

!

Hostname Dhcp_relay

!

!

!

interfacefastethernet0/0

IP address 192.168.10.254 255.255.255.0

IP helper-address 172.16.10.254

Duplex Auto

Speed auto

!

interfacefastethernet1/0

IP address 172.16.10.1 255.255.255.0

Duplex Auto

Speed auto

!

......

!

Line con 0

Line aux 0

Line vty 0 4

!

!

End

-----------------------------------------------------------------------------

Dhcp_server#sh Run

Buildingconfiguration ...

!

Hostname dhcp_server

!

!

!

IP CEF

No IP dhcp use vrfconnected

IP dhcpexcluded-address 192.168.10.250 192.168.10.254

!

IP DHCP Pooldhcp_pool_1

Network 192.168.10.0 255.255.255.0

Default-router 192.168.10.254

Lease 0 8

!

!

!

interfacefastethernet0/0

No IP address

Shutdown

Duplex Auto

Speed auto

!

interfacefastethernet1/0

IP address 172.16.10.254 255.255.255.0

Duplex Auto

Speed auto

!

!

IP Route 0.0.0.00.0.0.0 fastethernet1/0

!

!

!

Line con 0

Line aux 0

Line vty 0 4

!

!

End

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This article is from "the synthesizer, the United States Tiancheng" blog, please be sure to keep this source http://kidjang.blog.51cto.com/9975340/1769365

Configuration of cross-network segment DHCP