Installation and Getting Started Guide

DHCP

Server

207.95.7.6

Server

Router

HP Switch 4000

Step 3:

Router forwards the DHCP request to the server without touching the gateway address inserted in the packet by the switch

Step 2:

Gateway addresses:

The HP 6208M-SX stamps each

192.95.5.1

DHCP request with the gateway

200.95.6.1

address of the corresponding

202.95.1.1

sub-net of the receiving port.

202.95.5.1

 

Interface 2

Interface

14

Host 1

 

Host 2

192.95.5.x

 

200.95.6.x

Sub-net 1

Interface 8

Sub-net 2

Hub

Host 3

Host 4

202.95.1.x

202.95.5.x

Sub-net 3

Sub-net 4

Step 1:

DHCP IP address requests for Hosts 1,2,3 and 4 in Sub-nets 1, 2, 3 and 4

Figure 6.11 DHCP requests in a network with DHCP Assist operating on the HP 6208M-SX

When the stamped DHCP discovery packet is then received at the router, it is forwarded to the DHCP server. The DHCP server then extracts the gateway address from each request and assigns an available IP address within the corresponding IP sub-net (Figure 6.12). The IP address is then forwarded back to the workstation that originated the request.

NOTE: The DHCP relay function of the connecting router needs to be turned on.

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