Foundry Networks Switch and Router User Manual

Configuring IP
December 2000 15 - 81
Figure 15.11 DHCP requests in a network with DHCP Assist operating on a FastIron
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 15.12). 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.
Server
Server
DHCP
Server
207.95.7.6
Link
Activity
Link
Activity
Power
Console
FastIron Workgroup
Host 1
200.95.6.x
Host 2
192.95.5.x
Sub-net 1
Host 3 Host 4
Router
202.95.1.x
Sub-net 3
Sub-net 2
Step 1:
DHCP IP address requests
for Hosts 1,2,3 and 4 in
Sub-nets 1, 2, 3 and 4
202.95.5.x
Sub-net 4
192.95.5.1
200.95.6.1
202.95.1.1
202.95.5.1
Step 2:
FastIron stamps each DHCP request
with the gateway address of the
corresponding subnet of the
receiving port.
Gateway addresses:
Step 3:
Router forwards the DHCP request to the
server without touching the gateway
address inserted in the packet by the switch
Interface 2
Interface 8
Interface 14

Foundry Networks Switch and Router Specifications

General

Brand	Foundry Networks
Model	Switch and Router
Category	Switch
Language	English