Configuration Guide User guide
1042 FastIron Configuration Guide
53-1002494-02
Configuring IP parameters – Layer 2 Switches
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 subnet (Figure 122). The IP address is then
forwarded back to the workstation that originated the request.
NOTE
When DHCP Assist is enabled on any port, Layer 2 broadcast packets are forwarded by the CPU.
Unknown unicast and multicast packets are still forwarded in hardware, although selective packets
such as IGMP, are sent to the CPU for analysis. When DHCP Assist is not enabled, Layer 2 broadcast
packets are forwarded in hardware.
NOTE
The DHCP relay function of the connecting router must be turned on.
FIGURE 122 DHCP offers are forwarded back toward the requestors
Step 4:
DHCP Server extracts the gateway
address from each packet and
assigns IP addresses for each
host within the appropriate
range.
DHCP response with IP addresses
for Subnets 1, 2, 3 and 4
Step 5:
IP addresses are distributed
to the appropriate hosts.
192.95.5.10
200.95.6.15
202.95.1.35
202.95.5.25
Host 1
Host 2
192.95.5.x
Subnet 1
200.95.6.x
Subnet 2
Host 3
Host 4
202.95.1.x
Subnet 3
202.95.5.x
Subnet 4
Router
DHCP
Server
207.95.7.6
192.95.5.10
200.95.6.15
202.95.1.35
202.95.5.25
Layer 2 Switch
Hub