Configuration Guide User guide

FastIron Configuration Guide 1013
53-1002494-02
Configuring IP parameters – Layer 3 Switches
Brocade(config)# interface ethernet 1/1
Brocade(config-if-1/1)# ip bootp-gateway 109.157.22.26
These commands change the CLI to the configuration level for port 1/1, then change the
BootP/DHCP stamp address for requests received on port 1/1 to 192.157.22.26. The Layer 3
Switch will place this IP address in the Gateway Address field of BootP/DHCP requests that the
Layer 3 Switch receives on port 1/1 and forwards to the BootP/DHCP server.
Syntax: ip bootp-gateway <ip-addr>
Changing the maximum number of hops to a BootP relay server
Each BootP or DHCP request includes a field Hop Count field. The Hop Count field indicates how
many routers the request has passed through. When the Layer 3 Switch receives a BootP/DHCP
request, the Layer 3 Switch looks at the value in the Hop Count field:
• If the hop count value is equal to or less than the maximum hop count the Layer 3 Switch
allows, the Layer 3 Switch increments the hop count by one and forwards the request.
• If the hop count is greater than the maximum hop count the Layer 3 Switch allows, the Layer 3
Switch discards the request.
To change the maximum number of hops the Layer 3 Switch allows for forwarded BootP/DHCP
requests, use either of the following methods.
NOTE
The BootP and DHCP hop count is not the TTL parameter.
To modify the maximum number of BootP/DHCP hops, enter the following command.
Brocade(config)#bootp-relay-max-hops 10
This command allows the Layer 3 Switch to forward BootP/DHCP requests that have passed
through ten previous hops before reaching the Layer 3 Switch. Requests that have traversed 11
hops before reaching the switch are dropped. Since the hop count value initializes at zero, the hop
count value of an ingressing DHCP Request packet is the number of Layer 3 routers that the packet
has already traversed.
Syntax: bootp-relay-max-hops <1 through 15>
DHCP Server
All FastIron devices can be configured to function as DHCP Servers.
NOTE
The DHCP server is platform independent and has no differences in behavior or configuration across
all FastIron platforms (FESX, FSX,FWS, FCX, and ICX).
Dynamic Host Configuration Protocol (DHCP) is a computer networking protocol used by devices
(DHCP clients) to obtain leased (or permanent) IP addresses. DHCP is an extension of the
Bootstrap Protocol (BOOTP). The differences between DHCP and BOOTP are the address allocation
and renewal process.