Technical data

ServerIron Switching and Routing Guide

Syntax: [no] exclude-ports ethernet <portnum> to <portnum>

Syntax: [no] exclude-ports ethernet <portnum> ethernet <portnum>

These commands specify the ports to which the filter applies.

NOTE: This is the same command syntax as that used for configuring port-based VLANs. Use the first

command for adding a range of ports. Use the second command for adding separate ports (not in a range). You

also can combine the syntax. For example, you can enter exclude-ports ethernet 1/4 ethernet 2/6 to 2/9.

Setting the Broadcast Limit

You can specify the maximum number of broadcast packets the device can forward each second. By default the

device sends broadcasts and all other traffic at wire speed and is limited only by the capacities of the hardware.

However, if other devices in the network cannot handle unlimited broadcast traffic, this command allows you to

relieve those devices by throttling the broadcasts at the device.

The broadcast limit does not affect multicast or unicast traffic. However, you can use the multicast limit and

unknown-unicast limit <limit> global commands to control these types of traffic. The unknown-unicast limit

command specifies the maximum number of unknown-unicast packets the device can forward each second. By

default the device sends unknown unicasts and all other traffic at wire speed and is limited only by the capacities

of the hardware. However, if other devices in the network cannot handle unlimited unknown-unicast traffic, this

command allows you to relieve those devices by throttling the unknown unicasts at the Brocade device.

For example, enter the following command:

ServerIron(config)#broadcast limit 30000

To enable an interface specific configuration, enter commands such as the following:

ServerIron(config)#int e 6

ServerIron(config-if-6)#broadcast limit 30000

Syntax: [no] broadcast limit <num>

Assigning a Gateway List

Dynamic Host Configuration Protocol (DHCP) Assist allows a Brocade switch to assist a router that is performing

multinetting on its interfaces as part of its DHCP relay function. DHCP eliminates the need to manually assign IP

addresses to clients. Instead of each client having a statically configured IP address, clients petition a server for

IP addresses when the clients are booted.

DHCP Assist ensures that a DHCP server that manages multiple IP subnets can readily recognize the requester’s

IP sub-net, even when that server is not on the client’s local LAN segment. The Brocade switch does this by

stamping the correct gateway IP address into a DHCP discovery packet on behalf of the router.

Use the dhcp-gateway-list <num> <ip-addr> command when DHCP Assist is enabled on a Brocade switch. A

gateway address must be defined for each sub-net that will be requesting addresses from a DHCP server. This

allows the stamping process to occur. Each gateway address defined on the switch corresponds to an IP address

of the ServerIron interface or other device involved.

Up to eight addresses can be defined for each gateway list in support of ports that are multi-homed. When

multiple IP addresses are configured for a gateway list, the switch inserts the addresses into the discovery packet

in a round robin fashion.

Up to 32 gateway lists can be defined for each switch.

For example, enter the following command:

ServerIron(config)#dhcp-gateway-list 1 192.95.5.1