Brocade TurboIron 24X Series Configuration Guide - Manual (Page 496)

462 Brocade TurboIron 24X Series Configuration Guide
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Configuring IP parameters – Layer 3 Switches
Changing the maximum number of entries the static ARP table can hold
NOTE
The basic procedure for changing the static ARP table size is the same as the procedure for changing
other configurable cache or table sizes. Refer to the section
“Displaying and modifying system
parameter default settings” on page 265
To increase the maximum number of static ARP table entries you can configure on a Layer 3
Switch, enter commands such as the following at the global CONFIG level of the CLI.
TurboIron(config)#system-max ip-static-arp 1000
TurboIron(config)#write memory
TurboIron(config)#end
TurboIron#reload
NOTE
You must save the configuration to the startup-config file and reload the software after changing the
static ARP table size to place the change into effect.
Syntax: system-max ip-static-arp <num>
Configuring forwarding parameters
The following configurable parameters control the forwarding behavior of Layer 3 Switches:
• Time-To-Live (TTL) threshold
• Forwarding of directed broadcasts
• Forwarding of source-routed packets
• Ones-based and zero-based broadcasts
All these parameters are global and thus affect all IP interfaces configured on the Layer 3 Switch.
To configure these parameters, use the procedures in the following sections.
Changing the TTL threshold
The TTL threshold prevents routing loops by specifying the maximum number of router hops an IP
packet originated by the Layer 3 Switch can travel through. Each device capable of forwarding IP
that receives the packet decrements (decreases) the packet TTL by one. If a device receives a
packet with a TTL of 1 and reduces the TTL to zero, the device drops the packet.
The default TTL is 64. You can change the TTL to a value from 1– 255.
To modify the TTL threshold to 25, enter the following commands.
TurboIron(config)#ip ttl 25
Syntax: ip ttl <1-255>
Disabling forwarding of IP source-routed packets
A source-routed packet specifies the exact router path for the packet. The packet specifies the
path by listing the IP addresses of the router interfaces through which the packet must pass on its
way to the destination. The Layer 3 Switch supports both types of IP source routing: