Configurable Arp Retries; Icmp; Configuration Task List For Icmp - Dell Force10 S4810P Configuration Manual

Configurable ARP Retries

In FTOS versions prior to 8.3.1.0, the number of ARP retries is set to 5 and is not configurable. After 5
retries, FTOS backs off for 20 seconds before it sends a new request. Beginning with FTOS version
8.3.1.0, the number of ARP retries is configurable.
The default backoff interval remains at 20 seconds. On the S4810 platform, with FT OS version 8.3.8.0 and
later, the time between ARP resend is configurable. This timer is an exponential backoff timer. Over the
specified period, the time between ARP requests increases. This reduces the potential for the system to
slow down while waiting for a multitude of ARP responses.
Task
Set the number of ARP retries.
Set the an exponential timer for resending unresolved ARPs.
Display all ARP entries learned via gratuitous ARP.

ICMP

For diagnostics, Internet Control Message Protocol (ICMP) provides routing information to end stations by
choosing the best route (ICMP redirect messages) or determining if a router is reachable (ICMP Echo or
Echo Reply). ICMP Error messages inform the router of problems in a particular packet. These messages
are sent only on unicast traffic.

Configuration Task List for ICMP

Use the following steps to configure ICMP:
• Enable ICMP unreachable messages
• Enable ICMP redirects
See the
FTOS Command Line Reference Guide
Enable ICMP unreachable messages
By default, ICMP unreachable messages are disabled. When enabled ICMP unreachable messages are
created and sent out all interfaces. To disable ICMP unreachable messages, use the
command.
Command Syntax
arp retries number
Default: 5
Range: 1-20
arp backoff-time
Default: 30
Range: 1 to 3600
show arp retries
for a complete listing of all commands related to ICMP.
Command Mode
CONFIGURATION
CONFIGURATION
EXEC Privilege
no ip unreachable
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