Dell C1048P Port Extender Networking Configuration Guide for the C9000 Series - Page 467

arp retries number The default is 5. The range is from 1 to 20. • Set the exponential timer for resending unresolved ARPs. CONFIGURATION mode arp backoff-time The default is 30. The range is from 1 to 3600. For information about the arp backoff-time command, see Configuring the Timer for Resending Unresolved ARPs. • Display all ARP entries learned via gratuitous ARP. EXEC Privilege mode show arp retries ICMP For diagnostics, the 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 Tasks for ICMP The following lists the configuration tasks for ICMP. • Enabling ICMP Unreachable Messages For a complete listing of all commands related to ICMP, refer to the Dell Networking OS Command Line Reference Guide. Enabling ICMP Unreachable Messages By default, ICMP unreachable messages are disabled. When enabled, ICMP unreachable messages are created and sent out all interfaces. To disable and re-enable ICMP unreachable messages, use the following commands. • To disable ICMP unreachable messages. INTERFACE mode no ip unreachable • Set the system to create and send ICMP unreachable messages on the interface. INTERFACE mode ip unreachable To view if ICMP unreachable messages are sent on the interface, use the show config command in INTERFACE mode. If it is not listed in the show config command output, it is enabled. Only non-default information is displayed in the show config command output. IPv4 Routing 467