5548 ARP Timeout/ Switch Mode

Question

Hi, In our production environment we are having intermittent connectivity and slowness across all subnets within our layer 2 network. Everything appears to be find from a hardware stand point. Eventually the issue resolves itself. This has led me to believe that there is something going on with the ARP table and MAC address tables. After doing some research most recommend setting the timeout for both to the same (around 300 seconds). Based on what I found in Dell's PC5548 documentation (Dell PowerConnect 5500 Series CLI Reference Guide) the switch needs to be in switch mode (default is router mode) in order to configure the arp timeout to 300 seconds. Below is an excerpt detailing CLI configuration.  Syntaxarp timeout secondsno arp timeout Parametersseconds—Specifies the time interval (in seconds) during which an entryremains in the ARP cache.(Range: 1–40000000) Default ConfigurationThe default ARP timeout is 60000 seconds in Router mode, and 300 secondsin Switch mode. Command ModeGlobal Configuration mode ExampleThe following example configures the ARP timeout to 12000 seconds.Console(config)# arp timeout 12000 How can I change the 5548 to switch mode? How does changing it to switch mode affect the configurations?  thanks, Leo

DELL-Josh Cr · Answer

Hi, Switch mode is Layer 2 and Router is Layer 3. You should be able to change the ARP setting from the default without disabling routing.

luribe · Answer

Great thanks! Just wanted to confirm before making the change during our nightly maintenance window.

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