This article explains why the output is slow when using the command "show arp". It may take up to 30 more seconds to display an address.

When entering the command "show arp", takes a long time for the output to display.

This occurs because the command does a DNS lookup by default to resolve a name for the host IP.

To avoid the DNS lookup, use the command  "show arp no-resolve" or add a DNS server which can be accessed by the device.

 root@> show arp no-resolve
MAC Address Address Interface Flags
3c:94:d5:ba:88:cc 10.10.10.10 ge-0/0/3.0 none

Note: In some cases, we need to check the source address, as it may be taking longer than it should because it is taking a different interface than it should.

We added this for Junos and let this for all platforms.

• show arp