IdentiFi (formerly Enterasys, HiPath) Wireless Controller; models C20, C25, C4110, C5110, C5210, V2110; firmware 8.21.04.0023, 8.21.05.0005
Enterasys thin Access Point (AP); models AP3705, AP3710, possibly others
A mobile user (MU) has connected to a managed Access Point.
The user receives an IP address, but cannot IP communicate (e.g. PING) to any other device for 18-20 seconds after the initial connection, thus cannot immediately establish any IP-based network contact.
The AP is not sending out ARP packets correctly, so the user's outgoing ARP requests are being dropped by recipients.
Upgrade to firmware 8.21.06.0006 or higher.
Release notes state, in the 'Changes in 8.21.06.0006' section:
Corrected a timing issue on AP37xx that resulted in longer ARP resolution time on some clients
Pre-upgrade workaround: If the VNS service is using 802.1X authentication, disable the rekeying for the authentication.