All: Based on design recommendations from Aruba, our 10,000 AP network has been broken up into a few management domains. For example, Main Campus has approximately 5,000 access points, and the controllers and access points share the same VLAN.
What we have noticed is that if we lose a controller (or shut it down for maintenance or a move), the access points start ARPing like crazy for the downed controller. We can see in excess of 1,000 ARPs a second in the management VLAN. This has the negative side effect of causing CPU spikes across certain models of switches on campus, and we lose management to those switches. User traffic doesn't generally seem affected, but SNMP monitoring ceases. We are wondering if others have seen this, or designed around mitigating this. This is definitely a scaling issue, and we feel as though Aruba could develop back-off mechanisms from allowing High Availability to essentially DoS parts of campus with ARP. Thanks! Ryan Turner Manager of Network Operations ITS Communication Technologies The University of North Carolina at Chapel Hill r...@unc.edu<mailto:r...@unc.edu> +1 919 445 0113 Office +1 919 274 7926 Mobile ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/discuss.
