At Illinois State University, we are an Aruba shop who uses a single
large /17 subnet for our entire wireless network (campus and residence
halls). This allows seamless roaming between our two Aruba controllers
and roughly 3,500 APs. Aruba's "drop unknown broadcast and multicast
traffic" works quite well and and easily accommodates ~20,000 active
clients on a single vlan/subnet. We allow device to device
communication, so clients can screen share and do airplay, as long as
the device doesn't rely on broadcast or multicast to find its peer.
We are in the process of rolling out Aruba's airgroup functionality,
which will allow users to build groups of devices that can broadcast and
multicast to each other. We think airgroup will be mostly used for
consumer devices in the residence halls.
FYI: We did have to implement a firewall rule on the Aruba controller to
block multicast broadcasts from propagating around our campus wired
network. The "drop unknown broadcast and multicast traffic" only applies
between wireless clients. It still allows the multicast broadcats out of
the Aruba controller, where they would overload one of the processors on
the Cisco 6500 SUP 720 distribution switch pair we use for our wireless
L3 gateway.
Network Engineer
Infrastructure, Operations, and Networking
Illinois State University
p: 309-438-4318
On 12/20/2016 6:40 AM, Osborne, Bruce W (Network Operations) wrote:
At Liberty University, we have been using VLAN pools to limit
broadcasts but we are rapidly moving to using larger subnets (up to /16).
Aruba Networks current recommendation is to use large subnets and to
drop unknown broadcast & multicast traffic. We also have a couple of
areas set up tyo Aruba’s LPV (Large Public Venue) recommendations. We
figure if Aruba can handle the Super Bowl at Levi’s Stadium, they know
how to set optimally provide LPV service.
See http://www.arubanetworks.com/solutions/lpv/
*Bruce Osborne*
/Senior Network Engineer/
*Network Operations - Wireless*
*(434) 592-4229*
*LIBERTY UNIVERSITY*
/Training Champions for Christ since 1971/
*From:* Tim Tyler [mailto:[email protected]]
*Sent:* Monday, December 19, 2016 4:46 PM
*Subject:* Re: Large Wireless Deployment Addressing
Chris,
We use vlan pools in our Aruba wireless configurations to
accommodate our students. Normally, the same ip address will follow a
student around as they roam so that makes roaming easier. We have had
problems with large events because we simply don’t have enough AP’s in
some of the large environments that we would need. This means that
in a large event, we over saturate our AP(s). We may address that in
the future, but in the meantime, it is critical for our support staff
to have wireless access at these events. So we created an Event ssid
and provisioned it for an AP that we bring to the event and plug in
before the event. Only our support team is allowed to authenticate to
this particular AP. I know this doesn’t make all of the end users
happy, but it makes our support team happy. Technically speaking,
many devices that connect are automatic and not intentional. So the
majority of people with a cell phone are probably automatically
connecting even though they have no need. But they still saturate.
The bigger problem for us is to deploy more AP’s in those
environments someday.
Tim
*From:* The EDUCAUSE Wireless Issues Constituent Group Listserv
[mailto:[email protected]
<mailto:[email protected]>] *On Behalf Of *Chris
Adams (IT)
*Sent:* Monday, December 19, 2016 1:50 PM
*To:* [email protected]
<mailto:[email protected]>
*Subject:* [WIRELESS-LAN] Large Wireless Deployment Addressing
All,
I wanted to poll the group and see what strategies you are using at
your Universities for client addressing on large wireless networks. We
are revisiting how we address and segment our wireless LAN largely due
to the need to accommodate large events and sports arenas. We have
operated with buildings in various wireless “zones” with a VLAN/subnet
per zone. Going forward some of our larger event spaces will need to
support 3000+ clients in the same building.
What has the approach been for handling address allocations at your
institutions? Most research I’ve found suggests either using VLAN
pooling or very large subnets with client isolation. These won’t
easily work for us, at least in academic areas, as we have many
faculty using airplay, doceri, and other client to client
applications. Going with large subnets per building may cause a lot of
broadcast traffic volume issues and potential roaming issues between
buildings (sticky clients?).
If it helps, we are an Aerohive shop and using Windows Server 2012
DHCP in HA configuration.
Thanks,
**
Chris Adams, CISSP
Director, Network & Telecom Services
Division of Information Technology
University of North Georgia
E-Mail: [email protected] <mailto:[email protected]>| Office:
(706) 867-2891
********** Participation and subscription information for this
EDUCAUSE Constituent Group discussion list can be found at
http://www.educause.edu/groups/.
********** Participation and subscription information for this
EDUCAUSE Constituent Group discussion list can be found at
http://www.educause.edu/groups/.
********** Participation and subscription information for this
EDUCAUSE Constituent Group discussion list can be found at
http://www.educause.edu/groups/.
**********
Participation and subscription information for this EDUCAUSE Constituent Group
discussion list can be found at http://www.educause.edu/groups/.
