On Sat, 6 Apr 2013, Frank Bulk wrote:
If you're using consumer APs then you're not going to have smooth handoffs
to APs, so user sessions will be interrupted as the client dis-associates to
the old AP, associates to the new, acquires an IP address, and then
re-establishes the VPN. That's not smooth.
Ahh, but if they keep the same SSID, and the APs are bridged with DHCP being
handled at some central server (not on the individual APs, then moving from one
AP to another is just dis-associating andassociating to the new one. No need to
change IP addresses, no need to re-establish the VPN.
It may be
In regards to volumes, there are many larger deployments that are moving
several hundred megabits per second -- how much do you really want to pay
for a redundantly-configured VPN with that kind of traffic load?
Well, it depends on what VPN you choose to use. With some VPNs you can either
use commodity servers as the endpoints, or put in encryption cards that can do
this reasonably cheaply
on the same basis, how much are you willing to spend on your wireless system to
avoid having a high capacity VPN system? :-) Having seen a company spend $50K on
a system of about a dozen APs in one building (before it got scrapped to go with
an even more expensive system) when I would be comfortable spending around $5K
to provide service to the same building, the amount of money here is fairly
significant.
My expectation is that anyone who is doing things on that scale probably has
large pipes to the Internet and needs a high capacity VPN setup to support the
users when they are remote outside the campus
Google "Wi-Fi machine authentication" to see some articles that talk about
how devices joined to the domain can be on the wireless network without
having the end-user logged in.
Thanks for the pointer. You still have the problem that they machines may be
powered off, or otherwise unreachable, so I somewhat question the value of this
in practice.
by the way, most of the links I'm finding on the first few pages of google seem
to be for people who want _only_ machine authentication for network traffic.
David Lang
Frank
-----Original Message-----
From: David Lang [mailto:[email protected]]
Sent: Saturday, April 06, 2013 6:51 PM
To: Frank Bulk
Cc: [email protected]
Subject: RE: [lopsa-tech] Wifi
why does the movement of users matter much? Users can roam between different
APs
with the same SSID with a VPN just fine.
Also, why do you say 'low traffic volumes'? if you are encrypting the data,
it's
going to cost to encrypt it even if you do it at the wifi level instead of
the
VPN level.
you can configure VPNs so that they are connected all the time as well, but
any
plan to push things down or run scheduled tasks from a central point to
portable
devices needs to deal with the idea that the devices may not have
connectivity
(they may not even be turned on)
always-connected and authenticated don't work well together, so how do you
have
Radius authenticated Wifi and still have systems connected without the user
being logged in?
David Lang
On Sat, 6 Apr 2013, Frank Bulk wrote:
In an environment when the Wi-Fi clients don't move around much, the Wi-Fi
clients are all devices with VPN-capable, and traffic volumes are low,
VPNs
may work, but in most organizations, and especially higher-ed, WPA2 with
AES
based on RADIUS authentication is the BCP. Most organizations want
machine-authentication, so that even while the end-user is not logged in
policies can be applied and pushed down, scheduled tasks can run, etc.
Frank
-----Original Message-----
From: David Lang [mailto:[email protected]]
Sent: Saturday, April 06, 2013 2:56 PM
To: Frank Bulk
Cc: [email protected]
Subject: RE: [lopsa-tech] Wifi
On Sat, 6 Apr 2013, Frank Bulk wrote:
Hmm, I want to access my organization's resources over Wi-Fi -- why treat
it
as untrusted? The security with WPA2 using AES is more than sufficient.
That same statement was made about WEP and WPA. It may be true, it may not
be
true (they don't have a good track record here). It may depend on the
attacker
never having been able to extract data from a laptop of someone who has
been
authorized to use the network (is WPA2 really secure if an attacker has
been
able to read keys off of someone's machine?)
Your users need to be using VPN software anyway when working from other
networks, so adding WPA and it's management is additional work that you
don't
have to do.
It's a lot easier to change your VPN software if needed
VPN software gives you additional tools for authentication of your users
(things
like hardware tokens for example)
In short, I see VPNs as something you are doing anyway, are more flexible,
and more trustworthy.
David Lang
Frank
-----Original Message-----
From: [email protected] [mailto:[email protected]]
On
Behalf Of David Lang
Sent: Saturday, April 06, 2013 12:34 AM
To: Brian Gold
Cc: [email protected]
Subject: Re: [lopsa-tech] Wifi
On Fri, 5 Apr 2013, Brian Gold wrote:
We've been using Cisco WCS controllers and APs here at $employer, but
for
a
smaller scale I've been very happy with Ubiquity APs and controllers. I
would HIGHLY recommend setting up radius authentication if you have
a centralized ldap system (Active Directory, OpenLDAP, etc).
I would actually go the opposite direction.
Your Wifi is an untrusted network that can be sniffed and attacked by
anyone
in
the area. So don't let it connect directly to your internal network.
Consider it a guest network, just like a hotel network, and have all your
users
connect to your company resources through a VPN, just like they would
from
home
or a hotel.
Then you can consider if you want to have the network locked down so that
it
can
only be used for VPN traffic, or if you really do want it to be a guest
network,
able to reach the Intenet (for at least some things)
David Lang
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