Educause Security Discussion mailing list archives

Re: Public Use VLAN (x-posted to netman listserv)


From: Jeff Moore <mail () JEFFMOORE COM>
Date: Wed, 3 Oct 2012 08:15:24 -0700

Interesting. That sounds like a model we originally started with on our
wireless. Initially our wireless was a broadcast ssid that was wide open.
Because of this we treated it as a non trusted network and gave it its own
firewall and external address space(Just enough to do PAT). Also we forced
it to use the smaller of our two links so that if things went south the
rest of our traffic would be unaffected. Also we didnt give it any IPs from
our nets that are associated to our ASNs. So if the link failed the open
network failed(small trade off for isolation. and one that has worked with
the QOS we provided. This is changing). We have changed allot since then
and are working toward full individual client authentication via our new
PaloAlto firewalls.
As for DNS We simply pointed to our external DNS. We have two domains one
internal and one external. With the PIX/ASAs you can use the "dns" flag in
your statics and the firewall will then automatically translate to the
internal IP even though DNS is replying with an external address. But I am
assuming you are setup the other way around with an internal DNS that you
want to pull from. Am I reading this correctly? Not sure if the DNS flag
will work downstream. Would be interesting to see.Maybe that will help.
Sorry for the rudimentary answer.
 One of our perl gurus here has written a nice web page here to get guest
credentials setup for radius. Is that something you all have considered? If
you would like I can put you in touch with him. I am sure he would be more
than happy to share his script. Its version 1.0 and hasn't been deployed
yet but he is really good so I doubt there will be much polishing needed.
Also if you are wanting ammo to push back on open networks use the ol CALEA
ammo! That will stop administration in their tracks! ;)

Good Luck!

Jeff M
CCC

On Tue, Oct 2, 2012 at 6:56 PM, Allen Wood <awood () hillcollege edu> wrote:

 As much as I hate it, I’ve been told to setup an open wireless network
for our campus.  I created a vlan with access lists that deny  all traffic
to inside our network, and created the open SSID to put on it.  Traffic can
flow freely now from the open wireless to the internet.****

** **

However, I’m using a public DNS for the clients and they’re unable to
reach our locally hosted (NAT’d) web servers.  We’re currently using a
Cisco ASA at the edge of our network which does all of our NAT’ing.  I
could open up the VLAN access list a bit and allow them access to our
internal DNS & web servers, but I’d rather not.****

** **

Has anyone run into this issue before?  What’s the “best practices” at
this point… other than removing the public network in the first place!  **
**

** **

Thanks in advance,****

** **

Allen****

** **




-- 
Jeff Moore
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