Mobile devices can only get to the internet with proxy server setting added

[simon_marshall_]

Hi, we're finding that some mobile devices can't connect to the internet through our wireless network without a proxy server being explicitly configured, whereas others can.

We have a Zone Director 1100 series in our second office.  It’s firmware is as up to date as that model could be. We have a wireless network operating on it with three access points.  All devices can connect via the access points without any problems.

The internet connection used by the Zone Director is in our Cambridge office.  There is a Virgin Media IP/VPN link and a Virgin Media  “National Ethernet” link connecting both offices, the IP/VPN being the main network connection between all of our offices.  

The wireless network uses a specific subnet which we have routed down the National Ethernet link using routes configured on the switches at each office.  IP addresses are assigned from a DHCP scope on a server in our main office.  Our proxy server is in our main office as well.

We are finding that a  Windows PC  can connect to the wireless network and get internet access without a problem, without specific proxy details.  However, if a mobile device tries the same thing, it cannot access the internet.  We’ve found this on a Windows mobile, iPhone and iPad.If I explicitly set the proxy server on the mobile device, it accesses the internet.  The DHCP scope does have a WPAD entry to assign proxy access but it doesn’t appear to be working.  I am  wondering if this is because DNS is routed down the other link (IP/VPN) that connects the offices.

I can’t ping or trace route to the DNS server from a mobile device.
Can anyone help? 

[monnat_systems]

simon,

if i understand from your problem that auto proxy on WLAN working ok for windows machine and does not work for mobiles devices. To get them access at the moment requires you to manually enter proxy details. correct?

problem location is REMOTE and your DNS/DHCP is all at the main office. correct?

do you have same issue with mobile devices at the main office location?
Are WLAN different for Mobile and computer? do IP's from mobile and computers different?
is this something started to happen all of a sudden?

[simon_marshall_]

Hi there,

Yes, a Windows 7 laptop appears to work without adding the proxy details and the mobile devices only work when the proxy server is manually added on them.

The proxy server is in the main office and the location of this wireless network is in a remote office, although it is linked by a Virgin Media IP/VPN with a backup link.

At the main location the problem does not occur.  We have another Zone Director here (it is older) that works fine, all mobile devices can connect to it and access the internet without any manual config.  The overall configuration here is different, at the main office the Zone Director acts as a DHCP server but there is no obvious proxy configured.  As it's on the same overall network in this office (the main office) I think DNS is more easily accessible to the main office Zone Director.

The wireless access in the remote office did used to work and we think that perhaps a change has been made and not recorded that has caused this issue (that we think is with DNS).

The IP addresses supplied to any mobile device on that remote wireless network are the same subnet and are from one range.  A Windows laptop would get an address from the same range as a mobile device would (in this case 10.31.40.xxx)

On the Zone Director in the remote site we have only configured one wireless network.

I hope that helps.

Simon