Odd Proxy Problem - (El Capitan)

[jtotheb]

I've got a peculiar problem

 

Fresh El Capitan install.

 

Mac is domain joined.

 

Login with AD credentials works fine.

 

HTTP and HTTPS proxy are configured via FQDN and the correct port.

 

Kerberos is configured for the Sophos UTM which is acting as a proxy. (SPNs can be seen in AD)

 

Running klist on the mac displays the UTM ticket.

 

No HTTP proxy prompt happens and can surf happily.

 

HTTPS proxy prompt does pop up

 

Ideas and/or eduhobnobs welcome.

 

(I should add this is the first time it's been tried. Our old Macs have the proxy settings set by IP address and prompt 24/7 which was kind of expected)

Edited April 13, 2016 by jtotheb