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WS1000 - site blocked but allowed

Hi,

 

My organisation is running a WS1000. A user is having trouble with Microsoft Office 365. A "Recent Activity Search" by user shows that the site https://organisationName.nhs.uk is Blocked.

A Group Policy Local Site List check for that site & that user say it is allowed, it's tagged "Globally allowed sites".

 

Is there any way to get more information and see what the problem really is?

 

Thanks,

 

Ed



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  • If you go to that website yourself do you also get blocked?

     

    HTTPS site, it could be SSL/certificate.

  • There is no website to visit, MS Outlook is looking for the autodiscover.organistatonName.nhs.uk URL - which is also allowed and reports correctly.

  • auto discovery look ups should not go through the appliance. 

    ideally you should.

    A: make a firewall rule to send the request directly to your auto discovery address.

    or

    B: make a dns entry for your auto-discovery address and resolve it to 127.0.0.1 .. this will cause outlook to fail and search locally for the users mailbox.

  • You either have to add "nhs.uk" or "autodiscover.organisationName.nhs.uk" to Local Site List.

    This is the way how whitelisting with the Sophos web appliances works. You either have to add the whole domain or the full qualified host name.

    Subdomains don't work. This is my experience.

     

    Regards,

    Holger

  • this is correct. the appliance assumes any wild card domains.

     

    however,

     

    the web appliance is a proxy and it is designed to work with one of the 4 supported browsers.  http://swa.sophos.com/webhelp/swa/concepts/IntroPlatformsAndUserInterface.html?hl=browser

     

    Auto discovery is making requests that emulate browser request, but autodiscovery is a service ie: https://technet.microsoft.com/en-us/library/bb124251(v=exchg.160).aspx

     

    so yes.. you can "make" it work, however it is not recommended, or supported .. the best solution is not to send these requests through the appliance.

  • Hi Red_Warrior,
    This is both correct and not.  The SWA (as well as the other web proxies we have in the UTM and XG) can handle HTTP/HTTPS traffic that comes from non-web browsers just fine.  A significant amount of HTTP/HTTPS traffic does not come from web browsers.  However some of those applications do not behave correctly when they encounter a proxy.  That is really a fault of the application and not the proxy, but we as a makers of the proxy need to be able to handle it.  Which we do.
     
    The problems of autodiscover over UTM and XG are well know.  I don't recall any problems with autodiscover in SWA, I think usually it just works.
     

    Hi Ed Morgan,
     
    The way outlook autodiscover works is that it tries several different mechanisms in a row to find the server, because for example it does not know if the laptop is currently on your LAN or connecting remotely.  Some of the mechnisms fail and that is perfectly normal and expected.
     
    Do you actually have a problems with outlook, or are you just tracking down a blocked message?
     
    Are there any other details you can share?
  • Hi, We were having a problem with Outlook; it was coming up with a proxy authentication request box which would not go away even when the correct credentials were used. Outlook would not open some user's calendar & would not open shared mailboxes. The blocked message appeared in the WS1000 logs at the same time.

    We have added the site to proxy bypass in Internet Explorer and that solves the problems, but it's not ideal. Some satellite sites do not have internet access except via the proxy.

     

    Thanks,

     

    Ed

  • Hi Ed,

    As I mentioned before the best and recommend solution is to omit the traffic. 

    as a full explication is not thread friendly .. the autodiscover client expects essentially a yes/no response.  when you start adding things like SSH certs, other internet codes, like a 307 or similar.. authentication and all of the "other" things in a typical network.   It becomes a major pita. 

    the other issue is, its a "service" so if ms changes anything anyone of these "fixes" may or may not be affected.  As I mentioned I strongly suggest omitting the traffic. \

     

    that been said here are the ways you can "make" it work

    #1 ensure the workstation has the appliances ssl certificate installed (any ssl error will cause issues) its a client, it cant hit yes to accept a self signed cert. so it must be pushed out as per https scanning.

    #2 under authentication profiles.. 

    step 1: create a profile based on IP ranges, enter in your ip ranges ie: 10.0.0.0/8

    step 2: under authentication tab.. create a new bypass profile, under sites.. enter your autodiscover.mydomain.com  check off.. bypass authentication. 

    #3 you could create a local site list entry for autodiscover.mydomain.com set it as globally allowed.. (or change the category to custom) and allow specific groups / users to access the custom category.

    #4 black hole the dns request as mentioned before, causing the request to fail.. the autodiscover client will time out properly and default to the network look up

    #5 In your case if you have a mixed onsite/off site environment, configured via proxy.. consider creating / hosting a proxy .pac file. something like this..

     

    function FindProxyForURL(url, host)
    {
    // variable strings to return
    var proxy_yes = "PROXY 192.168.1.1:8080";
    var proxy_no = "DIRECT";

    if (shExpMatch(url, "www.mycompanywebsite.com*")) { return proxy_no; }
    if (shExpMatch(url, "www.myotherwebsite.com*")) { return proxy_no; }
    if (shExpMatch(url, "www.my3rdlocalsite.com*")) { return proxy_no; }
    if (shExpMatch(url, "http://192.168.1.100*")) { return proxy_no; }
    // Proxy if PC is on local LAN
    if (isInNet(myIpAddress(), "192.168.1.0", "255.255.255.0"))
    return "PROXY 192.168.1.1:8080";
    else
    return "DIRECT";
    }

     

     

    replace one of the entries with your autodiscover address so that any request is sent "direct" .. host it and push it out 

     

    The recommended solution is bypassing the appliance altogether.. In your case as you mentioned using a mixed proxy environment.. the BEST solution is #5 the proxy .pac file.  It solves not only this issue, but gives your the ability to correct any other proxy issues and or specifically tailor an internal or external workstation, machine or other infrastructure. 

     

    The SWA is a true proxy.. it will always return an answer for every request it makes (unlike a UTM/xg that contains a firewall ie: a response could be dropped hence causing the service to fail normally). .. when ever a response (like a ssl cert, or authentication or any other response is returned to the auto discover service.. the service its self does not understand what to do.  This is the same with things like fax machines, photocopiers and another infrastructure that will fail closed.

     

    This is why I highly recommend omitting the proxy from this service.  Yes you "can" make it work.. but its not recommended..  the only traffic that should ever go through a swa is:

    #1 traffic that requires policy and or authentication for users to prevent unauthorized internet use and police/track sites.

    #2 Only traffic sent via one of the 4 approved browsers. (no pdf/stamp/photocopiers.. or services/applications)  

    All internal requests should be explicitly omitted. (something like this is generally apart of your .pac file)

    if (isInNet(dnsResolve(host), "192.168.0.0/16", "255.255.0.0"))
    return "DIRECT";

    etc

     

    Unfortunately support cant write a .pac file for you, but here are the resources I use, if your really stuck we do offer professional services, just get in touch with your account manager.

    findproxyforurl.com/.../
    community.sophos.com/.../38784
    community.sophos.com/.../38787
    community.sophos.com/.../38783
    community.sophos.com/.../38788