This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

Question for excepting certain destination on the web filtering

Hello, 

 

i want to configure a excepting  a certain destination on the web filter. but i can't complete this configuration. 

(Web filtering is in transparent. )


So i tried to add the destination url on the "Skip transparent mode destination host/nets" following KB 120839.

community.sophos.com/.../120839

 

but exception is not working well. 

 

For example, i want to except the google.com on the web filtering. 

So i add the www.google.com to the "Skip transparent mode destination host/nets". 

but when i access the google.com, http.log is generated regarding google.com. (action="pass")


It would be much appreciated, if anyone helps me to configure an exception on web filter.



This thread was automatically locked due to age.
Parents
  • Hi,

    do you have a firewall rule that will allow this site to be accessed?

    I suspect you need to add something like this *.google.com.*

     

    XG115W - v20.0.2 MR-2 - Home

    XG on VM 8 - v21 GA

    If a post solves your question please use the 'Verify Answer' button.

  • Hi, 

     

    www.google.com is just example for explaining. 

    When i tested i tried to access www.npr.org. 

    and i added a reject firewall rule for www.npr.org for blocking at the level of firewall. 

     

    Thanks, 

  • You might want to reading my UTM architecture post in the Wiki section of this forum.  Short version:

    When you bypass web filtering, the traffic is instead evaluated by the firewall rules, which is why the other reply said to ensure that the firewall allows traffic through it.

    Other notes:

    Many websites invoke content from other (seemingly unrelated) URLs.  So if your site does not load properly, you may need to check web filtering logs for dependent content blocks.

    Your other option is to configure a webfilter exception which turns off specific rules without disabling webfiltering completely.

    Note that www.example.com is not the same as example.com.   In the transparent host skiplist, you should specify example.com and www.example.com as DNS hosts for an exact match on host name.  If you want to exempt *.example.com, I think you need to specify a DNS group for example.com

  • Hello Degulas, 

    Thanks for your help. 

     

    I agree that what the most of main URL contains many other URLs to call the web page.

    So I expected that some of contents were not displayed because of above reason.

    But all contents were displayed when I accessed the www.npr.org.

     

    Anyway...

    I tried to test again with another simple web site (www.globaltelecom.co.kr)

    It worked well when I added the url to the skip list.

    (it was not generated the log in the http.log)

     

    However, it is not blocked by the firewall rule after adding a firewall rule based on URL(DNS Group).

    (Ultimately, I want to block certain IP ranges that contain web page using firewall rule.

    This is a reason why i want to bypass for certain web page.)

    And i can't see any relevant logs in the packetfilter.log.

     

    When I turn off the web protection, i can see relevant logs in the packetfilter.log.

    Because that traffics were controlled by the firewall rule.

     

    As my result, If certain destination is bypassed on the web filtering, it will bypass firewall rule also.

     

    Is it correct result?

    Or do i have something wrong?

     

    Thanks

Reply
  • Hello Degulas, 

    Thanks for your help. 

     

    I agree that what the most of main URL contains many other URLs to call the web page.

    So I expected that some of contents were not displayed because of above reason.

    But all contents were displayed when I accessed the www.npr.org.

     

    Anyway...

    I tried to test again with another simple web site (www.globaltelecom.co.kr)

    It worked well when I added the url to the skip list.

    (it was not generated the log in the http.log)

     

    However, it is not blocked by the firewall rule after adding a firewall rule based on URL(DNS Group).

    (Ultimately, I want to block certain IP ranges that contain web page using firewall rule.

    This is a reason why i want to bypass for certain web page.)

    And i can't see any relevant logs in the packetfilter.log.

     

    When I turn off the web protection, i can see relevant logs in the packetfilter.log.

    Because that traffics were controlled by the firewall rule.

     

    As my result, If certain destination is bypassed on the web filtering, it will bypass firewall rule also.

     

    Is it correct result?

    Or do i have something wrong?

     

    Thanks

Children
  • Please show a Web Filtering log line with a block of something you want or a pass of something you wanted to block.

    Cheers - Bob

     
    Sophos UTM Community Moderator
    Sophos Certified Architect - UTM
    Sophos Certified Engineer - XG
    Gold Solution Partner since 2005
    MediaSoft, Inc. USA
  • Hello Bob, 

    Any log were not generated after bypass for certain destination at the web filtering.

    what i want to know is whether the certain destination is possible to block or not on the level of firewall after bypass the certain destination at the web filtering.

  • Yujin, If I understand what you are trying to ask, you are using the product in a very nonstandard way.

    It may be better if you describe your ultimate goal, and we can tell you how to meet that goal.

    Right now you've already decided on a solution and are asking for help in that solution but we're having trouble understanding what you are doing.

     

    Note:  The transparent mode skip is in the Web section, however strictly speaking it is not a Web rule, it is a firewall rule.

    When you configure the Web "Allowed networks" what you are really doing is creating a firewall rule that says "anything coming in on port 80 from this network going out to the internet, forward the packets to the Web Proxy".  When you create a destination skiplist what you are really doing is creating a firewall rule above that saying "anything going to port 80 to these IP addresses, do not forward the packet to the Web Proxy".  The skiplist must work on IPs (to UTM objects that resolve to one of more IPs).

  • Hello All,

    Ultimately, my goal is that adding a firewall rule to block certain destination including web server at the level of firewall when web filtering is enabled.

    == Scenario for my goal ==

    • Issue: 1.1.1.10 is a web server. If I add a firewall reject rule for destination 1.1.1.0/24 , it is impossible to block 1.1.1.10 at the level of firewall because 1.1.1.10 is a web server.
    • Goal: block for 1.1.1.0/24 at the level of firewall including web server
    • SG firewall configuration: enable for firewall and web filtering.
    • Expectation
      Adding a 1.1.1.0/24 to the transparent skiplist at web filter.
      I expected that if 1.1.1.0/24 is bypassed at the level of web filter, it might be possible to block for all 1.1.1.0/24 including 1.1.1.10 at the level of firewall.
    • Result
      Clients behind the SG firewall can access the 1.1.1.10 even though it has a firewall reject rule for 1.1.1.0/24. Because web filter is enabled.
      That means web traffic is proxied.

    I found a helpful article and then i could understand why i can't achieve my goal.
    https://community.sophos.com/kb/en-us/115155 - Create A Basic Firewall (Packet Filter) Rule in Astaro Security Gateway

    KB115155 explains the Proxied Services.
    Based on the explanation of Proxied Service, it is impossible to control(allow or deny) web traffic at the level of firewall when web proxy is enabled.

    Maybe, I tried to use nonstandard way like the Michael's mention.

    Thank you very much for all for help me.

  • You must uncheck 'Allow HTTP/S traffic for listed hosts/nets' underneath the Skiplists and make your own firewall rules for each of the listed destinations.

    Cheers - Bob

     
    Sophos UTM Community Moderator
    Sophos Certified Architect - UTM
    Sophos Certified Engineer - XG
    Gold Solution Partner since 2005
    MediaSoft, Inc. USA
  • Hello Bob,

    I thinks it is impossible to control(allow or deny) for web traffic using firewall when web filter is enabled even though if i uncheck ''Allow HTTP/S traffic for listed hosts/nets' underneath the Skiplists. Because web traffic is proxied when web filter is enabled.

    Please refer the KB115155.
    This KB article that explained the Proxied server would be helpful for understanding.

    Thanks,

  • You've misunderstood how the UTM works.  In Transparent mode, the Transparent mode Skiplists prevent the UTM from proxying the traffic.  If you have configured your browser to use the UTM's Web Filtering, you must configure the browser to skip the proxy as the Transparent mode Skiplists do not apply.

    If you're still not able to get firewall rules to allow or block HTTP & HTTPS, paste a line here from the Web Filtering log file for an access that you wanted to skip the Proxy and show a picture of your Skiplists.

    Cheers - Bob

     
    Sophos UTM Community Moderator
    Sophos Certified Architect - UTM
    Sophos Certified Engineer - XG
    Gold Solution Partner since 2005
    MediaSoft, Inc. USA
  • It is possible that i have misunderstanding about how the SG work because I just have an experience under 6 months about SG.
    But based on my test result, it looks like impossible to control(allow or deny) using firewall rule even though i add a destination in the transparent mode skiplist.

    I added the DNS host that i want to bypass at the web filter in the Transparent mode skiplist like below.
    (My test SG is in Transparent mode and Web filter is in full transparent mode. So i don't need to consider the web browser setting for proxy.)

    Web filter log(http.log) and firewall log(packetfilter.log) were not generated when i tried to access the destination. but i could access the destination even though i added a firewall reject rule against destination.

    Below is my firewall reject rule about destination that i want to block at the firewall level.


    could you explain me why my test result is different from your thinking?

  • I am guessing that your problem occurs because npr.org and www.npr.org are different host names.  Your approach should work, but it is unneccessaily complicated.

    You can get the result more easily by using the Websites tab of your Filter. It takes host names or regular ecpressions.   It allows both nlock and allow overrides.

  • i didn't have a test with www.npr.org

    when i tested i only used www.globaltelecom.co.kr.
    it is very simple website. because this website doesn't contain any other url.