Losing DHCP Gateway

This problem started with 17.5.0 GA.  The firewall is handling DHCP for my lan.  Users have started to lose the default gateway(the Firewall) randomly throughout the day.  I have to either reset the switch or the desktop network adapter in order to regain internet connectivity.  This does NOT happen to all users at the same time.

I updated to XG 115 SFOS 17.5.5 MR5 but the problem still exists.  This actually introduced another problem of not being able to access the gui from Sophos Central, but that's not as pressing.  Any thoughts on this would be appreciated.



  • In reply to BLS:

    Heck. XG DHCP provides IPs.  That's it that's all.  Absolutely basic.  Will work for "Guest Wireless", but that's the end of it.

    Paul Jr

  • Hi All,

    My sincere apologies for this inconvenience. For any customers who have already upgraded to the latest SFOS release and are still experiencing issues, would it be possible to please raise a support case and PM me with your case ID so that further investigation can be performed?


  • In reply to FloSupport:

    Hi All,

    Thank you for your regress feedback & support

    With MR6, we have been closed with JIRA ID NC-46351, which was earlier reported. 

    We are working on the JIRA ID NC-48031, till now please use the CLI to switch the DHCP old config generate method.







  • Have been having this same issue, have upgraded my firmware to 17.5 6 and have not seen the difference.

    Aside, resetting the LAN card, is there any solution by Sophos yet?

  • In reply to Oluseye Arinde:

    run the following from Console,


    console> system dhcp conf-generation-method old


  • I'm still experiencing this one. I've already change back to the old method and restarted the device. Anyone can help me on this?


  • In reply to NoWords:



    you need to rollback to 17.5 MR5, and dont change the old method.



  • In reply to Parham Pourkhosravy:



    So if I roll it back do i need to change the method again?

    Sorry for asking I'm still new to Sophos XG and my manager doesn't want me to roll back without other information.

  • In reply to NoWords:

    It should set to old and you don't need to change it again, but you can check it from console instead or set in the beginning use show and remove the old.

  • In reply to Parham Pourkhosravy:

    I'll try this later. Thank you.

  • In reply to Parham Pourkhosravy:

    Thank you for  your response, Please how do i revert back to 17.5 as the earliest version on my dashboard is 17.5.5 MR -5

    is there a way to download firmware and directly upload to XG ? Share link Please

    Thanks again.

  • In reply to Oluseye Arinde:

    Do we have an update to this issue yet ?

  • In reply to deeptibhavsar:



    for me the cli command did not helped - the DHCP actually gives me default gateway and DNS IP adressses for the wireless clients, but still no internet connection available for them. All of the wireless clients are affected. (TV, laptops, wifi extenders, etc)


    I also noticed that on the interface tab my default gateway which is facing towards the internet is showing status a big red dot. 


    The wired or virtual Network clients are able to use he connection without any issue and connecting to the internet.


    It started to happen only today. The upgrade was done to MR6 a week ago aproximatelly.


    The firewall is running on Hyper-V. Rebuilding the DHCP did not helped.


    I have another XG home on phyical machine which was upgreded same time and have same configurtaion, but that did not experience this issue.


    Any ideas what I can do?


    red color: guest WLAN

    Green color: LAN/WLAN intranet

    blue color: internet

  • In reply to Tibor Soós:

    Actually i rebuilded the XG Firewall on Intel hardware (and finished with the Hyper-V one) with the latest firmware and its working without any issue.