Upgrade to 19.5 caused a DNS issue

Question

Hi, 
 I have recently tried to upgrade one of our Sophos XG430 to 19.5 from SFOS 19.0.1 MR-1-Build365 but had to immediately roll it back due to issues. 
 The issues were that we could no longer browse to other network devices via DNS name, we have to use IP addresses. A roll back had to be done & once it was, all was good again. 
 Has anyone else experienced this issue? Is this a known bug? Do I need to adjust any settings before attempting another upgrade? 
 
 Thanks.

Erick Jan · Answer

Hi Jimmy10, 
 Thank you for reaching out to Sophos Community. 
 We don't have reports about your experience updating the Firewall to V19.5. 
 Are you using your Sophos Firewall as the main DNS Resolver for your clients? 
 If you upgrade again, and if the issue remains before rolling back, try checking and doing the following. 
 1. Check DNS configuration and nslookup 
 2. Try to clear the DNS Cache by going to Configure>Network>DNS, then click apply and wait a few seconds until the DNS service restart 
 2. Restart the services if it isn't running 
 3. Check the dnsd.log for any information on the Advanced shell. 
 4. Try to delete and re-configure the DNS settings 
 And adding to this info if you have a ticket open already; if not, open one and add that information.