DHCP Relay over VPN stop working

Question

Hello community, 
 on 3 out of 10 of our sites we've the problem that DCHP Relay over VPN stop working. 
 For testing we've setup a firewall rule on both sites to allow any service. 
 On the first site, where the problem started, one day later it stats working again. 
 At the other two sites it still doesn't work. 
 Has anyone an idea how to solve the problem? 
 
 VPN site A: XG230 (SFOS 17.5.14 MR-14-1) 
 VPN site B: XG105 (SFOS 17.5.14 MR-14-1) 
 
 The DHCP Relay setting on site B. The DHCP server is for all sites the same (Windows Server)

FormerMember · Answer

Hi JanH2019 , 
 Thank you for reaching out to the Community! 
 Did you configure the system route for the firewall originated traffic go through the IPsec VPN tunnel? 
 Check out the following KBA for more info: Sophos XG Firewall: How to Route Sophos Firewall Initiated Traffic Through an IPSec VPN tunnel . 
 Thanks,