Hi: In one of our sites we hot-swapped a SonicWALL TZ for a brand new shiny MX84.  The site has a Windows Domain Controller with DHCP, all laptops are domain attached, and there is a number of iPads/iPhones.  They mostly connected over site-to-site VPN to the HQ to access an IIS based application.     After staging the MX at a testing area, the guys set it beside the TZ and once it booted, live moved the cables from old device to new.   All seemed well. Tunnel established with the MX250 at HQ (in VPN concentrator mode) and my laptop connected back over VPN and also out the local Internet fine. All working perfect - latency etc. just as expected.   However - many of the local laptops and all the iPads and printers needed a change of IP address to be able to access anything.  Some clients could ping everything back at HQ - EXCEPT the IIS server; and so were not able to access the application. Changing the IP address (same subset, just a previously unused address) seemed to fix it (mostly)   Now - for my next site we don't have enough free scope in DHCP to change ALL the addresses - its a much bigger operation.   Looking for a good process to switch over from TZ to MX without having to change every IP address!!   Thx ... View more