# Downward compatibility **URL:** \ **Category:** Forum\ **Tags:** Adabas-Natural, Natural, Natural-Single-Point-of-Development-SPoD, Natural-on-Windows-Unix\ **Created:** [April 11, 2008, 6:14am UTC](https://techcommunity.softwareag.com/t/downward-compatibility/76536 "2008-04-11T06:14:34Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![Ralph\_Zbrog](https://sea1.discourse-cdn.com/techcommunity/user_avatar/techcommunity.softwareag.com/ralph_zbrog/32/78_2.png) [@Ralph\_Zbrog](https://techcommunity.softwareag.com/u/Ralph_Zbrog)\ **Post date:** [April 11, 2008, 6:14am UTC](https://techcommunity.softwareag.com/t/downward-compatibility/76536/1 "2008-04-11T06:14:34Z")
Can an NDV22 server run with a NAT41 environment? When we upgrade our Development environment to Natural 4.2, our Test environment will still be NAT41. Must we keep Test mapped to NDV21, or can we map both environments to the new NDV22 server? ---
**Author:** ![system](https://global.discourse-cdn.com/techcommunity/original/3X/c/d/cd19967bb605d28a72d77eb83a1cae22f3df2eb8.svg) [@system](https://techcommunity.softwareag.com/u/system)\ **Post date:** [April 11, 2008, 1:21pm UTC](https://techcommunity.softwareag.com/t/downward-compatibility/76536/2 "2008-04-11T13:21:09Z")
Ralph, no, NDV22 does NOT support NAT41. From [http://techcommunity.softwareag.com/ecosystem/documentation/natural/spod1107/ndv/zos/ndv/ndv-prereq.htm](http://techcommunity.softwareag.com/ecosystem/documentation/natural/spod1107/ndv/zos/ndv/ndv-prereq.htm) “Natural Development Server Version 2.2 supports Natural for Mainframes Version 4.2 in conjunction with Natural for Windows 6.2. Earlier Natural versions are not supported.” ---
**Author:** ![system](https://global.discourse-cdn.com/techcommunity/original/3X/c/d/cd19967bb605d28a72d77eb83a1cae22f3df2eb8.svg) [@system](https://techcommunity.softwareag.com/u/system)\ **Post date:** [April 2, 2021, 2:49pm UTC](https://techcommunity.softwareag.com/t/downward-compatibility/76536/3 "2021-04-02T14:49:21Z")