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Use the latest DUN & Network available

The DUN12 upgrade is an improved version of Microsoft's original DUN. The first DUN12 upgrade was faulty and was replace. DUN12b is widely used.

DUN13 is the latest freely available DUN update and is part of Win98, SE, and ME. Some Windows 95 users have reported problems with DUN13.

Winsock2 is now the standard Windows socket software.


DUN12 is widely used

Microsoft has released a new Dial-Up Networking (DUN), DUN12 version 1.2b (msdun12.exe 1,424Kb). Note the b in 1.2b; there has been a version 1.2 that should NOT be used. Both are called DUN12, but the earlier version is likely to have disappeared from the Microsoft site by now.

It is definitely an improved version even though it does not correct the TCP/IP problem.

The 1.2b version seems to work fine, so we can assume all is well. It also contains an update to your Winsock which must also be installed (first).

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Dial-Up Networking 1.2 Upgrade replaces all of the Dial- Up Networking components, and installs new versions of the TCP/IP stack and the NDIS layer. A new version of Winsock is included to correct name resolution limitations in the original Windows 95/98 software.

The Dial-Up Networking 1.2 Upgrade can be applied to existing Window 95/98 based computers, including the retail release and OEM Service Release 2 (OSR2).

• DUN12 upgrades the information in system monitor. Scripting is now built in (should you require it). You can configure it so that applications can dial out without asking (should you require it) - double-click My Computer, and select Dial-up Networking - select Connections • Settings.

• DUN 12 installs a correction for DIR and DATE relating to the Year 2000 (it does not update or Winfile.exe - these are updated by Microsoft's Y2K update, win95y2k.exe).

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• DUN 12 also installs Virtual Private Networking (VPN). This is Point-to-Point Virtual Private Networking. It can be removed (unless specifically required) - via Control Panel • Add/Remove Programs • Windows Setup • Communications (read next).

• Please remember that Microsoft says " Do not add or remove individual Dial-Up Adapter or Virtual Private Networking Adapter components via the Network Control Panel applet or from the Device Manager tab of the System applet". You can look for, and remove, any remaining VPN settings in Control Panel • Network after using Add/Remove.

An uninstall of the Dial-Up Networking 1.2 Upgrade will completely remove Dial-Up Networking from your system, including any features that depend on it.

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Winsock2 is a complete redesign of the Winsock architecture. Winsock2 consists of an updated TCP/IP stack, updated TCP/IP utilities and updated Winsock 2 components. It fixes several problems including slow performance with some IPX applications and incompatibility with Internet Explorer 4.0 that could cause a page fault.

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There's a slight problem!

1. A new Winsock update comes with DUN12, a revised version of Winsock 1.1. This version represents a minor change over the Winsock that was originally delivered with Windows95. You must install the Winsock update BEFORE you run DUN12. If you don't upgrade your Winsock, you may encounter situations in which host names are not recognised.
2. If you wish to use the new Winsock2 (ws2setup.exe, 936K) you MUST install DUN12 FIRST, and then install Winsock2. Failure to do so will result in DUN12 overwriting some newer files installed by the Winsock2 upgrade. Should you choose to uninstall this program, do so in Windows Safe Mode and be logged off.

msdun12.exe DUN12 b
ws2setup.exe Winsock2

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Suggested Order of Installation

1 UnimodemV driver (for Windows 95A), and reboot
2 DUN12, but do NOT run it yet
3 WSOCKUPD - this is the Winsock update that comes with DUN12 and must be installed before DUN12 is RUN. It is NOT Winsock2. You will find it (after installing DUN12) in _:\Windows\MSDUN\
4 Reboot now (it is OK to run DUN12 now)
5 Winsock2 now, and reboot

There have been suggestions that Winsock2 should be installed when in Safe Mode. This Site can not confirm that this is necessary, and does not use Safe Mode for its installation. Feedback on this will be appreciated.

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DUN13 (2.2MB) was released by Microsoft in Sept 1998. This basically adds Windows 98 connection functionality to Windows 95. It is still too soon for a proper assessment.

The new version sets the IPMTU (was MTU) automatically depending on what speed you are connected at. This is not necessarily good for your transfer speeds as there may be continuous time-wasting readjustments, and will possibly prevent you from correcting the MTU yourself - apparently it continues to self-adjust.

98+ DUN13 is packaged with Windows 98 and appears to be satisfactory.

95 Some 95 users (mostly OSR2) have had a few problems. Version 1.3 may also be very difficult to uninstall fully - be prepared to remove the entire comms package if you find it unsatisfactory. If DUN12 is working correctly then perhaps you should stay with it for now. Caution is advised for the time being.

If you install it or have Win98, then look in Control Panel • Network • Dailup adapter and set the Packet Size to small which sets it to 576. The three settings available appear to be for 576 (small), 1000 (medium), and 1500 (large).
DUN 1.3

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• If you have already used the MTU-Speed utility, you can initially set these four settings to Remove (allowing Windows 95/98 to use it's new defaults) - MaxMTU, RWIN, MTUAutoDiscover and MTUBlackHoleDetect . You can return to this utility to reset MTU to 576 and, probably, RWIN to 2144; some users have claimed they do not require this adjustment after DUN 12b is installed - it is likely you will need to use MTU-Speed.

• Make sure you do not have multiple copies, or an incorrect version, of Winsock installed on your computer, especially in _:\windows or in _:\windows\system; this can confuse Windows 95/98 and cause (dialling) problems. You should rename these prior to deletion (e.g. wsock32.old), retaining only the correct version.

You can expect to find winsock.dll in _:\Windows (it is normal to find a backup in _:\Windows\SYSBCKUP, and also another backup in _:\Windows\ws2bakup if you installed Winsock2)

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• You can expect to find wsock32.dll in _:\Windows\SYSTEM (it is normal to find a backup copy in _:\Windows\ws2bakup if you installed Winsock2)    
• Winsock2 creates a backup of your older Winsock in _:\Windows \ ws2backup for easy re-installation, if required (Run the MS-DOS Batch File ws2bakup.bat in a DOS window). It also installs a ws2relnotes.htm which you should read.
• There are reports that Winsock2 has caused problems on some systems that are using a pre-release versions of Internet Explorer 4 - video or IE4 troubles.
• Should you decide to uninstall this Winsock2, be sure to do so in Windows Safe Mode, and log off if you are connected!

128-bit encryption: A separate utility Dun128.exe is available which will modify an MSDUN 1.3 installation to enable use of 128-bit encryption. It must only be used with DUN13.

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Please remember that you alone are responsible for the consequences of any changes you make to your computer hardware or software.

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