Author Topic: OS/2 IP Stack Hardening  (Read 292 times)

ChrisGWarp

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OS/2 IP Stack Hardening
« on: December 14, 2025, 05:39:43 am »
Hi everyone.
I still (sometimes once a week) get kernel traps in the IP layer. Internet facing.
Has anyone published some details or a guide on the best hardening/tuning settings to be able to use on the stack?

Cheers,
-Chris

Dave Yeo

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Re: OS/2 IP Stack Hardening
« Reply #1 on: December 14, 2025, 08:25:45 am »
Have you looked at the included documentation? Computer-->Help Center-->Information-->Components & Features-->Networking-->TCP/IP In particular, the TCP/IP Command Reference, inetcfg is one command to search for tuning. Lots of other stuff under TCP/IP too.
There's a few threads on here about the various settings inetcfg handles.
Crashes aren't good, you might want to open an issue at Arca Noae assuming you have a current subscription.

Dariusz Piatkowski

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Re: OS/2 IP Stack Hardening
« Reply #2 on: December 14, 2025, 02:37:32 pm »
Dave Yeo has great advice, inetcfg has been extensively discussed on our forum, the search function will bring up a bunch of stuff.

The starting point though is to understand where you are in terms of your OS/2 version and the TCP/IP stack itself. There were numerous IBM fixes and Alex Taylor's Visual Guides can make a quick work of trying to figure it all out otherwise, so head on over to => http://www.altsan.org/os2/fixpaks/tcpip.html to take a look at what that looks like.

More specifically re: the trap, what are you actually seeing?

RTAN

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Re: OS/2 IP Stack Hardening
« Reply #3 on: December 14, 2025, 09:40:48 pm »
To echo Dariusz's point, could you tell us exactly what version of OS/2, MPTS/LAPS and TCP/IP you're running. Running SYSLEVEL from the command prompt will tell you if you're not sure. Alternatively tell us what FixPaks you've applied and we can work it out from there.

Alex's guide is indeed excellent and I have used it many times myself to work out exactly what level of MPTS & TCP/IP I can safely reach with any given version of OS/2!

Richard.

ChrisGWarp

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Re: OS/2 IP Stack Hardening
« Reply #4 on: December 15, 2025, 06:30:56 am »
I have two machines, main and inet.

The trimmed syslevel output from inet is:

Code: [Select]
C:\IBMCOM\SYSLEVEL.TRP
IBM OS/2 LAN Adapter and Protocol Support
Version 5.50     Component ID 5639A5700
Current CSD level: WR08620
Prior   CSD level: WR08610

C:\IBMINST\SYSLEVEL.WSB
OS/2 Warp Server for e-business
Extended Edition 4.50     Component ID 5639F9300
Type 0
Current CSD level: XR04500
Prior   CSD level: XR04500

C:\MPTN\SYSLEVEL.DHC
IBM OS/2 Dynamic Host Configuration Protocol Services
Version 4.21     Component ID 562290901
Current CSD level: WR08620
Prior   CSD level: WR08610

C:\MPTN\SYSLEVEL.MPT
IBM OS/2 TCP/IP Stack
Version 5.50     Component ID 5639B1700
Current CSD level: WR08620
Prior   CSD level: WR08610

C:\MPTN\SYSLEVEL.NFS
NFS for TCP/IP on OS/2
Version 3.00.1     Component ID 5639A6602
Current CSD level: UN02100
Prior   CSD level: UN02000

C:\OS2\INSTALL\SYSLEVEL.OS2
Warp Server for e-business Base Operating System
Version 4.50     Component ID 5639A5550
Type 0S
Current CSD level: XR04500
Prior   CSD level: XR04500

C:\TCPIP\bin\SYSLEVEL.DDN
IBM OS/2 Dynamic Domain Name Server
Version 4.21     Component ID 562293600
Current CSD level: UN02100
Prior   CSD level: UN02000

C:\TCPIP\bin\SYSLEVEL.DHS
IBM OS/2 Dynamic Host Configuration Protocol Server
Version 4.21     Component ID 562293700
Current CSD level: UN02100
Prior   CSD level: UN02000

C:\TCPIP\bin\SYSLEVEL.IAK
 IBM Internet Connection for Warp
Version 4.21     Component ID 5639A6400
Current CSD level: UN02100
Prior   CSD level: UN02000

C:\TCPIP\bin\SYSLEVEL.TCP
IBM TCP/IP for Warp                                         
Version 4.21     Component ID 5639A6600
Current CSD level: UN02100
Prior   CSD level: UN02000


The trimmed syslevel output from main is:

Code: [Select]
C:\IBMCOM\SYSLEVEL.TRP
IBM OS/2 LAN Adapter and Protocol Support
Version 6.01     Component ID 5639A5700
Current CSD level: WR08705
Prior   CSD level: WR08701

C:\IBMINST\SYSLEVEL.WSB
Convenience Package - OS/2 Warp Server for e-business
Version 4.52     Component ID 5639F9301
Type 0C     
Current CSD level: XR04502
Prior   CSD level: XR04501

C:\MPTN\SYSLEVEL.DHC
IBM OS/2 Dynamic Host Configuration Protocol Services
Version 4.31     Component ID 562290901
Current CSD level: WR08705
Prior   CSD level: WR08701

C:\MPTN\SYSLEVEL.MPT
IBM OS/2 TCP/IP Stack
Version 6.01     Component ID 5639B1700
Current CSD level: WR08705
Prior   CSD level: WR08701

C:\MPTN\SYSLEVEL.NFS
NFS for TCP/IP on OS/2
Version 3.00.3     Component ID 5639A6602
Current CSD level: UN02205
Prior   CSD level: UN02200

C:\OS2\INSTALL\SYSLEVEL.OS2
Convenience Package - OS/2 Warp Server for e-business
Version 4.52     Component ID 5639A6150
Type 0C
Current CSD level: XR04502
Prior   CSD level: XR04502

C:\TCPIP\bin\SYSLEVEL.DDN
IBM OS/2 Dynamic Domain Name Server
Version 4.32     Component ID 562293600
Current CSD level: UN02205
Prior   CSD level: UN02200

C:\TCPIP\bin\SYSLEVEL.DHS
IBM OS/2 Dynamic Host Configuration Protocol Server
Version 4.32     Component ID 562293700
Current CSD level: UN02205
Prior   CSD level: UN02200

C:\TCPIP\bin\SYSLEVEL.TCP
IBM TCP/IP for Warp                                         
Version 4.32     Component ID 5639A6600
Current CSD level: UN02205
Prior   CSD level: UN02200

C:\TCPIP\bin\SYSLEVEL.VPN
IBM TCP/IP VPN for Warp                         
Version 4.32     Component ID 5639A6601
Current CSD level: UN02205
Prior   CSD level: UN02200

These machines were built 25+ years ago, and may have been partially patched, meaning that the syslevel files should be mostly correct. ;)

I do remember seeing years ago some tuning of the IP stack parameters, which is what triggered the question.

Cheers,
-Chris

Lars

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Re: OS/2 IP Stack Hardening
« Reply #5 on: December 15, 2025, 09:29:55 am »
So, what machine gives you problems ?

It is obvious that "inet" is outdated and has no convenience package installed, in contrast to "main" which seems up-to-date.

And from Alex' website, I deduce that if you install convenience package 2 for WSeB, then that includes updates to the TCP/IP stack. Once you have done that, you can potentially install further updates as per Alex' website.

ChrisGWarp

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Re: OS/2 IP Stack Hardening
« Reply #6 on: December 15, 2025, 11:23:41 pm »
Both go. Monthly at least.

I've tried applying CP2 to one of the machines, but it kills my desktop, so I gave up and copied the stack across from the machine that did work.

Patches are only a part of the problem.

The other, is what I was originally asking for, the hardening/tuning settings that can be applied to the stack to better protect it. Is there a list of settings and recommendations/script to run? That's exactly that I'm looking for.

Cheers,
-Chris