Think ill start out with a short rant on how many newbies I see attempting to post replies as knowledgeable users. Don't claim to know things if you obviously cannot write a full sentence with punctuation. At any rate, I'm looking for a bit of advice (from the users who know things, preferrably) on my network gateway project:

I'm setting up to install open source FreeDOS onto an old 100mhz laptop, and its getting interesting. First off, I have an external cd-rom via a PCMCIA type 2 slot. (This is a TI extensa 510, which carries 2 type 2 slots.) Unfortunately, the generic cd-rom drivers on the bootdisk don't support an external PCMCIA cd burner. (I could simply install via 5 diskettes, but I'm curious, so bear with me.) I do have DOS compatable drivers for the CD-rom. How would I get those onto the bootdisk, so that they load with the OS and run?

Secondly, even if I get the cd drive working, I have another problem. The laptop has no built in ethernet. Rather it has dual identical 10mbps PCMCIA ethernet cards. These cards do not install manually via a .com file, they are initialized by an executable on the install disk. How would I find the neccessary .com drivers? And how do I get the computer to recognise two separate instances of the same drivers, and their associated hardware.

Third, once I get all that running, how difficult would it be to write a basic DOS firewall which block by default ALL traffic on all ports. The user than defines exacltly which ports are open and which are not. Can this firewall open and close ports dynmamically based upon whether or not they are in use? Finally can this firewall be accessed, and changed via a remote command prompt from inside the LAN without compromising the external wall?

I will try an answer what I can. Off the top of my head, I can give you answers to some of the questions but not all, bear with me:


1.

quote:

---

I do have DOS compatable drivers for the CD-rom. How would I get those onto the bootdisk, so that they load with the OS and run?

---

Assumption: FreeDOS uses Autoexec.bat and Config.sys files.

Response: In this case I would try and get the DOS drivers and load them a start time by adding appropriate entries into autoexec.bat and config.sys. Here are my old autoexec.bat and config.sys files from MSDOS:

[code=autoexec.bat]a:\mscdex /d:MTMIDE01[/code]
[code=config.sys]DEVICE C:\MTM\MTMCDAI.SYS /D:MTMIDE01[/code]

I could be wrong.

2.

quote:

---

How would I find the neccessary .com drivers? And how do I get the computer to recognise two separate instances of the same drivers, and their associated hardware.

---

Search for the Vendor and Model of your PCMCIA cards online with a google search and see if you can find DOS drivers.

+Vendor +Model +DOS +driver

I believe that the cards would be destiguished to the PC via differing I/O and IRQ addresses. The only problem might be you identifying or resolving how FreeDOS will deal with 2 NICs.

3.

quote:

---

how difficult would it be to write a basic DOS firewall which block by default ALL traffic on all ports. The user than defines exacltly which ports are open and which are not.

---

Depending on what you want your firewall to protect against. Firewall function is basic, you will write code that examines data attempting to move from the data-link layer (MAC) into the network layer (IP). Programming wize, I would say it would be a decent challange if you are not used to network programming, and depending on the Application Programming Interface (API) you have to work with, it could either be easy, or a total mess.

4.

quote:

---

Can this firewall open and close ports dynmamically based upon whether or not they are in use?

---

That is called either a reflexsive firewall or in a more advanced state, a content filterning firewall. A reflexsive system works by allow all but specifically blocked traffic out, while only allowing data back in that is part of a "session". You determine this by looking at the ACK and RST bits in the TCP headers, thus this only works at keeping out TCP traffic, any other traffic will not be allowed back in (ICMP, UDP, IPX).

5.

quote:

---

Finally can this firewall be accessed, and changed via a remote command prompt from inside the LAN without compromising the external wall?

---

You could do this by using authentication and dynamic firewalling. You can use an authentication scheme (RADIUS) to authenticate you from anywhere on the net and allow connections from your location into the network/server. This of course, is getting more advanced.

Another options, which I doubt is even one for you, is dialup console access. I don't know if FreeDOS does any of this stuff. Plus, to make dialup connections secure, you must setup "call back".


Phew.

To finish off: There must be a good reason that you are trying to do all of this with FreeDOS? Linux will do all of this very well, except for content filtering... In my opinion it would be a much better route to go. You also have many other unix variants that apply well to this role. NetBSD, OpenBSD, FreeBSD.

there is even a floppy distro of linux that wil act as a firewall and router. i assume it will take care of your gateway issue without a problem.


im guesing your using free dos for the chalenge right?

shit, i cant even read this shit im so confused

Tylerde, yes, the post is intented to require a good deal of computer knowledge before you can respond in any meaningful fashion.

Syphon: yes I am doing it partly for the challenge, but also partly for another reason:
1)I know the Linux Router Project (on a floppy) is out there, but I think it's been discontued and i cant find a place to download it from.
2) The machine I am installing on has no built in cd rom support, and no bootdisk will carry PCMCIA cd-rw drivers. I also cannot install linux off of ftp (SuSe offers this; speed is 10kbps which translates to like 2 days, and it required at MINIMUM 64 mb ram. This computer has 16.)
The other benefit to DOS is hardware support. Since FreeDOS is similar to MS dos, I can count on working drivers for all of my hardware, including the cd rw.

I can get everything onto the hard drive now, fortunately freedos is available as 2-5 floppy images. But i'm waiting to see if I can get the dual ethernet card drivers running in DOS 7, and make sure the router program runs before I install a new OS.

Cense, I have the cd rom and ethernet drivers already, I dont need to get them off the net. They are on separate install diskettes for each piece of hardware, and the ethernet drivers dont tell me anything about where it has copied the .com files when I install them. I dont even have filenames. Can an exe initialize the card to run without a driver just by setting the hrz, irq, and a few other things?

[This message has been edited by Dr Spock (edited 10-29-2002).]

5 different suitable linux distros.
http://www.fli4l.de/english/e_fli4l.htm
http://www.freesco.info
http://www.zelow.no/floppyfw/
http://www.ecks.org/projects/loaf/
http://www.smoothwall.org/


If it's just for the challenge, I'm not quite clear whether or not it is, then in that case, more power to you. Dos is something I'm without knowledge in, but I'd love it if you posted a description of your process after you finished it...