Unix Technical Forum

SEO

vBulletin Search Engine Optimization


Go Back   Unix Technical Forum > Unix Operating Systems > OpenBSD > comp.unix.bsd.openbsd.misc

Register FAQ Members List Calendar Search Today's Posts Mark Forums Read
  #1 (permalink)  
Old 02-16-2008, 06:41 AM
J. Graue
 
Posts: n/a
Default HOWTO use OpenBSD as on-demand dial-up gateway and firewall for LAN of Windows® systems

Hi, all:

I've slogged through getting an OpenBSD box functional as a firewall for a
LAN, but always with the (simplest) configuration of two NICs, one for
outside (xDSL, T-1, whatever), and one for inside, to the LAN. PF has been
very good... to me.

I'd like to create a LAN that will include an OpenBSD system. The OpenBSD
system will do dial-up on demand for the other systems, all MS® Windows®.
If anyone has any thoughts, hints or suggestions, I'd be very appreciative.
I'm having a hard time finding stuff on this sort of configuration, mainly
because, I think, no one uses dial-up, anymore!

The users will turn on the firewall/gateway, say, in the morning, leave it
on all day, use their Windows® systems, occasionally visiting the Internet.
I'm not sure if the phone line for data will be exclusively used for that;
it may also be needed for faxes. Of course, I know that while on the
Internet, the office will not be able to receive faxes. But, it means that
I can't just hog the line... I need to let it go after, say, 10 minutes of
idleness.

I'd like to figure out how to allow someone on the network the ability to
shutdown the firewall/gateway without having to login to the system (I'm
worried they'll freak out at having to look at a command-line), but that can
wait, unless someone has a suggestion.

Anyway, TIA.

Best regards,

Jim


Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
  #2 (permalink)  
Old 02-16-2008, 06:41 AM
sam
 
Posts: n/a
Default =?ISO-8859-1?Q?Re=3A_HOWTO_use_OpenBSD_as_on-demand_?==?ISO-8859-1?Q?dial-up_gateway_and_firewall_for_LAN_of_Win?==?ISO-8859-1?Q?dows=AE_systems?=

J. Graue wrote:

> Hi, all:
>
> I've slogged through getting an OpenBSD box functional as a firewall for a
> LAN, but always with the (simplest) configuration of two NICs, one for
> outside (xDSL, T-1, whatever), and one for inside, to the LAN. PF has been
> very good... to me.
>
> I'd like to create a LAN that will include an OpenBSD system. The OpenBSD
> system will do dial-up on demand for the other systems, all MS® Windows®.
> If anyone has any thoughts, hints or suggestions, I'd be very appreciative.
> I'm having a hard time finding stuff on this sort of configuration, mainly
> because, I think, no one uses dial-up, anymore!
>
> The users will turn on the firewall/gateway, say, in the morning, leave it
> on all day, use their Windows® systems, occasionally visiting the Internet.
> I'm not sure if the phone line for data will be exclusively used for that;
> it may also be needed for faxes. Of course, I know that while on the
> Internet, the office will not be able to receive faxes. But, it means that
> I can't just hog the line... I need to let it go after, say, 10 minutes of
> idleness.
>
> I'd like to figure out how to allow someone on the network the ability to
> shutdown the firewall/gateway without having to login to the system (I'm
> worried they'll freak out at having to look at a command-line), but that can
> wait, unless someone has a suggestion.
>

Just press the power off button, the system will fsck the filesystem
automatically when it rebooted next time.

Sam
> Anyway, TIA.
>
> Best regards,
>
> Jim
>
>

Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
  #3 (permalink)  
Old 02-16-2008, 06:41 AM
J. Graue
 
Posts: n/a
Default Re: HOWTO use OpenBSD as on-demand dial-up gateway and firewall for LAN of Windows® systems

Hello, Sam:

<SNIP everything else but this one issue that sam addressed>

> I'd like to figure out how to allow someone on the network the ability to
> > shutdown the firewall/gateway without having to login to the system (I'm
> > worried they'll freak out at having to look at a command-line), but that

can
> > wait, unless someone has a suggestion.
> >

> Just press the power off button, the system will fsck the filesystem
> automatically when it rebooted next time.
>
> Sam


Thanks for the suggestion. I would welcome any others' thoughts on this.
With all due respect to you, sam, I find this solution to be inelegant. If,
on the LAN-side, someone could, say, shutdown the dial-up gateway from a Web
page, that would be great.

If you have any thoughts on how I might go about configuring an on-demand
dialup gateway/firewall using OpenBSD, again, I would appreciate any input.

Best regards,

Jim


Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
  #4 (permalink)  
Old 02-16-2008, 06:41 AM
DoN. Nichols
 
Posts: n/a
Default Re: HOWTO use OpenBSD as on-demand dial-up gateway and firewall for LAN of Windows® systems

In article <1191s8epv2svm40@corp.supernews.com>,
J. Graue <info@nospam.com> wrote:
>Hello, Sam:
>
><SNIP everything else but this one issue that sam addressed>
>
>> I'd like to figure out how to allow someone on the network the ability to
>> > shutdown the firewall/gateway without having to login to the system (I'm
>> > worried they'll freak out at having to look at a command-line), but that

>can
>> > wait, unless someone has a suggestion.
>> >

>> Just press the power off button, the system will fsck the filesystem
>> automatically when it rebooted next time.


You didn't mention what the hardware was, so I don't know what
may be available.

With some hardware, the system can hold the power up after you
hit the power button until a complete and clean shutdown is performed.
On these, the power off button is a reasonable approach. However, if
the hardware does not support this, you could lose data as power drops
between the time a logical write to disk has occurred and the time that
the flush happens to assure a *physical* write to disk.

>Thanks for the suggestion. I would welcome any others' thoughts on this.
>With all due respect to you, sam, I find this solution to be inelegant. If,
>on the LAN-side, someone could, say, shutdown the dial-up gateway from a Web
>page, that would be great.


Hmm ... perhaps a CGI script -- ideally locked out of access
from outside, and available only to local IPs, which invokes the
following command line:

shutdown -h -p +5 web requested shutdown

You may wish to tune either the time or the message which follows the
time.

It might be a good idea to have the CGI script check the current time of
day and compare it to the normal working hours to decide whether to
honor the web-based request. Or -- if you can find out how many systems
are currently using the gateway, perhaps it should return a message
indicating how many users are on, and refusing until the number is down
to one.

>If you have any thoughts on how I might go about configuring an on-demand
>dialup gateway/firewall using OpenBSD, again, I would appreciate any input.


I've only covered possibilities for making the shutdown web
based to protect your users from the dreaded command line. However, it
presents some interesting opportunities for Denial Of Service attacks if
one of your internal users is feeling obnoxious. I would suggest that
the CGI script also log the IP address (and system name, if available)
for after-the-fact determination of the offending party.

Good Luck,
DoN.
--
Email: <dnichols@d-and-d.com> | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
  #5 (permalink)  
Old 02-16-2008, 06:41 AM
Chris 'Bob' Odorjan
 
Posts: n/a
Default =?ISO-8859-1?Q?Re=3A_HOWTO_use_OpenBSD_as_on-demand_?==?ISO-8859-1?Q?dial-up_gateway_and_firewall_for_LAN_of_Win?==?ISO-8859-1?Q?dows=AE_systems?=

On 05/20/05 6:58 PM, J. Graue wrote:

> The users will turn on the firewall/gateway, say, in the morning, leave it
> on all day, use their Windows® systems, occasionally visiting the Internet.
> I'm not sure if the phone line for data will be exclusively used for that;
> it may also be needed for faxes. Of course, I know that while on the
> Internet, the office will not be able to receive faxes. But, it means that
> I can't just hog the line... I need to let it go after, say, 10 minutes of
> idleness.


I did something similar before I had DSL; see the manual for ppp
(especially the section titled DIAL ON DEMAND) and
/etc/ppp/ppp.conf.sample for the details, but

set timeout 600

(assuming 10 minutes -- 600 seconds) and running it as

ppp -auto [system]

will do the trick. The userspace ppp software will always be running,
but will only dial the ISP when an outgoing packet is detected. It will
shutdown after 10 minutes of inactivity.

> I'd like to figure out how to allow someone on the network the ability to
> shutdown the firewall/gateway without having to login to the system (I'm
> worried they'll freak out at having to look at a command-line), but that can
> wait, unless someone has a suggestion.


The system I was using was on all the time, but someone else in this
thread suggested using a CGI script. A cron job could shut it down, but
might cause a problem for someone working overtime...

--
Chris Odorjan - bobnet@canada.com
Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
  #6 (permalink)  
Old 02-16-2008, 06:41 AM
sam
 
Posts: n/a
Default =?ISO-8859-1?Q?Re=3A_HOWTO_use_OpenBSD_as_on-demand_?==?ISO-8859-1?Q?dial-up_gateway_and_firewall_for_LAN_of_Win?==?ISO-8859-1?Q?dows=AE_systems?=

J. Graue wrote:

> Hello, Sam:
>
> <SNIP everything else but this one issue that sam addressed>
>
>>I'd like to figure out how to allow someone on the network the ability to
>>
>>>shutdown the firewall/gateway without having to login to the system (I'm
>>>worried they'll freak out at having to look at a command-line), but that

>
> can
>
>>>wait, unless someone has a suggestion.
>>>

>>
>>Just press the power off button, the system will fsck the filesystem
>>automatically when it rebooted next time.
>>
>>Sam

>
>
> Thanks for the suggestion. I would welcome any others' thoughts on this.
> With all due respect to you, sam, I find this solution to be inelegant. If,
> on the LAN-side, someone could, say, shutdown the dial-up gateway from a Web
> page, that would be great.
>
> If you have any thoughts on how I might go about configuring an on-demand
> dialup gateway/firewall using OpenBSD, again, I would appreciate any input.
>

Just install webmin in openbsd, you can remote admin the system thru its
web interface.

Sam
> Best regards,
>
> Jim
>
>

Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
  #7 (permalink)  
Old 02-16-2008, 06:41 AM
J. Graue
 
Posts: n/a
Default Re: HOWTO use OpenBSD as on-demand dial-up gateway and firewall for LAN of Windows® systems


"DoN. Nichols" <dnichols@d-and-d.com> wrote in message
news:d6r7io$17j$1@Fuego.d-and-d.com...

> In article <1191s8epv2svm40@corp.supernews.com>,
> J. Graue <info@nospam.com> wrote:
> >Hello, Sam:
> >
> ><SNIP everything else but this one issue that sam addressed>
> >
> >> I'd like to figure out how to allow someone on the network the ability

to
> >> > shutdown the firewall/gateway without having to login to the system

(I'm
> >> > worried they'll freak out at having to look at a command-line), but

that
> >can
> >> > wait, unless someone has a suggestion.
> >> >
> >> Just press the power off button, the system will fsck the filesystem
> >> automatically when it rebooted next time.

>
> You didn't mention what the hardware was, so I don't know what
> may be available.
>
> With some hardware, the system can hold the power up after you
> hit the power button until a complete and clean shutdown is performed.
> On these, the power off button is a reasonable approach. However, if
> the hardware does not support this, you could lose data as power drops
> between the time a logical write to disk has occurred and the time that
> the flush happens to assure a *physical* write to disk.
>
> >Thanks for the suggestion. I would welcome any others' thoughts on this.
> >With all due respect to you, sam, I find this solution to be inelegant.

If,
> >on the LAN-side, someone could, say, shutdown the dial-up gateway from a

Web
> >page, that would be great.

>
> Hmm ... perhaps a CGI script -- ideally locked out of access
> from outside, and available only to local IPs, which invokes the
> following command line:
>
> shutdown -h -p +5 web requested shutdown
>
> You may wish to tune either the time or the message which follows the
> time.
>
> It might be a good idea to have the CGI script check the current time of
> day and compare it to the normal working hours to decide whether to
> honor the web-based request. Or -- if you can find out how many systems
> are currently using the gateway, perhaps it should return a message
> indicating how many users are on, and refusing until the number is down
> to one.
>
> >If you have any thoughts on how I might go about configuring an on-demand
> >dialup gateway/firewall using OpenBSD, again, I would appreciate any

input.
>
> I've only covered possibilities for making the shutdown web
> based to protect your users from the dreaded command line. However, it
> presents some interesting opportunities for Denial Of Service attacks if
> one of your internal users is feeling obnoxious. I would suggest that
> the CGI script also log the IP address (and system name, if available)
> for after-the-fact determination of the offending party.
>
> Good Luck,
> DoN.
> --
> Email: <dnichols@d-and-d.com> | Voice (all times): (703) 938-4564
> (too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
> --- Black Holes are where God is dividing by zero ---


Thanks, DoN. Your suggestion is a good one, and I'll see what I can do.

Best regards,

Jim


Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
  #8 (permalink)  
Old 02-16-2008, 06:41 AM
J. Graue
 
Posts: n/a
Default Re: HOWTO use OpenBSD as on-demand dial-up gateway and firewall for LAN of Windows® systems


"sam" <root@localhost.com> wrote in message
news:d6rr8o$2s6i$1@news.hgc.com.hk...

<SNIP>

> > If you have any thoughts on how I might go about configuring an

on-demand
> > dialup gateway/firewall using OpenBSD, again, I would appreciate any

input.
> >

> Just install webmin in openbsd, you can remote admin the system thru its
> web interface.


I'll check into this. It's nothing with which I'm familiar, but I'm happy
to learn new things.

Best regards,

Jim


Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
  #9 (permalink)  
Old 02-16-2008, 06:41 AM
J. Graue
 
Posts: n/a
Default Re: HOWTO use OpenBSD as on-demand dial-up gateway and firewall for LAN of Windows® systems


"Chris 'Bob' Odorjan" <bobnet@canada.com> wrote in message
news:fnn7m2-tjr.ln1@bobnet.odorjan.ca...

> On 05/20/05 6:58 PM, J. Graue wrote:
>
> > The users will turn on the firewall/gateway, say, in the morning, leave

it
> > on all day, use their Windows® systems, occasionally visiting the

Internet.
> > I'm not sure if the phone line for data will be exclusively used for

that;
> > it may also be needed for faxes. Of course, I know that while on the
> > Internet, the office will not be able to receive faxes. But, it means

that
> > I can't just hog the line... I need to let it go after, say, 10 minutes

of
> > idleness.

>
> I did something similar before I had DSL; see the manual for ppp
> (especially the section titled DIAL ON DEMAND) and
> /etc/ppp/ppp.conf.sample for the details, but
>
> set timeout 600
>
> (assuming 10 minutes -- 600 seconds) and running it as
>
> ppp -auto [system]
>
> will do the trick. The userspace ppp software will always be running,
> but will only dial the ISP when an outgoing packet is detected. It will
> shutdown after 10 minutes of inactivity.
>
> > I'd like to figure out how to allow someone on the network the ability

to
> > shutdown the firewall/gateway without having to login to the system (I'm
> > worried they'll freak out at having to look at a command-line), but that

can
> > wait, unless someone has a suggestion.

>
> The system I was using was on all the time, but someone else in this
> thread suggested using a CGI script. A cron job could shut it down, but
> might cause a problem for someone working overtime...
>
> --
> Chris Odorjan - bobnet@canada.com


Thank you, very much, for addressing this and giving a hint. I'll dive in
and see if I can make this system do my bidding!

Best regards,

Jim


Digg this Post!Add Post to del.icio.usBookmark Post in TechnoratiFurl this Post!
Reply With Quote
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On
Forum Jump


All times are GMT. The time now is 05:19 PM.


Powered by vBulletin® Version 3.6.5
Copyright ©2000 - 2008, Jelsoft Enterprises Ltd.
SEO by vBSEO 3.2.0
UnixAdminTalk.com

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537