[conspire] (forw) Re: Need help with a couple technical questions

[Rick Moen]

----- Forwarded message from Rick Moen <rick at linuxmafia.com> -----

Date: Tue, 21 Jan 2014 16:49:27 -0800
From: Rick Moen <rick at linuxmafia.com>
To: Jennifer Chao <chlinlin66 at gmail.com>
Subject: Re: Need help with a couple technical questions
Organization: If you lived here, you'd be $HOME already.

Quoting Jennifer Chao (chlinlin66 at gmail.com):

> Hi Rick,
> 
> Happy New Year!
> 
> If you have a few minutes to help me find a solution to a couple tech
> questions would be great!
> 
> 1,  How would you go about adding 10x IPs to eth0 in Linux and Windows?
> 
> 2, How to connect a computer on the first floor to the network switch on
> the 15th floor. Distance is more  than 400 ft?
> 
> Thank you very much for reading my email.

Happy new year to you too, Jennifer.  (Greetings from Bora Bora, French
Polynesia.)

You add additional IP addresses to a network interface in Linux using a
technique called IP aliasing.  Here is a good tutorial:
http://www.cyberciti.biz/faq/linux-creating-or-adding-new-network-alias-to-a-network-card-nic/

As to MS-Windows, sorry, I am not an MS-Windows information resource.

The problem of network-connecting across 15 floors of a high-rise
building is a challenging one.  Your question does not state whether
this effort can/will be assisted by building management, which is
unfortunate, as the answer to that question  opens up or closes off
important options.

As you probably know, a single run of 100Base-T ethernet cabling overt
CAT6 cabling is rated for only about 300 feet.  However, old-style
10Base-2 coaxial 50 ohm ethernet cabling (called 'thinnet') can run for
600 feet (about 185 metres), and also is markedly more resistent to RFI
interference.[1]  So, for example, it is often used in office buildings to
connect between floors when the cabling must run near power cabling or
near elevator motors.

It would be difficult (effectively impossible) to run such a connection
vertically up 14 floors without participation from building management.
If (as seems likely) no such cooperation is available, you might be best
advised to try a point-to-point 802.11 wireless link with directional
antennas and see if you can receive enough signal at each end.
Unfortunately, transmitting through the middle of a solid building is a
very challenging use-case; the more-promising use cases involve links
between buildings where the antennas have line-of-sight communication.

[1] Transceivers to convert between coax ethernet and modern
twisted-pair ethernet are dirt-cheap at surplus outlets such as Halted
and Weird Stuff.


----- End forwarded message -----