3 edits | reply to SpannerITWks
Re: 100% Security During Boot 4 Peanuts !
Version 2 |
Taking on board the useful suggestion about the relay switching the Line instead of the Modem Power, i have slightly redesigned the circuit to accomplish this.
You still need to provide a 5 Volt Power source to the circuit of course. This could still be tapped off the Modem Power, or via an outlet on the PC, or a seperate DC supply of around 4.5 to 6 Volts.
You only need to break the connection to one wire in the line feed. One goes to LINE IN and the other goes to LINE OUT on the OPEN relay contacts. It does NOT matter which way round they go on this Version 2.
I would recommend in this Version to buy a relay with Silver or Gold contacts, most minitature ones are and still cheap.
Thanx for the helpful comments and kind words about it and me. I'd be interested to hear peoples feedback from anyone who installs it.
By the way I is a HE lol.
Regards,
Spanner
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I Only Know What I Know But I'm Learning all The Time -
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Spanner intheWorks
/SpannerITWks |
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 EGeezerSummertimePremium
join:2002-08-04
Midwest
kudos:7
 ·Callcentric
2 edits | Re: Relay switching idea - Actually, I like the power switch - quite simple and creative I'd use the variable resistor idea with that to set my delay time if I were using it.
For the CAT5 switch, one would need to test to find a relay that would switch all the signal carrying wires and not introduce EMF or reactance into the CAT5 line, altering the efective impedance or introducing noise into the wire.
Open loops could also act as antennas introducing stray noise that might produce interesting results as the NIC picks them up. For that case, you might need a DPDT relay with the "off" position terminating in a dummy load.
Although routers, firewalls, Surfboards etc are good pieces of protection, The time-delay power relay is a novel way to satisfy someone's need for extra caution. I enjoy creative and simple answers to technological issues and hope someone breadboards it and reports back... 
Edit
One thought - wouldn't there be issues when the modem goes up after the PC? If the PC gets IP from DHCP provided through the modem, it would need to retry - or you'd need to batch execute ipconfig /renew /all after modem power up for some systems.
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 novaflareThe Dragon Was HerePremium
join:2002-01-24
Barberton, OH | reply to SpannerITWks
Re: 100% Security During Boot 4 Peanuts ! you can get realy cool stuff going with this. How bout this one trigger the relay by computer poer. Hooked inline with the led for the case. Each computer could have its own relay that kils its own cat 5. No isues with the cat 5 relay being tripped while you want it on this way ither.Course with routers you dont need to worry about this so much but this would be great for a hub or bridge. Spanner has most asuradly came up with something worth while. Even if you are 99.9999% sure your firewall protects during all phases of boot you just never know. I mean what if your firewall stops protecting during boot or what if theres 3 secounds where it infact doesnt protect when you need protection. Timing a relay switch out so that it only conects the cat 60 secounds after it recieves its power will asure protection.
For us lowly end users this may not be a big deal and the slight risk is something we are willing to take. But how much youwant to bet this shows up in some corp invironment some where?
And heres somethign i bet no one even thought of. Its possible with a small amount of coding in the language of your choice to send data out a serial port any kind of data you like. This data could be say running proccess list or a single running procs name. Or maybe you use a trigger event in your program that breaks the connection toyour cat 5 if a proc stops running. To date while i cant remember what firewalls had it happen i remember hearing about 3 that had trojans disable them includign killing the proccess. This of course would allow full access to your computer. Well spanners idea taken to the next step could stop things like this dead.
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DSLR security chat at us.ausirc.net chanel #dslr_sec lets pack this channelopen source dns server for *nix and windows »powerdns.com |
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BPremium,MVM
join:2000-10-28
1 edit | reply to EGeezer
Re: Relay switching idea - DHCP under Windows these days is really pretty good about that. I've seen addresses come up nearly instantly the moment the DHCP server was back on-line.
The problem is more on the boot side. It can take many seconds longer to boot as the machine searches in vain for its address.
Of course, I prefer static IP addressing in home networks anyway.
-- B
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In a realm outside causality and function |
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EGeezerSummertimePremium
join:2002-08-04
Midwest
kudos:7 Reviews:
·Callcentric
| Hi B  ,
Good points - I note, though, that WIN98 ain't too good at recovery or initialization compared to XP/2K/2K3.
I use statics on stuff behind a router and NAT and disable DHCP, but the single PC behind a DSL/Cable modem still looks for DHCP and, particularly if it's WIN9X, craps out if the modem isn't there.
(corrections welcome!)
EG |
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BPremium,MVM
join:2000-10-28 | I don't think it craps out permanently in Win9x. It can just take a really long time. The only time I've seen it regularly fail to boot is if the Novell client is installed.
That thing just sucks.
-- B
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In a realm outside causality and function |
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