Insanity.
Noun. Doing the same thing over and over again to see if it'll get a different result. See also: UDP (User Datagram Protocol)
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Tag: networking
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Just when you thought it was safe to route packets...
One of the most arcane yet commonly encountered pieces of equipment on the Net today are routers - devices (usually big, expensive devices) that look at the destination IP addresses of each packet they see and decide which port to throw them out of to help them on their way. Usually you don't see them up close because they tend to live in data centers or wiring closets (for smaller shops) in racks, safely locked away. While there are a couple of manufacturers out there who specialize in them, for people in the know the first thing they think of when …
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Belated LayerOne entry number one.
I made it to the LayerOne conference safe, sound, and on a shuttle bus that runs from the Bob Hope Airport in Burbank, California to the Hilton in Pasadena. Travel tip: If you can avoid it, don't catch a cab, they cost an arm and a leg. If you can charter a shuttlebus you'll pay much less for the trip. A cab ride would probably have cost me about $70us, while I paid all of $23us for a leisurely ride to the hotel, in air conditioning (not that we needed it) and comfort. Of course, I hadn't been there for …
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A Faraday cage in a can!
Wireless networking is a neverending headache for system and network admins, and not just because some makes and models of access points are so flaky, the could have come out of a box of cereal. When you crank up an RF transceiver, the signals go everywhere, which means that people outside of a building can at least see some traffic beyond the walls, and sometimes beyond the property line. I don't think that I have to go into what a security threat this is... normally, you can use a Faraday cage to contain the signals, but building such a construction …
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Changing the IP address of a Solaris 10 machine.
- Edit /etc/hosts, change the IP address corresponding to the system's hostname.
- Edit /etc/netmasks, change the network and subnet mask.
- If required, edit /etc/defaultrouter and set the new default gateway of the system.
- Edit /etc/inet/ipnodes, change the IP address of the system's hostname. This file trumps all of the other TCP/IP config files, so if you miss this file everything else is pointless. Alternatively, you can delete or rename this file, and this will trick the Solaris 10 SMF subsystem into thinking it's an IPv4-only system.
- shutdown -i 6 -y -g 5 to reboot the …
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DNS greylisting to lessen the amount of incoming spam.
Greylisting is a technique for slowing down the oncoming torrent of spam on the Net today by breaking spamware that isn't compliant with the SMTP RFCs. It consists of a simple alteration to your DNS zonefiles that places an IP address that doesn't have anything listening on port 25/TCP in the position of your primary MX, and the addresses of your real MX's in positions of lower priority in you DNS zone. Spamware that isn't compliant looks at your DNS records for the IP address of the primary MX, tries to contact it, fails, and gives up, or at …
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Random knowledge X.
How to set up a crossover ethernet connection between two Sun Solaris machines:
- Connect both machines using a crossover ethernet cable.
- root@solaris-machine-1# ifconfig
plumb - root@solaris-machine-1# ifconfig
netmask - root@solaris-machine-1# ifconfig
up - On each machine, ping the other. If both are reported as being alive, you're golden.
It would look something like this on a live setup:
root@igg# ifconfig ce1 plumb
root@ook# ifconfig ce1 plumb
root@igg# ifconfig ce1 10.0.0.1 netmask 255.255.255.0
root@ook# ifconfig ce1 10.0.0.2 netmask 255.255.255.0
root@igg# ifconfig ce1 up
root …Read more...
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Intel is the first to market with a consumer implementation of 802.11n.
Intel has released an implementation of the draft 802.11n wireless networking protocol for laptops and other portable devices. 802.11n has five times the maximum data throughput of 802.11g, topping out at 270 megabits per second. On top of that, their 802.11n chipset uses less power than the other wi-fi implementations out there, which can give laptops an extra hour of runtime on battery, which is a huge selling point.
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Artifically constructed extension nerves!
New and interesting developments in the field of neuroprosthetics! Researchers at the University of Pennsylvania are culturing living data cables by stretching nerves! Because nerves do not mix well with nonorganic structures unless they are coated with organic compounds and practically grown there, the most ideal way of growing nerves is to take a section of viable nerve tissue, culture it in a growth medium, and slowly stretch the section of nerve. The idea is that the neurons are stretched away from one another, so the neuronal bodies and axons will lengthen to fill the space. Interestingly, nerves will stretch …
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