Connecting 2 computers with a non-crossover ethernet cable - Page 1
Forum section: electronics / general

author: nuno
author_rank: Frequent Contributor
timestamp: November 07, 2014, 05:24:06 pm
content: If none supports the "auto config", can I harm any of them? One is an HP pavillion from 2006 with a 100MBit/s card, the other is actually a recent IP webcam.

author: suicidaleggroll
author_rank: Super Contributor
timestamp: November 07, 2014, 05:27:47 pm
content: No it won't damage anything, you just won't get any communication if neither of them is capable of automatically switching.

author: tszaboo
author_rank: Super Contributor
timestamp: November 07, 2014, 05:42:21 pm
content: I wasnt able to connect a NAS to my PC with a cross cable, or with an unmanaged switch, I needed a router. But I'm a networking noob.

author: suicidaleggroll
author_rank: Super Contributor
timestamp: November 07, 2014, 05:47:21 pm
content: Quote from: NANDBlog on November 07, 2014, 05:42:21 pmIf there is no DHCP server in the network (eg: just an unmanaged switch or a direct connection) then you need to manually set a static IP for both devices on the same subnet.

author: Rigby
author_rank: Super Contributor
timestamp: November 07, 2014, 05:51:46 pm
content: Quote from: suicidaleggroll on November 07, 2014, 05:47:21 pmWindows sets up autoconfig addressing that doesn't require DHCP to assign addresses. These are the addresses you see when you have a link to another device but nothing else is present. They are addresses that begin with 169.254, and are reserved for autoconfig addresses like that so they aren't used elsewhere.http://en.wikipedia.org/wiki/Link-local_addressin short, dhcp isn't required. you can get from here to there without DHCP or manual IP configuration thanks to link-local autoconfig addressing.

author: tszaboo
author_rank: Super Contributor
timestamp: November 07, 2014, 05:55:06 pm
content: Quote from: suicidaleggroll on November 07, 2014, 05:47:21 pmI've figured so much, but how do you login to the NAS to set the IP(bringing it to your neibourgh doesnt count)?

author: miguelvp
author_rank: Super Contributor
timestamp: November 07, 2014, 05:57:46 pm
content: Quote from: NANDBlog on November 07, 2014, 05:42:21 pmBuy a cheap network switch.Hubs used to be cheaper but now switches are so cheap, that you can't find hubs that easily anymore

author: suicidaleggroll
author_rank: Super Contributor
timestamp: November 07, 2014, 06:07:38 pm
content: Quote from: NANDBlog on November 07, 2014, 05:55:06 pmI'm sure it depends on the NAS, but the universal way would probably be to hook it up to some DHCP network, get the address, log into its config page, set it to some new static address, and then pull it off of the DHCP network and direct-wire it as desired. Most people have a DHCP router sitting around in their attic somewhere, or if absolutely necessary you could install a DHCP server daemon on your computer temporarily.I wouldn't be surprised if some NAS devices have a serial console port or USB port that you could use to configure it as well.

author: suicidaleggroll
author_rank: Super Contributor
timestamp: November 07, 2014, 06:10:32 pm
content: Quote from: Rigby on November 07, 2014, 05:51:46 pmI've never heard of that, but then again I don't use Windows very often. Does Windows provide an autoconfig address to the device you're connecting to as well? If not, then I don't see how this would accomplish much, other than when you're connecting two Windows boxes to each other, which I can't imagine is that common.

author: nuno
author_rank: Frequent Contributor
timestamp: November 07, 2014, 06:14:25 pm
content: Eheheh... thanks guys, it's working now. This week I bought this Apexis IP wireless Cam but the wireless needs to be enabled, by 1st accessing the cam's integrated website through ethernet. I have no switch/hub/router at home, just a WAN -> local wireless tiny TPlink box.So I open the cam (was also curious; they use step motors for cam position and Nuvoton or similar for an ARM SoC and some other chip, ethernet I think) and quickly found a suggestive PCB unpopulated "3V3, GND, TX, RX" footprint. Soldered a piece of ribbon cable, to an UART-RS232 adapter to an USB-RS232 adapter and voilá, a basic linux console (I can see the bastard keeps trying to connect towww.apexisipc.com). There I was able to manually set up an IP address and mask (ifconfig eth0 ...), in the same network that windows picked up when I connected my PC to the cam using a normal cable (it works). I can now access the cam's site from my PC and am now setting up the wireless network.I had tried to configure the wireless on the linux console, but I have no experience with that so I failed, or maybe it needs the wifi card to be enabled somehow I couldn't find out.Yes, once Windows gets ethernet connected, if it can't find some a gateway or something, it will auto set an ip and netmask. Just check ipconfig.

author: Rigby
author_rank: Super Contributor
timestamp: November 07, 2014, 06:23:06 pm
content: Quote from: suicidaleggroll on November 07, 2014, 06:10:32 pmMany devices and operating systems support it.Windows can't tell another device what IP to use. That's DHCP.

author: SirNick
author_rank: Frequent Contributor
timestamp: November 07, 2014, 07:22:44 pm
content: Quote from: suicidaleggroll on November 07, 2014, 06:10:32 pmIt's very common. Part of the design goal, from what I read way back when, was to allow partial connectivity in business environments when the site DHCP server was unavailable for some reason. Dubious advantage, since these days you aren't going to get very far on NetBIOS alone, but hey.It's an actual standard though. There's an RFC for the IP block and everything. It's not just a Microsoft thing.

author: tszaboo
author_rank: Super Contributor
timestamp: November 08, 2014, 06:28:22 pm
content: Quote from: suicidaleggroll on November 07, 2014, 06:07:38 pmI was waiting for my internet provider to finally send a technician and install my net. It took them a month. Internet is like in the dark age here. So the IP sent me their stupid router, and I was counting on that, and that of course solved the problem. In the meantime, I was trying to access my data, but that wasnt a big deal anyway.

author: eurofox
author_rank: Unknown
timestamp: November 08, 2014, 07:11:56 pm
content: Quote from: NANDBlog on November 08, 2014, 06:28:22 pmI don't have any problem with my internet provider, I think you use the wrong one

author: mariush
author_rank: Super Contributor
timestamp: November 08, 2014, 08:26:55 pm
content: If both computers have gigabit network cards, the cards should automatically detect the cable wiring (the transmit and receive channels) and a connection should be established and everything should work even if it's not a crossover cable. Though keep in mind there are some Realtek chips out there with bugs in them that make this auto detection feature not work.With 100 mbps network cards, you won't have any problems, but it also wouldn't work.As for creating a network quickly, I typically just set the ip manually on both computers ... 192.168.0.1 , .2 and subnet mask 255.255.255.0 on both... that's all there is to it. Then I can use Windows Share or a simple ftp server and client like Filezilla ftp server / client if I need to transfer huge amount of data (with resume and multiple download threads to saturate the bandwidth)

author: tszaboo
author_rank: Super Contributor
timestamp: November 09, 2014, 06:40:35 pm
content: Quote from: eurofox on November 08, 2014, 07:11:56 pmI could chose between the 100Gb limited (in the 21 century. On a cable! I could not believe when the guy said it), the expensive and this one. I mean I moved here 2 years ago, it was shocking, how bad it is.