https://community.hpe.com/t5/switches-hubs-and-modems/networking-basic-question/m-p/3454014#M4320 Hi,<BR /><BR />why do you need to use RJ-45 cross-over cable between two swithches and why you need to use straight RJ45 cable between PC-switch.<BR /><BR />regards<BR />chakri Mon, 03 Jan 2005 08:17:48 GMT Chakravarthi 2005-01-03T08:17:48Z https://community.hpe.com/t5/switches-hubs-and-modems/networking-basic-question/m-p/3454014#M4320 Hi,<BR /><BR />why do you need to use RJ-45 cross-over cable between two swithches and why you need to use straight RJ45 cable between PC-switch.<BR /><BR />regards<BR />chakri Mon, 03 Jan 2005 08:17:48 GMT https://community.hpe.com/t5/switches-hubs-and-modems/networking-basic-question/m-p/3454014#M4320 Chakravarthi 2005-01-03T08:17:48Z https://community.hpe.com/t5/switches-hubs-and-modems/networking-basic-question/m-p/3454015#M4321 MDI ports have the receive and transmit on different pins than MDI-X. End devices use an MDI pinout and expect to connect to a hub or switch which use MDI-X. If end devices were the same as switches, you would have to use crossover cables for them but this way you only need them for hub to hub connections.<BR /><BR />BTW, most newer switches and hubs now have Auto-MDI meaning that they will do the crossover internally negating the need for crossover cables. Also be advised that gig ethernet uses all the pairs.<BR /><BR />See the pinouts for 10/100 at <A href="http://www.cabletron.com/support/techtips/tk0231-9.html" target="_blank">http://www.cabletron.com/support/techtips/tk0231-9.html</A> but you should be able to google for a better answer than I can provide.<BR /><BR /> Mon, 03 Jan 2005 08:51:04 GMT https://community.hpe.com/t5/switches-hubs-and-modems/networking-basic-question/m-p/3454015#M4321 Les Ligetfalvy 2005-01-03T08:51:04Z