Thank you, Thomas. Yes, I have the TX crossed to the RX, otherwise the error lights light up. Tom -- Tom Keough, CCNP MCSE CCIE Candidate [EMAIL PROTECTED] ""Thomas Larus"" wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > I think this would involve making sure that you plug the TX (SC or ST) plug > into the OC3 interface's RX jack (SC or ST) opening, and vice-versa. I > can't afford ATM for my lab, but I remember thinking it was neat that you > could do some basic ATM stuff without the switch. If you are asking for > some guidance at a more advanced level than this basic cabling level, then > forgive my post. > > Thomas Larus > ""Tom Keough"" wrote in message > [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > > Hello groupstudy, > > The problem is that when I configure and no shut the interfaces they just > > bounce between up and down every few seconds. I can put up a "loopback > > diagnostic" and ping each interface ok. I have connected a 3640 and a 2600 > > each with an ATM OC3 card back to back. I suspect I have not installed the > > two multimode fiber cables properly. I have searched CCO but can't find > > instructions for cabling the back to back configuration. I am using > Caslow's > > book for the ATM configuration. > > > > I just read in the ATM section of the All-In-One CCIE Lab Study Guide > about > > using one fiber cable for the back to back config vs. two cables to a > switch > > but which cable to which jack?? I won't have access to my lab again until > > Monday or I'd be cable swapping right now. > > > > If anyone has any info on this I would greatly appreciate hearing from > > you... > > TIA, > > Tom > > > > -- > > > > Tom Keough, CCNP MCSE > > CCIE Candidate > > [EMAIL PROTECTED] Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=20071&t=20071 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]