This isn't quite true. For example, a DCE router interface will be down/down if DTR is not raised by the DTE device. I see this quite often at work and faulty cabling is generally not the culprit. It's almost always bad hardware in the DTE.
John Michael L. Williams wrote: > According to CCIE exam materials, the *only* time the serial will show > down/down is when there is NO serial cable or a bad serial cable connected. > So even if you have a misconfigured framing method, you should at least see > up/down..... > > Mike W. > > "Bob Timmons" wrote in message > [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > >>I can't say I've ever seen a down/up condition. Up/Down perhaps. >> >>I'm sure there are exceptions, but it's my belief that the router doesn't >>care about encoding, but rather a layer-1 connection to the dce/dte > > device. > >>If the router can 'talk' to the device on the other end of the cable, you >>should get an up/x condition, where x would depend on the csu/dsu > > condition > >>of the line. >> >>I don't have a csu handy, otherwise I'd check that right now. I can do > > that > >>tomorrow morning (10:30 pm est here), but you may have an answer prior to >>that... >> >> >> >>>Hi Priscilla, >>> >>>I have actually had this scenario (multiple times), but due to the >> > Telco's > >>>misconfiguration. >>>Specifically we were expecting b8zs/esf. Unfortunately I can't confirm >>>which was configured incorrectly, but I can confirm that going through >>>all of the different combinations available at the router you will >>>get all combinations on the serial interface (up/up, down/up and >> >>down/down). >> >>>I can also confirm, you will not establish connectivity, regardless. I >>>believe >>>either b8zs/esf or sf/ami are the only valid combinations. At least that >> >>is >> >>>all I've >>>ever worked with. >>> >>>Hope this helps, >>>-TV >>> >>> >>>""Priscilla Oppenheimer"" wrote in message >>>[EMAIL PROTECTED]">news:[EMAIL PROTECTED]... >>> >>>>Hi Group Study, >>>> >>>>While writing some questions for a practice test, I found myself >>>>questioning what I thought was the right answer. Here's the scenario: >>>> >>>>A Cisco router serial interface is correctly connected with a good >>> > V.35 > >>>>cable to the data port on the DSU side of a CSU/DSU. The CSU/DSU has >>> >>been >> >>>>misconfigured for the framing method (SF instead of ESF). The framing >>>>doesn't match what the provider is using. (The question refers to a >>> >>>CSU/DSU >>> >>>>that is external to the router, not one that is built into the >>> > router.) > >>>>Will the Cisco router serial interface be down/down or up/down? >>>> >>>>And, would the answer be any different if the question has to do with >>>>misconfiguring the encoding (AMI versus B8ZS)? >>>> >>>>If you have real-world experience with this, that would help. I have >>> >>read >> >>>>the Cisco documentation and the troubleshooting charts, etc. >>>> >>>>Thanks >>>> >>>>Priscilla >>>> >>>>________________________ >>>> >>>>Priscilla Oppenheimer >>>>http://www.priscilla.com Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=47119&t=47101 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
