Normally you connect to a switch and the switch provides the clock to the routers (external clock). Tom -- Tom Keough, CCNP, MCSE CCIE Candidate [EMAIL PROTECTED] ""Patrick Ramsey"" wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > I didn't see this question earlier...but I have a question concerning the > connectivity between these two devices... > > What is the difference in having these boxes in a lab environment and in the > field? (as far as clocking goes) > > If they're hooked up back to back, isn't that the same way you would have > them in the field? > > What happens when you switch clocking to internal? What does this > accomplish? Is this a cisco specific thing to configure atm through sonet > as opposed to dark fiber? (or vice versa) > > I've never had to do anything like this with any vendor's gear. Just > curious as to what is actually taking place here. > > -Patrick > > >>> "Tom Keough" 09/17/01 01:16PM >>> > Hello Groupstudy! > Thanks to those who spotted my clocking issue with connecting two ATM > routers back to back in my lab. The command "atm clock INTERNAL" (caps > supplied by Cisco IOS 12.x) instantly solved the problem of the bouncing > interfaces ATM1/0!! > You were my last resort to solve this problem and you came through like > champs... > Thanks and God Bless America, > Tom > -- > > Tom Keough, CCNP, MCSE > CCIE Candidate > [EMAIL PROTECTED] > > ""Daniel Cotts"" wrote in message > [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > > You need to have clocking internal on one end and line (default) on the > > other. > > atm clock INTERNAL > > I don't have Caslow handy so don't know if the above is included in the > > config. > > Here's a working config between two 7500s. They are running 11.3 > > > > First end: > > interface ATM6/0 > > description Location AnyCo_North. Always node 4. > > no ip address > > atm clock INTERNAL > > ! > > interface ATM6/0.1 multipoint > > description pvc to Data Center via fiber > > ip address xxx.yyy.7.250 255.255.255.252 secondary > > ip address 10.18.35.4 255.255.255.0 > > atm pvc 1 0 35 aal5snap > > map-group TGN > > appletalk cable-range 35-35 35.4 > > appletalk zone ATM > > map-list TGN > > ip 10.18.35.1 atm-vc 1 broadcast > > appletalk 35.1 atm-vc 1 broadcast > > ip xxx.yyy.7.249 atm-vc 1 broadcast > > > > Other end: > > interface ATM12/0 > > description Location AnyCo. Always node 1. > > no ip address > > ! > > interface ATM12/0.1 multipoint > > description pvc to AnyCo_North > > ip address xxx.yyy.7.249 255.255.255.252 secondary > > ip address 10.18.35.1 255.255.255.0 > > atm pvc 1 0 35 aal5snap > > map-group TGE > > appletalk cable-range 35-35 35.1 > > appletalk zone ATM > > > > map-list TGE > > ip 10.18.35.4 atm-vc 1 broadcast > > appletalk 35.4 atm-vc 1 broadcast > > ip xxx.yyy.7.250 atm-vc 1 broadcast > > > > > > > -----Original Message----- > > > From: Tom Keough [mailto:[EMAIL PROTECTED]] > > > Sent: Saturday, September 15, 2001 2:06 PM > > > To: [EMAIL PROTECTED] > > > Subject: Problem connecting 2 routers w/ATM OC3 int back to back > > > [7:20061] > > > > > > > > > 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] > > > Report misconduct > > > and Nondisclosure violations to [EMAIL PROTECTED] Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=20194&t=20194 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
