Clock Set Question

Answered Question
Feb 7th, 2009

Don't let the user name fool you. I'm a moron.

Can someone tell me how to set the clock rate on a cisco router for the serial port? Please help. I'm new to Cisco Routers.

Correct Answer by marikakis about 8 years 2 weeks ago

Hello Edward,

1. Nobody knows something before he/she actually learns it. Calling yourself names won't help to set the clock rate, so try to be more positive :-)

2. As Paolo suggested, you should determine if setting the clock rate is actually required on your side.

3. If you are connected to a provider, the provider normally supplies the clock.

4. If you are trying to set up some lab and you want to connect 2 routers back-to-back you could have a look at this document:

http://www.cisco.com/en/US/tech/tk713/tk237/technologies_configuration_example09186a0080094a3b.shtml

As it is stated there, "router connected to the DCE cable must provide clocking" (one side is DTE and the other is DCE).

5. You can use the "show controllers serial" command to check what kind of cable is attached to your interface and if you are receiving clock (search the output for phrases like: "DTE cable attached", "DCE cable attached", "received clockrate").

Kind Regards,

M.

p.s. Nice seeing you around again Paolo!

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Paolo Bevilacqua Sat, 02/07/2009 - 08:03

You can do this only when you act as DCE. On wan circuits, clock is almost always off circuit. Then it's a clock command under interface.

If you get a beginner text on routers and datacomms, all this stuff is there.

Correct Answer
marikakis Sat, 02/07/2009 - 09:31

Hello Edward,

1. Nobody knows something before he/she actually learns it. Calling yourself names won't help to set the clock rate, so try to be more positive :-)

2. As Paolo suggested, you should determine if setting the clock rate is actually required on your side.

3. If you are connected to a provider, the provider normally supplies the clock.

4. If you are trying to set up some lab and you want to connect 2 routers back-to-back you could have a look at this document:

http://www.cisco.com/en/US/tech/tk713/tk237/technologies_configuration_example09186a0080094a3b.shtml

As it is stated there, "router connected to the DCE cable must provide clocking" (one side is DTE and the other is DCE).

5. You can use the "show controllers serial" command to check what kind of cable is attached to your interface and if you are receiving clock (search the output for phrases like: "DTE cable attached", "DCE cable attached", "received clockrate").

Kind Regards,

M.

p.s. Nice seeing you around again Paolo!

ciscochief2999 Sat, 02/07/2009 - 12:57

Marikakis:

The document was Awesome!

Your encouragement and detailed explanation have enabled me to proceed successfully.

Thank you for volunteering your invaluable expertise and time to a novice in this new complex world.

marikakis Sat, 02/07/2009 - 14:55

Edward,

It seems you are a fast learner in all respects :-) There is plenty of documentation freely available at the cisco website, which will be more understandable as you progress. Try to use the search facility, and in any case, there are many volunteers in various sections of NetPro that can help you with any questions you might still have.

Kind Regards,

M.

Mohamed Sobair Sat, 02/07/2009 - 09:46

Edward,

Although Paolo & Maria have given u answers,But If Iwere a cisco moderator I wouldnt allow ur question to be posted, not because of the question it self.

I think u need to retype ur question properly.

HTH

Mohamed

marikakis Sat, 02/07/2009 - 10:27

Mohamed,

I think I understand what you mean, but the original poster is new to this forum and probably has not realized yet that here we try to keep our posts courteous (unlike much of the rest of the internet). I supposed we could cut some slack.

Kind Regards,

M.

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