Funny "C" character is all that appears on boot of 3600?

Answered Question
Apr 5th, 2007

When I power-on a 3640 Router with no adapters installed, all I see in Hyperterminal is a repeating "C" across the screen. What does this mean? I pulled this router from a storage room to see if it is working. It has two RAM and to FLASH SIMMs installed. I tried Ctrl+Break to go to ROMMON, but no luck. If I leave it, the characters eventually stop and nothing happens. Thanks.

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Correct Answer by Richard Burts about 9 years 9 months ago

James

Yes it is certainly possible that the speed of that particular router is set differently. That is what I was suggesting.

I found a link about the console speeds of the 3600 router which might be helpful. In the article is this:

you see that there are eight possible console baud rates, namely, 9600 (default), 4800, 1200, 2400, 19200, 38400, 57600, and 115200 baud. If you do not know the console speed of the router, it is difficult to set up a hyperterminal session with the correct speed. A solution would be to just try the eight possible console speeds above and see which one works.

If you want more details here is the link:

http://www.cisco.com/en/US/products/hw/routers/ps259/products_tech_note09186a008009433b.shtml

HTH

Rick

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Richard Burts Thu, 04/05/2007 - 10:48

James

That symptom sounds a bit like it might be a speed mismatch between the setting of the console speed and the speed set in your Hyperterm. I would suggest that you go through the various speeds supported and see if one works. It has been my experience with Hyperterm that when you change speed settings that you may need to stop and start Hyperterm to get it to recognize the changed speed.

HTH

Rick

jamesd058 Thu, 04/05/2007 - 11:10

OK, I'll try changing some speed settings. However, I am using Hyperterm to connect to other 3640's, 2600's, and 2950's right now. Is it possible the speed is set differently on the router? Will test and post back. Thanks.

Correct Answer
Richard Burts Thu, 04/05/2007 - 11:24

James

Yes it is certainly possible that the speed of that particular router is set differently. That is what I was suggesting.

I found a link about the console speeds of the 3600 router which might be helpful. In the article is this:

you see that there are eight possible console baud rates, namely, 9600 (default), 4800, 1200, 2400, 19200, 38400, 57600, and 115200 baud. If you do not know the console speed of the router, it is difficult to set up a hyperterminal session with the correct speed. A solution would be to just try the eight possible console speeds above and see which one works.

If you want more details here is the link:

http://www.cisco.com/en/US/products/hw/routers/ps259/products_tech_note09186a008009433b.shtml

HTH

Rick

jamesd058 Thu, 04/05/2007 - 12:06

Rick, 1200! Excellent. I'll read the link and see about setting it back to defaults. thanks to all who commented. Now a question... "If I set to 115200, and do an upload of an IOS bin file, will the speed actually be noticeably different than 9600?"

Thanks again all!

Richard Burts Thu, 04/05/2007 - 19:58

James

The answer to this question depends on what kind of upload you are doing. If you are doing the load using TFTP or FTP (or RCP) then the speed of the load depends on the interface speed and is not impacted by the speed of the console (which only would impact how quickly commands get to the router or impacts if you are doing cut and paste to get config info into the router).

But if you are doing xmodem to load an image then yes the speed of the load would be changed if you change the speed of the console.

HTH

Rick

jamesd058 Mon, 04/09/2007 - 03:25

Yes, definitely the Xmodem upload. I've done it before at 9600 and took a couple of hours. I'll try to test a 15 MB file upload at a couple different speed and post later in the week. Thanks.

PS. When I got into the startup-config I discovered there was a "speed 1200" command under "line con 0". Kept setting con to 1200 as well as a config register setting. Good experience to see this happen.

Richard Burts Mon, 04/09/2007 - 18:16

James

I do not believe that there is a console speed that makes xmodem a quick or pleasant experience. But if you increase the console speed to its max, I believe that you will notice a real difference in the performance of xmodem.

There are some models of routers that implemented the speed command on the console. And when they do it does over ride the config register setting (or keeps setting it back - I forget which) and the result is that you set the config register and the next time the router reloads you have a problem again. The real fix is to set the console speed in the config (or to remove the console speed command from the config and let the config register control the speed_.

Let us know what you observe in the performance speed of the various console speed settings.

HTH

Rick

Paolo Bevilacqua Thu, 04/05/2007 - 11:26

Yes, quite possibly the speed has been changed in the router, 19220 is the most likely. Unfortunately there is no way to reset it, you need to try them all until you can read text, then reset the configuration register that is what sets it. Long time ago I could have told you how the speed was set based on the strangeness of characters, but I have forgot now.

Hope this help, please rate this post using the scrollbox below!

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