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Possible Duplicate:
How do I know if my serial adapter card is working?

I'm not quite sure if I worded the title correctly, but here's my issue: I want to connect to a heavy duty Cisco router (not quite sure what model, but its an older one) using a USB to serial adapter on my Linux netbook. The netbook has a few USB 2.0 ports and a 10/100 Ethernet port.

I plugged the adapter in, loaded the modules for it, opened up putty, configured the baud rate, flow control, told it to use /dev/ttyUSB0, etc... pressed connect, and .......... nothing. I found a thing saying to use "sudo screen /dev/ttyUSB0" but that didn't do squat. I even tried a total shot in the dark by plugging the rollover cable directly into my RJ-45 port and sending the putty connection through eth0 (though I was posative that wasn't going to work, and it didnt).

Any ideas to get my Linux book connected to the cisco routers?

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marked as duplicate by izx, John S Gruber, Jorge Castro, Jjed, stephenmyall Aug 25 '12 at 15:55

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

Can you connect to the router from any other OS or system, using a USB-to-serial adapter? – izx Aug 22 '12 at 5:41
Yeah, a fellow student connects to the same router with an adapter on his Windows 7 laptop. – Cygnus X Aug 22 '12 at 14:00
Can you ask him for the settings...baud, parity, etc.? – izx Aug 22 '12 at 14:01
Already did, I have all of the settings correct. It just seems to be an issue with how Linux uses at the adapter. – Cygnus X Aug 23 '12 at 16:47
Also see… – belacqua Aug 25 '12 at 0:26

I have used several different laptops and serial adapters to connect to Cisco devices. I typically use minicom to connect -- you might try that. It is available from the software center, or you can use sudo apt-get install minicom. (If you do use minicom, use Ctrl-A and Z to access options -- check the speed and serial settings. Everything else tends to be correct.)

And /dev/ttyUSB0 is most likely correct if you're using a USB to Serial adapter.

Rollover to RJ-45 will not work, as you suspected.

If things still do not work, look for a different serial adapter -- I've been through several that work fine in Linux, but I suppose it's possible you might have gotten one that needs drivers that are not easily loadable under Ubuntu/Linux.

Borrow your friend's adapter if you can, and you can rule out your adapter that way.

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Got one that supports Linux kernel 2.4 and above. Run putty (or whatever terminal program you prefer) as root and BAM! it works. – Cygnus X Sep 7 '12 at 16:32

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