COM connection, cant access prompt but am getting monitor feedback

[Will M]

I'm still learning and have a small lab at work to play with consisting of 2x 3750 48 ports and a 3750 with 24ports.

I know the com connection did work as thats how I initially set it up about 4 months ago, but I haven't used it much in the last 3 months and when I did I accessed via IP/ethernet.

So the ethernet connections are still fine however when I connect via com port its not allowing me to interact with it anymore.

I tried Putty and SecureCRT and behavior is the same. I get a blank screen with blinking cursor. I hit enter, ctrl-shift-6, nothing.

If I unplug or connect a wire I will get the monitor feedback of the line going up and down, so I am connected.

I get the same behavior across all 3 switches, and rebooted the first one, etc.

This leads me to believe its my local machine somehow. Any ideas where I should go to look?

I know if I try and open Putty when already connected via SecureCRT I get an error that the com ports in use. So i dont think it's another app having it in use, as I dont know any other programs I have installed that would utilize the com port.

[Mark Malone]

hi on your pc go to my computer -  manage- device manager- and ports section , when you connect your cable it  to will show up there as certain com port , make sure on putty is set to that com port , they can change , its unlikely all your devices as you said

[Will M]

Im on a desktop with a built in COM port, so device manager is showing Communications Port (COM1)

There is an Intelk Active Management SOL (COM3)

And 2 RIM Virtual COM4 and 5 I'm guessing from Blackberry software.

I tried a session with Com3 and I'm not even getting to link up/down messages.

I've also tried 2 different cables rj45-db9

[Mark Malone]

Have you tried a spare laptop or another device locally incase your com port has gone to rule it out ? at least that way you can be sure its not cabling ort anything else causing it

Try this to clear the com ports if there in use

http://superuser.com/questions/408976/how-do-i-clean-up-com-ports-in-use

[Richard Burts]

If I am understanding the post correctly he is getting console output of syslog messages which tells me that the com port is correct etc and that he has a correct connection to the switch but that he is not able to get a prompt or to enter commands. I have seen behavior like this when someone has configure line console 0 and then no exec (frequently trying to do an abbreviation of no exec-timeout). If the Ethernet/IP access is still working I suggest that you login to the switch that way and post the complete configuration of the console.

HTH

Rick

[Will M]

I reset the console 0 setting and didnt seem to make a difference,

line con 0
 exec-timeout 0 0
line vty 0 4
 exec-timeout 240 0
 password 7 xxxx
 logging synchronous
 login
 history size 100
line vty 5 15
 exec-timeout 240 0
 password 7 xxxx
 logging synchronous
 login
 history size 100

The other switch has,

line con 0
 exec-timeout 60 0
 logging synchronous
 history size 100
line vty 0 4
 exec-timeout 240 0
 password 7 xxxx
 logging synchronous
 login
 history size 100
line vty 5 15
 exec-timeout 240 0
 password 7 xxxx
 logging synchronous
 login
 history size 100

3rd switch is the same.

I just noticed the 2nd switch has some odd information coming back when i keep disconnect/reconnecting a test laptop.

26w6d: %LINK-3-UPDOWN: Interface FastEthernet1/0/9, changed state to up
26w6d: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet1/0/9, changed state to up
Switch2>Switch2>Switch2>% Inva
26w6d: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet1/0/9, changed state to down
26w6d: %LINK-3-UPDOWN: Interface FastEthernet1/0/9, changed state to down
Switch2>Switch2>Switch2>% Inva
26w6d: %LINK-3-UPDOWN: Interface FastEthernet1/0/9, changed state to up
26w6d: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet1/0/9, changed state to up
Switch2>Switch2>Switch2>% Inva

Switch 1 shows this,

21:57:34: %LINK-3-UPDOWN: Interface FastEthernet1/0/7, changed state to up
21:57:35: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet1/0/7, changed state to up
21:57:41: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet1/0/7, changed state to down
21:57:42: %LINK-3-UPDOWN: Interface FastEthernet1/0/7, changed state to down
21:57:44: %LINK-3-UPDOWN: Interface FastEthernet1/0/7, changed state to up
21:57:45: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet1/0/7, changed state to up

3 shows,

26w6d: %LINK-3-UPDOWN: Interface GigabitEthernet1/0/7, changed state to up
26w6d: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet1/0/7, changed state to up
26w6d: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet1/0/7, changed state to down
26w6d: %LINK-3-UPDOWN: Interface GigabitEthernet1/0/7, changed state to down
26w6d: %LINK-3-UPDOWN: Interface GigabitEthernet1/0/7, changed state to up

So com is partially working.

I had these running as you see for about 27 weeks and left that console cable in and hadn't modified anything else that I am aware of.

[Richard Burts]

The prompt that you are getting on switch 2 is quite interesting

Switch2>Switch2>Switch2>% Inva

But I am not sure what it might be telling us. This is just a simple connection from the com port of the PC to the console of the switch? Not through some type of terminal server?

Are these switches all stand alone switches or is there some type of stacking going on?

Perhaps the output of show line from the switches might shed some light?

HTH

Rick

[pwwiddicombe]

Within the terminal emulator, try disabling handshaking, and have flow control disabled.  It's possible your serial port is looking for CTS or DSR, which is normally handled in the blue Cisco rollover cable...

[Will M]

That switch isn't throwing that error anymore.

There isn't any stacking, I just have them connected via fiber, a to b&c, b to a&c, c to a&b.

I had gotten some usb adapters as we needed a few since none of our laptops have serial anymore and it didnt seem practical to carry a desktop into the room and remote into it just for that.

These are working fine, so it seems to me my onboard com port just isn't sending anymore. It appears to receive just fine.

I'll worry about that another day.

[pwwiddicombe]

I have seen this behavior on a laptop with docking station.  The docking station port works normally if the PC is powered up IN the docking station, but not if later plugged into the docking station and brought out of hibernation...  ?  In that case, same as you have seen, with input working, but no serial data in the computer-to-cisco direction.