Problem with serial console usb connection

captainjon

New Member


Messages: 6

I'm using an old laptop, it was running 10.3 i386 version only in terminal mode. I use it to connect make a serial connection from usb port (cu -l /dev/cuaU0 -s 115200 && screen) to a pfSense appliance.
The pfSense appliance runs freebsd and recently it was updated to v11.3. I don't use the serial console connection often, a few times a year, maybe.

Lately it is giving me gibberish when connecting so I thought perhaps there was an issue between my laptop running v10.3 and pfSense running 11.3. I decided to update my laptop. I updated to i386 version 11.0 release p16

Now when I make my usb serial connection (using cu and screen) I get the menu on pfSense but when I request a shell connection in pfSense I get "resizewin: timeout reading from terminal" and this continually loops until I remove the usb cable. My resolution is VGA/16. Any ideas why I get resizewin timeouts?
 

Phishfry

Son of Beastie

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I am seeing this too on serial to serial connections. This is using FreeBSD to cu into NanoBSD under ttyu0
So I don't have any answers for you but I do wonder if you are using pFSense NanoBSD version?
Perhaps it is something in NanoBSD that has been removed.
I just ignore it as it seems to have no effect on the OS for me. No looping just a one time message on bootup.
I did try and chase down the cause but did not get far.
 
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captainjon

New Member


Messages: 6

Keep going, 11.0 is End-of-Life and not supported any more. You need to upgrade to 11.4.

I know it's not supported but I need baby steps to get there. I'm at 11.0-STABLE and when I access my pfSense Netgate Built I get the above mentioned resizewin. I did go to 12 and had more issues so backleveled to 11. Once I solve this I can move on but 12 alone apparently does not solve my problem.
 
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captainjon

New Member


Messages: 6

It looks like you could simply switch to sc(4) on the host for this to be fixed.
You say "on the host". I presume by host you mean my pfSense box. That device is a Netgate Built device running on top of 11.3-STABLE, I did not build it so I will not manipulate the OS on that device. I'll call their support and see if they have a clue about this problem.

Thanks.
 
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captainjon

New Member


Messages: 6

pFSense NanoBSD version
Nope, I'm using a Netgate box, SG-5100. It was recently upgraded by them to 11.3-STABLE. I forget which version it was running prior to that upgrade but my laptop with 10.3 had no problem connecting to it. I assumed it may have to do with 10.3 using VGA/16 connecting to 11.3 (I don't know what resolution it is set for).
 
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captainjon

New Member


Messages: 6

I see that my replies are awaiting moderator approval. So here is more info on my problem.
pfSense operates as a headless device. I usually interact with it by accessing it via a web interface over my home network. My problem is with access via the provided serial console. This would be used as a failsafe backup to access the device which is my internet router & firewall.

I called the manuf (Netgate) and they said it's not at their end, probably at my end. Even when I stated that it worked fine in their prior config, it seemed (I'm not certain because I rarely use the serial access) that it started this problem after they released an update using 11.3-STABLE.

I am not proficient at freebsd and had to do a lot of reading just to do my update from 10.3->11.0. I will do more reading because apparently there are pkg's involved even tho I am not aware of any, except that sudo is one that I use (turns out I don't need that when accessing via a serial terminal window).

When I plug in the serial cable the procedure I use to access the pfSense menu is run the following:
sudo cu -l /dev/cuaU0 -s 115200 && screen
then I press Enter and I get the menu. A few notes: I can run this as root w/o sudo and today I found out it works without the screen command.

The menu provides, among other options, a shell command to the pfSense appliance system. This is the command that I found gives a looping error as stated at the start of this thread. Today I found out that if I wait long enough, it finally drops me into the shell. At that point I can do whatever it is I need to do but every command produces one instance of the error instead of a repeating error.

Yesterday, when I posted this thread I was spinning my wheels, getting nowhere. Now, understanding that I can allow the error to loop and eventually start working I will now start reading more about updating to the latest stable version that works on an i386 laptop in the hopes that this error goes away. The bug report mentioned upthread doesn't indicate that it got any attention. One comment by the last commentor in that bug report was "Presumably all that needs to be done to address this PR is to add a vt tf_respond."

I don't understand exactly what that comment means, it refers to teken which I don't know about and there is more info at github but that is beyond my current understanding.

I welcome any further advise but it appears that this is something that I'm just going to have to live with since I rarely use this serial terminal access and the error does not seem to be common.
 
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captainjon

New Member


Messages: 6

It looks like you could simply switch to sc(4) on the host for this to be fixed.
...snip...​
A persistent change is achieved in /boot/loader.conf
kern.vty="sc"
When I add this to the loader.conf and boot, my laptop displays ttyv0 on the line above the login prompt.
So either it is not sc or is it? How can I tell?

Assuming it is now using sc instead of vt, when I try to connect to my pfSense box I get escape characters when I enter commands.
Removing the sc from the loader brings it back to the original condition, the commands work and I still get the resizewin error.

Thanks for all the info so far, I've learned a lot. I will now proceed to bring my laptop up to 11.4
 

Phishfry

Son of Beastie

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Messages: 4,903

I attempted to fix this by changing to sc(4) and it had no effect. Still get the message on boot up.
I changed to sc(4) on both sides and still get the message.
So I give up. It is not a bother for me.
 
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