Serial connection recieving continuous junk

I am trying to connect over a serial port to an HP AM867A switch (more broadly it is a Brocade 8gb SAN switch). I got the switch used so I am trying to perform password resets. The switch is running Fabric OS 7.2.0d.

The switch has an RJ-45 console port which is connected with a DB9 adapter to a computer running Ubuntu 16.10. I'm using both picocom and minicom. I tried both with 9600 8N1 no flow control and minicom with software flow control. With both emulators I recieve the data shown below (an "R" followed by unicode "medium shade").

R▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒▒

The only difference is that with picocom the screen continuously scrolls down and there are some interspered 6. With minicom the the first line fills up and then the last character continuously changes.

Thanks in advance for any suggestions and if I can get anymore data please ask!

chew socks

Posted 2017-07-01T21:46:38.240

Reputation: 334

That is definitely what it looks like the communications settings are incorrect. I would suggest staying at 8N1 and trying 1200, 2400, 9600, 19200, 38400, 57600, and 115.2k speeds. My guess is you are going to find one of them is going to work. – acejavelin – 2017-07-01T23:21:53.260

@acejavelin Thanks for the suggestion! While the lower speeds produced some of the more normal characters (rather than unicode) it was still just random and continuous output. – chew socks – 2017-07-02T01:50:19.797

Answers

I haven't seen that behaviour before. 9600 8N1 seems reasonable, at least those are the default settings for a Brocade 6510.

What happens if you power-off the switch? Does the terminal emulator continue to see output? If so I would suspect that some other service on the Ubuntu system is configured to use the same port e.g. a login or getty process, and this might be interfering with your communication to the Brocade. I don't have any Ubuntu systems here, but UNIX/Linux login/terminal sessions are typically configured via /etc/inittab.

Alternatively, Brocade have a setup tool called EZSwitchSetup (really) which uses Ethernet based communication to connect to their switches. However I think that this package requires a Windows client system to install onto. I'm not aware of any Linux based version.

Robb W.

Posted 2017-07-01T21:46:38.240

Reputation: 93

Thanks for the suggestion! The output stops as soon as I power it off, and restarts as soon as the power cord is connected. For reference I'm connecting through /dev/ttyS0.

I'll work on getting EZSwitchSetup (it looks like creating an account is a little involved) but their documentation says they have a Unix version too, that'll let me use EZSwitchSetup with the serial connection too. – chew socks – 2017-07-01T22:58:38.927

I just remembered I can check the firmware version (Fabric OS 7.2.0d) through telnet (although I can't login through it). – chew socks – 2017-07-01T23:01:28.187

According to the Internet, it seems Ubuntu serial interfaces are configured via files named: /etc/init/<tty_name>.conf. So you might want to check the corresponding file on your system. How did it go with EZSwitchSetup? – Robb W. – 2017-07-02T21:45:11.520