Bug ID 714986: Serial Console Baud Rate Loses Modified Values with New Logins on iSeries Platforms Without Reboot

Last Modified: Sep 10, 2019

Bug Tracker

Affected Product:  See more info
BIG-IP All(all modules)

Known Affected Versions:
12.1.0, 12.1.0 HF1, 12.1.0 HF2, 12.1.1, 12.1.1 HF1, 12.1.1 HF2, 12.1.2, 12.1.2 HF1, 12.1.2 HF2, 12.1.3, 12.1.3.1, 12.1.3.2, 12.1.3.3, 12.1.3.4, 12.1.3.5, 12.1.3.6, 12.1.3.7, 12.1.4, 13.0.0, 13.0.0 HF1, 13.0.0 HF2, 13.0.0 HF3, 13.0.1, 13.1.0, 13.1.0.1, 13.1.0.2, 13.1.0.3, 13.1.0.4, 13.1.0.5, 13.1.0.6, 13.1.0.7, 13.1.0.8, 13.1.1, 13.1.1.1, 13.1.1.2, 13.1.1.3, 13.1.1.4, 13.1.1.5, 13.1.3, 14.0.0, 14.0.0.1, 14.0.0.2, 14.0.0.3, 14.0.0.4, 14.0.0.5, 14.0.1

Fixed In:
14.1.0, 12.1.4.1

Opened: Apr 13, 2018
Severity: 3-Major

Symptoms

On an iSeries platform, when the console baud rate is changed through TMSH, new terminal sessions revert back to the previous baud rate instead of adopting the new setting unless the unit is rebooted.

Impact

The BIG-IP system reverts to the previous baud rate instead of the new setting. Inability to create any new serial console connections with the modified baud-rate without a reboot.

Conditions

1. Modify the console baud rate in BIG-IP through TMSH on an iSeries platform (i2xxx, i4xxx, i5xxx, i7xxx, i10xxx, i15xxx), for example: tmsh modify sys console baud-rate 9600. 2. Exit from the login prompt in the current terminal session, or kill it and start a new session.

Workaround

The problem can be mitigated by manually reprogramming the TTY device and restarting the agetty process and bash login sessions. This closes any existing console connections, but newly established connections will connect at the modified baud rate. 1. Use TMSH to modify the baud rate to the desired speed by running a command similar to the following: tmsh modify sys console baud-rate 9600 2. Re-program the TTY device with the desired speed by running a command similar to the following: stty -F /dev/ttyS0 9600 3. Kill the existing agetty process so it will re-start at the new baud rate by running the following command: /usr/bin/killall -q agetty 4. Restart bash logins by running the following command: /bin/kill -HUP `/bin/ps -A | /bin/grep ttyS0 | /bin/grep -v grep | /bin/grep bash | /bin/awk '{print $1}'` >/dev/null 2>&1

Fix Information

In addition to reprogramming the UART with the new baud rate, the BIG-IP system now re-initializes the TTY device and agetty process with the correct speed so that new terminal sessions reflect the change.

Behavior Change