[lug] Sudden pppd problem, Mayday!

[D. Stimits]

Elyse M. Grasso wrote:

> Monday evening I updated from the KRUD June release to the July disks 
> and also
> cleaned out a bunch of packages (mostly devel) to free up some space.
>
> Something in the ppp settings got broken. This is a major problem 
> because I'm
> at a customer site in Minneapolis where I HAVE to use ppp. (I have 
> broadband
> at my hotel).
>
> My laptop that came from the factory 2 years ago with Linux only 
> installed, is
> now a dual boot machine: Windows has no problem connecting.
>
> I have backups of the old settings on an external drive in Colorado, 
> but that
> doesn't help much here.
>
> Reloading a partition with a clean RedHat 9 install and trying to set 
> up ppp
> through either kpppd or redhat-network-device-control results in the same
> problems I started seeing after the upgrade.
>
> kpppd makes the connection but fails with messages like
> Aug  8 06:30:36 xerxes pppd[3853]: pppd 2.4.1 started by root, uid 0
> Aug  8 06:30:36 xerxes pppd[3853]: Using interface ppp0
> Aug  8 06:30:36 xerxes pppd[3853]: Connect: ppp0 <--> /dev/ttyS1
> Aug  8 06:31:06 xerxes pppd[3853]: Terminating on signal 15.
> Aug  8 06:31:12 xerxes pppd[3853]: Connection terminated.
> Aug  8 06:31:12 xerxes pppd[3853]: Receive serial link is not 8-bit clean:
> Aug  8 06:31:12 xerxes pppd[3853]: Problem: all had bit 7 set to 0
> Aug  8 06:31:12 xerxes pppd[3853]: Exit.
>
> the messages log was complaining that modprobe could not find ppp0, so 
> after
> googling I aliased ppp0 to ppp_generic and that problem went away: the
> messages log now looks like:
> Aug  8 06:30:36 xerxes pppd[3853]: pppd 2.4.1 started by root, uid 0
> Aug  8 06:30:36 xerxes pppd[3853]: Using interface ppp0
> Aug  8 06:30:36 xerxes pppd[3853]: Connect: ppp0 <--> /dev/ttyS1
> Aug  8 06:30:36 xerxes /etc/hotplug/net.agent: assuming ppp0 is already up
> Aug  8 06:31:06 xerxes pppd[3853]: Terminating on signal 15.
> Aug  8 06:31:12 xerxes pppd[3853]: Connection terminated.
> Aug  8 06:31:12 xerxes pppd[3853]: Receive serial link is not 8-bit clean:
> Aug  8 06:31:12 xerxes pppd[3853]: Problem: all had bit 7 set to 0
> Aug  8 06:31:12 xerxes pppd[3853]: Exit.
>
...

It has been a long time since dealt with serial port issues, but in the 
past I had cured the "not 8-bit clean" stuff via setserial. It seems the 
serial port can have its settings changed very easily by a number of 
things. If you run "setserial -a /dev/ttyS1", you will see the serial 
port settings. Two flags that you might need are "spd_normal skip_test", 
and a manually set UART of 16550A. Basically, use setserial to view the 
serial port settings, and then use setserial again to repeat these 
settings while adding spd_normal, skip_test, and a uart of 16550A (it 
might not be a 16550A, but that is pretty darn rare). If this works, you 
can either add it to a hotplug script, or to the rc.local file.

D. Stimits, stimits AT comcast DOT net