Bug 37392 - Machines hangs on boot
Summary: Machines hangs on boot
Alias: None
Product: Red Hat Linux
Classification: Retired
Component: ppp   
(Show other bugs)
Version: 7.1
Hardware: i386
OS: Linux
Target Milestone: ---
Assignee: Thomas Woerner
QA Contact: Aaron Brown
Depends On:
TreeView+ depends on / blocked
Reported: 2001-04-24 13:39 UTC by andrew.shaw
Modified: 2007-04-18 16:32 UTC (History)
2 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of:
Last Closed: 2004-08-13 09:25:24 UTC
Type: ---
Regression: ---
Mount Type: ---
Documentation: ---
Verified Versions:
Category: ---
oVirt Team: ---
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: ---

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Description andrew.shaw 2001-04-24 13:39:55 UTC
From Bugzilla Helper:
User-Agent: Mozilla/4.0 (compatible; MSIE 5.01; Windows NT)

External USR 56K Modem.
Machine hangs indefinitely when trying to bring up the ppp0 interface when 
booting the machine

Reproducible: Always
Steps to Reproduce:
1. Install Operating System (Fresh install or upgrade from 7.0-respin)
2. Configure ppp0 using the Dialup Configuration Utility, such that ppp0 
starts with the machine.
3. Reboot the server and machine hangs.

Actual Results:  Machine hand during the boot sequence.


When I reset the machine boot single user, turn networking off and bring 
the machine up. Reconfigure the ppp0 connection not to boot with the 
system. Machine is ok and the same configuration can be used to connect to 
the internet and disconect manually, it just doesn't work automatically. 

Expected Results:  Machine should boot automatically, ppp0 should be 
brought up and the machine should dial the internet either immediately or 
as soon as a non local packet is sent.

This problem was encountered when I upgraded from 7.0 to 7.1.

I thought that maybe a fresh install would cure the problem, but after the 
necessary rebuild of the machine the same problem has occured.

I have had to install a slower machine with 7.0 and am using this whilst I 
try out more "permutations", but would like any assistance.

The strange thing is when you activate the connect by hand using the debug 
button in the Dialup Configuration Utility the connect works fine, so why 
hang on boot?

It worked fine in 7.0

Comment 1 misterb 2001-05-03 08:55:48 UTC
Interestingly enough, I am having this problem to, but I haven't migrated to 
7.1 yet (still on 7.0). I had been upgrading some packages, one of which is 
initscripts, and all of a sudden exactly as above is happening to me too. 

I suspect it is something to do with how the ppp0 interface is coming up.... 
it's in demand mode too.

If I attempt to ping through the interface from another machine on my network, 
the connection comes up, and then the server will continue to boot. Can't find 
much in my logs about this though... But it was first thing this morning, I've 
not had a proper look yet.... Should do tonight though.

Comment 2 Alan Cox 2001-06-10 12:57:28 UTC
I see a similar problem in 7.1 but the dialing is working, its just that if the
modem is off for example it spends forever trying to dial. The ppp dialing
should be in the background

Comment 3 misterb 2001-06-18 09:45:40 UTC
On mine, the modem is on, but it still seems to hang. There is no dialing, and 
the process doesn't appear to be in the background (since everything stops till 
this command completes).

Comment 4 gmelder 2001-09-07 18:35:38 UTC
Newbie here, but the problem is still listed as "new" and as i haven't seen a
solution for this posted anywhere, i'm submitting this in the hopes that other
people find this information helpful.

You can skip to the end if all you want to know is how to fix this on your
RH7.1 (SeaWolf) installation.

It's not really a pppd problem, but more of a scripting "oversight" that is not
necessarily isolated to the boot sequence. This can be verified by the fact that
the ppp dial-up link works fine after boot, and also by manually launching
"/etc/init.d/network start" to simulate activating ppp0 (and other interfaces)
on boot, thereby invoking the hang. One of the scripts that gets called during
the course of executing the init scripts for activating ppp0 at boot time (when
"ONBOOT=yes" in the /etc/sysconfig/network-scripts/ifcfg-ppp0 config file) can
be found here: "/etc/sysconfig/network-scripts/ifup-ppp"

After much tracing & debugging via breakpoints, i found that it was the last
command called by this script that was causing the hang. This line (by default)
looks like this:

exec /usr/sbin/pppd -detach $opts ${MODEMPORT} ${LINESPEED} \
    ipparam ${DEVNAME} linkname ${DEVNAME} call ${DEVNAME}\
    noauth \

the shell variable expansions looked something like this:

lock modem crtscts asyncmap 00000000 defaultroute usepeerdns user
myusernameformyisp remotename ppp0 demand ktune idle 600 holdoff 30 /dev/ttyS2
115200 ipparam ppp0 linkname ppp0 call ppp0 noauth

all of which were fine. I then tested the pppd call from bash which outputted:

local  IP address:
remote IP address:

and then hung, at which point i had to ctrl-c to get my prompt back.

However, the man page that (presumably) applies to the version of pppd shipped
with 7.1 specifies an "-updetach" option, but does not specify "-detach" as a
valid option for pppd. Furthermore, the man page indicates a "-nodetach" option
which "Without this option, if a serial device other than the terminal on the
standard input is specified, pppd will fork to become a background process."

Here's HOW TO FIX (or what worked on my setup):
As a privileged user (root), load the file
into your favorite editor and remove the "-detach" command line argument from
the exec call to pppd towards the end of the file. Save changes, try again, and
all should be well.

Alternatively, you can look at the "-updetach" option in the pppd man page if
you are so inclined to attempt to make it work with this option. I did not try
this myself, so you're on your own.

Do i get an honorary RHCE now? Beta-testers needed? >;^&#254

- gabriel
a.k.a. gmelder@centurytel.net

Comment 5 gmelder 2001-09-24 20:34:54 UTC
In addition to my proposed solution above, you may also need to do the

Locate the line in /etc/sysconfig/network-scripts/ifup-ppp that reads as:
exec /sbin/ppp-watch "${DEVICE}" "$@"
(this is line 17 on my installation)
and insert a # symbol at the beginning of that line to comment it out.

ppp-watch attempts to provide on-demand functionality for a ppp link.
Unfortunately, in this script, it only results in a contentious redundancy with
pppd's default behavior, which is to wait in the background anyway, like the
good little daemon that it is.

NEVER give up. LMK what results you all get.

- gabriel

Comment 6 misterb 2001-10-09 08:03:52 UTC
I've just had a chance to try all of this. It did indeed fix the problem, at 
least on my 7.0 install.

To re-iterate what the fix is:

comment out the ppp-watch line.
remove the -detach from the pppd line.

Comment 7 Thomas Woerner 2004-08-13 09:25:24 UTC
Please verify this with a newer version of Red Hat Enterprise Linux or Fedora
Core and reopen it against the new version if it still occurs.

Closing as "not a bug" for now.

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