Re: pppd 2.2.0f strangeness

Jon Lewis (jlewis@inorganic5.fdt.net)
Tue, 18 Feb 1997 17:06:11 -0500 (EST)


Here's another data point. I just had _exactly_ the same thing happen on
our other terminal server with the _same_ user. He has logged in numerous
times without causing this problem though...so I don't think his client is
necessarily misconfigured. I've looked through our records, and this
person is a MAC user. I haven't been able to get him on the phone...so
that's all I know right now. Another thing I didn't notice last time (but
happened both times) is that ip-up was run apparently for each loop
iteration...i.e. I do some logging in ip-up, and it was run several times
a second while the pppd process was going wild.

This second terminal server is mostly identical except for the use of
Cyclades multiport cards rather than Comtrol.

On Sat, 15 Feb 1997, Jon Lewis wrote:

> Has anyone ever seen this sort of thing?
>
> Feb 15 09:17:55 endor pppd[3830]: pppd 2.2.0 started by riherd, uid 333
> Feb 15 09:17:55 endor pppd[3830]: Using interface ppp36
> Feb 15 09:17:55 endor pppd[3830]: Connect: ppp36 <--> /dev/ttyCh
> Feb 15 09:17:56 endor pppd[3830]: local IP address 205.229.48.4
> Feb 15 09:17:56 endor pppd[3830]: remote IP address 205.229.51.146
> Feb 15 09:17:56 endor pppd[3830]: local IP address 205.229.48.4
> Feb 15 09:17:56 endor pppd[3830]: remote IP address 205.229.51.146
>
> [this repeats _many_ times/s and then]
>
> Feb 15 09:18:10 endor pppd[3830]: local IP address 205.229.48.4
> Feb 15 09:18:10 endor pppd[3830]: remote IP address 205.229.51.146
> Feb 15 09:18:54 endor in.fingerd[4397]: connect from ewok.fdt.net
> Feb 15 09:18:46 endor kernel: Couldn't get a free page.....
> Feb 15 09:20:09 endor pppd[3776]: Hangup (SIGHUP)
> Feb 15 09:20:16 endor pppd[3776]: Modem hangup
> Feb 15 09:20:25 endor pppd[3776]: Connection terminated.
> Feb 15 09:20:28 endor pppd[3776]: Exit.
> Feb 15 09:18:10 endor pppd[3830]: local IP address 205.229.48.4
> Feb 15 09:18:10 endor pppd[3830]: remote IP address 205.229.51.146
>
> [more repetition clipped...then finally pppd seems to terminate]
>
> Feb 15 09:19:30 endor pppd[3830]: IPCP: timeout sending Config-Requests
>
> Note...it looks as if the system ran short on memory...I'm assuming the
> pppd process 3830 fell into some sort of "infinite" loop, terminated only
> when ipcp timed out, with a memory leak as a side affect. Look at the
> freelog (kept for historic reasons back when these boxes used to be pretty
> unstable)
>
> Here we are just before the problem. System is at half capacity portwise,
> plenty of RAM to spare, no load.
>
> 9:15am up 34 days, 19:08, 34 users, load average: 0.04, 0.07, 0.03
> total used free shared buffers cached
> Mem: 31012 30756 256 18700 2716 6572
> -/+ buffers: 21468 9544
> Swap: 61696 0 61696
>
> Here we are just after it...and that must have been a monster pppd process
> to have just released 17+mb of RAM...and look at that load avg!
>
> Sat Feb 15 09:20:30 EST 1997
> 9:20am up 34 days, 19:13, 34 users, load average: 96.34, 44.31, 16.85
> total used free shared buffers cached
> Mem: 31012 13528 17484 3012 196 1136
> -/+ buffers: 12196 18816
> Swap: 61696 9292 52404
>
> Shortly after this, the system returned to a normal state, and is still
> running. I suspect some of it is because I'm running an older syslogd
> that fsync's on every write...so that tight loop with the IP addresses
> being syslog'd must have really been a kick in the balls for the disk, not
> to mention all the swapping that happened. Time to upgrade some more
> systems.
>
> Kernel is 2.0.27, compiled ELF with gcc 2.7.2.1. pppd is a.out compiled
> with 2.6.3, libc 4.7.6. I've run a number of similar boxes for nearly 2
> years and never seen this happen.
>
> I just went looking for ppp-2.2.0g, and can't find it. It's not in the
> places I know to look, and ftp.sii.com looks as if Al may have left them.
> I'd hoped to check to see if this was perhaps a documented/fixed bug.

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