🚀 go-pugleaf

John Phillips (john@linux.demon.co.uk) wrote:
: I have observed that my pppd shuts down at a random interval from 
: about 3 minutes to about 20 minutes after traffic ceases.  This 
: is with Linux kernel 1.1.47 and pppd from ppp-2.1.2a.


: I have not seen anything in the pppd manpage to say why this can 
: happen, so can anyone comment on what I might be doing wrong?

: The /var/adm/messages log shows:

: Sep 24 09:06:21 linux pppd[1698]: remote IP address 158.152.251.194
: Sep 24 09:17:17 linux pppd[1698]: Hangup (SIGHUP)
: Sep 24 09:17:17 linux pppd[1698]: ipcp: down
: Sep 24 09:17:17 linux pppd[1698]: Exit.

: When there is plenty of traffic, this does not happen.  I have run 
: over two hours of continuous traffic successfully in testing.

: If I set "lcp-echo-interval 180", even though the peer does not seem 
: to return the echos, this problem goes away, but I don't understand 
: why.

I had a similar problem on my system.  What seems to happen is that first of
all your service provider has some timer running on his end and after a
certain period during which no packets travel over the link it simply shuts
the connection down.  In my case it happens after 180sec from the initial
connection.

As far as lcp-echo stuff is concerned it will not work unless whoever you
dial up to has the echo request enabled on their end so that their server
responds to your requests.  Again for me it doesnt work either.

: Also if I then set "lcp-echo-failure 3", as expected, pppd shuts down 
: communications after the specified number of failed echos, but the 
: pppd process does not exit and the modem remains connected.  Moreover 
: pppd will not then exit on any signal but SIGKILL, so my normal ppp 
: shutdown script is ineffective.

Thats weird.  I had stuff like that happen when pppd received HUP and then
went down.  The modem should disconnect within some (unspecified) time
interval.  Sometimes for me it was quick sometimes it was slow.  The way
I worked around it is simply to runn your ppp-off script which should kill 
the deamon and all the rest of the stuff associated with it.

: The random hangup occurs when I start up pppd with:

: # Start the main PPP connection (machine name from /etc/hosts).
: /usr/lib/ppp/pppd connect /usr/local/sbin/demon.ppp \
:     debug \
:     crtscts modem defaultroute lock asyncmap 0x00000000 mru 576 mtu 576 \
:     /dev/$port 38400

Here you might want to look at your demon.ppp file.  I had problems setting my
chat script up initially.  Sometimes too many returns in the file cased the
modem to dial and then once the connection was up everything went to hell.

Also make sure you need asyncmap.  I though I did too in the begining but it turned out I didnt and it was only screwing things up.


As far as keeping the connection up try using some command that periodically
sends something over a link.  vmstat or ping will do.  They dont add too much
traffic to the link and make the connection stay up.

The longest I had the connection up with a ping was about 2 days after which
the noise on my phone like couse the whole think to collapse.

We now really need dial-on-demand.  Check out dp-2.3 sources at Perdue for
their deamon.  It is supposedly much better then pppd.  The only problem is
that there is no linux port.

-Kapi
-- 
Kapi, 542 Baldy Hall, 645-2448