Frequent loss of contact with ISP

[Gary Smithe]

On Thu, 24 Mar 2005 19:12:31 +0000, Ned Harrison <ned.woody at cox.net> wrote:
> 
> 
> ----------  Forwarded Message  ----------
> 
> Subject: Re: Frequent loss of contact with ISP
> Date: Tuesday 22 March 2005 01:15 pm
> From: Bill Moran <wmoran at potentialtech.com>
> To: Ned Harrison <ned.woody at cox.net>
> Cc:
> 
> [My apologies to the moderator for the traffic, but I just unsubscribed, and
>  I didn't want to leave this person hanging.]
> 
> Ned Harrison <ned.woody at cox.net> wrote:
> > On Sunday 20 March 2005 09:55 pm, you wrote:
> > > Ned Harrison <ned.woody at cox.net> wrote:
> > > > I reciently upgraded my home computer to FreeBSD 5.3 p5.  Sense then
> > > > I've had minor problems connecting to my ISP.  During boot up it will
> > > > sometimes freeze at the line, "Configuring syscons: keymap blanktime."
> > > > or I'll lose contact with my ISP while sending an email or surfing the
> > > > web. From an earlier posting to this forum I found that "Ctrl+C" will
> > > > let the system finishing the boot up.  Then I can easily connect to my
> > > > ISP by running "/etc/netstart" as root.
> > > >
> > > > Everything works fine at least for a while.  However, sooner or later
> > > > I'll lose the conection again.  I have not been able to discern a
> > > > pattern to the disconnects either.  Yet as soon as I run netstart again
> > > > everything works again.  It can be hours before I the lose the
> > > > connection or sometimes I'll lose the connection again within twenty
> > > > minutes.   I've searched for a permanent fix by looking throught this
> > > > forum.  But I havn't found anything yet.  Though that might be because
> > > > I don't quite know how to search! :-)
> > > >
> > > > I am a newbie using FreeBSD so any suggestions would be appreciated.
> > >
> > > Spend a little time in the /var/log directory and see if anything is
> > > being logged around the time you lose connection.
> > >
> > > Also, more clearly defining "lose connection" would help.  What does
> > > ifconfig say when the connection is up and when it's down?  The
> > > difference between those two outputs may lead you toward a solution.
> >
> > Thank you for the suggestions.  I've scanned the log files and didn't see
> > any unusual error messages.  But that could be because I don't know what to
> > look for.  I've run FreeBSD for just about one year and had no Unix
> > experience prior to that at all.  I jumped from Windows, where somebody did
> > everything for me to, FreeBSD where I have to figure things out on my own
> > with only hints and suggestions. (Honestly, I find it funner this way!)
> > I'll check to logs next time it goes down.
> >
> > I copied the results from ifconfig when everything is working to a file.
> > As soon as I "lose the connection" I'll run ifconfig again.
> >
> > To get more defined regarding the loss of connection, it's almost as if I
> > typed "ipfw flush" as root and cut myself down to the default "deny
> > everything" rule.  Sent emails will set unprocessed in the queue, when
> > attempting to download e-mail, K-mail will return an unknown host error
> > message,  web browsers will either open to a blank white page or give me an
> > invalid ULR error message.  It even went down while viewing a video on
> > Xine. The video just stopped, then I got an "invalid host" error message.
> > As soon as I type /etc/netstart.  Boom! everythings up an running as if
> > nothing was ever wrong.
> 
> I saw your other email as well, which shows that ifconfig during up/down is
> the same.  That means that you're not losing your IP address, and the fact
> that /etc/netstart fixes the problem probably means it's not hardware
> related.
> 
> So the next steps are to tear apart the networking system and figure out
> exactly which part of it is shutting off.  First, do these:
> 
> 1) Copy /etc/resolv.conf to your home dir: this contains your DNS
>    server information.
> 2) Save the output of `netstat -rn` (use something like
>    `netstat -rn > /home/<username>/netstat.txt`  This is your routing
>    table.
> 
> Now ... the next time it goes down, check:
> 1) Did /etc/resolv.conf change?
> 2) Did the output of `netstat -rn` change?
> 3) In the netstat output will be a line that starts with "default", see
>    if you can ping that IP address - if not, then the problem is probably
>    with your switch/hub or other local network.
> 4) Try pinging 206.190.36.122 (that's the ip for story.news.yahoo.com),
>    if it works, then the problem is likely with DNS.
> 5) if #4 works, try pinging story.news.yahoo.com ... if that fails, then
>    DNS is almost certainly the problem, if that works, then the problem
>    is somewhere in the network config, or application config.
> 
> --
> Bill Moran
> Potential Technologies
> http://www.potentialtech.com
> 
> -------------------------------------------------------
> 
> Thanks for the help.  I believe you are correct in that it's probably not a
> hardware issue.  I dual boot with Linux and I am having no problems
> connecting to the internet on that side.
> 
> System didn't go down Wednesday, but it went down today.  The output of
> netstat -rn didn't change.   I tried to ping the IP address after the word
> default in line 3.   Here is the output:
> 
> nedsbsd# ping -a -c 3 -o 68.13.118.1
> PING 68.13.118.1 (68.13.118.1): 56 data bytes
> ping: sendto: Permission denied
> ping: sendto: Permission denied
> ping: sendto: Permission denied
>


That looks like a misconfigured firewall.  Do you have it completely
locked down?  ping is telling you "I can't do that"



> --- 68.13.118.1 ping statistics ---
> 3 packets transmitted, 0 packets received, 100% packet loss
> 
> However, when I ran /etc/netstart and tried it again I got the same result.
> 



GS