RE: [Sheflug] offline viewing

["darkstar" <nospam [at] btinternet.com>]

-----Original Message-----
From: sheflug-bounce@vuw.ac.nz [mailto:nospam [at] vuw.ac.nz]On
Behalf Of ross
Sent: 17 September 2000 20:11
To: Sheflug
Subject: [Sheflug] offline viewing

Original message read:
hi,

i've been trying to gonfigure offline and automated facilities for linux.
i've successfully configured the email side of things with sendmail and
fetchmail via diald and cron

but i'm running into problems with web pages :-(

i've packaged up my config files as several people have requested copies and
i'd like to do the same with off line web browsing. a few of my friends are
starting to use linux and this seems to help get over the hurdle of "well i
did
it with windows easily enough!".

the config i'm trying is to use squid as the proxy set to 'offline on' in
the
config file so as not to verify web pages when requested and so provide off
line viewing of the cache. i use diald to start up a ppp connection when
required.

the problem is that although this works some of the time, occationally it
fails. by this i mean that when using netscape to browse, and a NEW web page
is
requested, diald starts the connection but no packets are exchanged when
pppd
is running. all future attempts to connect meet with the same result......
i've
been running diald for some time now with no probs like this so i can't see
this
beeing the prob? the only way round the issue is to reboot. i've killed the
diald process and restarted, killed squid and netscape. when i run kppp and
try
to query the modem, it reports that the modem is busy.... this suggests that
some process is trying to access the modem? i can't find any lock files
causing this though........

i removed the firewall rules just in case but to no availe.

the only other aspect i have comsidered is the daild input buffer being full
of
requests.... if it did fill up it wouldn't see new requests and so not
attempt
to reconnect!?!? but i'm guessing :-)

if anyone has any advice on either rectifying this or on alternative methods
i'd appreciate it.............

--
Thanks,
        Ross
               ross.h [at] ntlworld.com

OK Ross,
	One thing comes to mind, and that is that when using dynamic ip addresses
the first packet gets lost coming back I think because the return address is
wrong due to your isp giving you a dynamic ip. This exerpt from one of the
mini-howto's sums it up. Perhaps it is partly the cause of your problem.

6.7 IP Masquerade and Dial-on-Demand Connections


If you would like to setup your network to automatically dial up the
Internet, ether the Diald demand dial-up or new versions of the PPPd
packages will be of great utility. Diald is the recommended solution due to
its more granular configuration.

To setup Diald, please check out the Setting Up Diald for Linux Page or
TrinityOS - Section 23

Once Diald and IP Masq have been setup properly, any MASQed client machines
that initiate a web, telnet or ftp session will make the Linux box
dynamically bring up its Internet link.

There is a timeout that will occur with the first connection. This is
inevitable if you are using analog modems. The time taken to establish the
modem link and the PPP connections may cause your client program (WWW
browser, etc.). This isn't common though. If this does happen, just retry
that Internet traffic request (say a WWW page) again and it should come up
fine. You can also try setting echo "1" > /proc/sys/net/ipv4/ip_dynaddr
kernel option to help with this initial setup.

I had a similar problem with a similar setup, mail exchange was fine but
when a machine on my network requested a page from the web, the proxy server
would dial out, but the request for data would time out. Hitting stop&reload
after the link had come up worked and everything was fine until the link
went down again (mine was set to close after 6mins idle). I never quite got
my setup finished in that you also have to restart the ipchains otherwise a
similar thing happens, no packets in from the net. There is an excellent
book Linux firewalls by Robert L.Zieger published by New Riders that
explains firewall rules and touches on dynamic ip address problems, but it
does assume your using RedHat.

Hope this helps to some extent,
Darkstar
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