Date: Sun, 22 Nov 1998 17:09:42 +0100 (CET) From: Marc van Woerkom <marc@netcologne.de> To: G.Sittig@abo.FreiePresse.DE Cc: freebsd-isdn@FreeBSD.ORG Subject: Re: isppp + dynamic IP Message-ID: <199811221609.RAA00533@oranje.my.domain> In-Reply-To: <Pine.LNX.4.02.9811221143241.25082-100000@speedy.gsinet> (message from Gerhard Sittig on Sun, 22 Nov 1998 11:55:25 %2B0100 (CET))
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> When the connection goes up > the ISDN interface has ANY address and sends out its first packet. > While negotiating with the ISP the interface CHANGES its address to > the newly assigned one and won't accept the answer for the first sent > packet (in addition the ISP won't even send this answer to THIS > interface since the dynamic address meanwhile belongs somewhere else). > Sending a second packet when the connection is up and configured > you get your answer. %&$!, you are right. And the network interface often changes its IP address several times, for I use an idle time of about 30s to minimi$e online time.. Sometimes I see the line going up again, without me doing a request. My guess is that this is some sort of control packet, by an older request of mine, that has not been completed (e.g. a lame ftp transfer), and that is now fooled because the IP at time of the request is different from the present IP now due to a hang up in between. Solution? For *incoming* packages, the network mechanism ought to keep a table of all IP addresses that were in use by the interface, routing packages with outdated addresses to the address in use now. I am not sure how to make the system work like this. Well, natd looks promising - is anyone familiar with it here? > i4l has a dynip patch which stores the first packet with the old > address which triggers dialing and resends it when the connection > is up (with the new address in the packet). What you are saying here, and I did not realize this before, is that my system could get difficulties with *outgoing* packages too when the interface plays chameleon. > In general one could assume that i4l and i4b should be the same > in many respects and there should be a great amount of common > code, or did I miss a point ? I don't know the commonalities regarding ISDN, but I tried to use interesting bits from an Linux audio driver and gave up for the infrastructure was too different. (Could be my fault :-) > Is there any DNS query "in front of" the data traffic ? Then the > DNS packets will experience the described effect and pop works fine. I suspect Netscape 4.5 doing sneaky communications with its mothership. That's why I put this ---------------------------------------------------------------------- 194.25.242.193 www-de.netscape.com home.netscape.com 194.25.242.194 www-de2.netscape.com home6.netscape.com 198.41.0.9 internic.net ---------------------------------------------------------------------- into my /etc/hosts - I don't want do pay my ISP only because I browse a local document. BTW - what is the easiest way to monitor an interface, at socket level? 'tcpdump' (the way I use it) produces way too much information, 'systat 1 -net' is a bit too transient. Regards, Marc To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-isdn" in the body of the message
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