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Morning Ok i missunderstod you and yestarday was not really my day. I hope you accept my excuse. Yes the postfix server works, I tested it with other VPN connections and large Mails so it cannot be the a problem of the postfix server. I also checked the transfer of files to the fileserver. Maybe its really a problem with the Memory of the M0n0 or the FlashCard, hope it works with a new one. And the last option is the MTU story.. I will keep you up-to-date.... Neil A. Hillard schrieb: > Jeff, > > In message <4523CF99 dot 1050406 at buehlertech dot com>, Jeff Buehler > <jeff at buehlertech dot com> writes > >>I think Neil is just saying it may be worth exploring other possible >>reasons for the email to be failing rather than focusing on the bad TCP >>checksums, which may or may not be related (is that right, Neil?). It >>seems to me that that woulds be a indication of part of the problem, >>though, but it may confuse the issue. For example, are you certain >>that the Postfix server doesn't have problems with large emails in >>general? I was having an issue with a mail server that had memory >>corruption due to memory timings in the bios that ONLY failed on very >>large email transfers (over 1.5 meg) and it took me quite a while to >>discover the cause, or even the problem, since none of my users >>reported it for a very long time. >> >>If it were me, I would try sending large emails from other locations to >>verify the server is functioning properly (just to discount that as a >>possibility), then I would try sending large files from the M0n0 VPN >>via FTP to see if the failure is specific to SMTP. I would suspect >>memory on the M0n0, or the network card. I have found with M0n0wall >>that using IPSEC changing the type of compression makes a difference >>with MTU issues (PPTP doesn't have that option). Finally messing with >>MTU settings is the only thing left, and I have had very significant >>problems that were hard to correct with MTU (just changing this and >>that didn't work - it required very deliberate changes on a number of >>systems along with reboots in some cases) running M0n0wall to Windows >>systems specifically. > > > Yep. My point was that the bad checksums may just lead you down the > wrong path and waste your time. > > To confirm whether this is a problem or is just TCP offloading, perform > a packet capture using a separate machine, either in a tap, a spanned > port on a manageable switch or a hub. > > At least that way you'll know if this really is a problem. > > HTH, > > > Neil. > > >>Andreas Ferrari wrote: >> >>>>This is probably a red herring. >>> >>>Thanks for your answer.... >>> >>>Dou you think i will report something that i have dreamd? >>> >>>The fact is that it still not working, I tried lowering the mtu >>>without sucess... >>>So if you or someone have any ideas what there could be wrong please >>>give me a hint. >>> >>>Neil A. Hillard schrieb: >>> >>>>Hi, >>>> >>>> I've been away for a while and haven't seen a response to this >>>>but apologies if I've missed it. >>>> >>>>In message <451A397A dot 8010006 at stasoft dot ch>, Andreas Ferrari >>>><aferrari at stasoft dot ch> writes >>>> >>>> >>>>>One of our customer has a VPN from his home office (wrap+m0n0 ver 1.22) >>>>>to his office (wrap+m0n0 ver 1.22), that works fine. When he tries to >>>>>send a mail from home over the VPN to the postfix server then the mail >>>>>is never delivered to the mailserver. >>>>>I noticed that small plaintext messages can be delivered to the postfix >>>>>server but if the mail gets bigger then only the first part of the data >>>>>are sent. >>>>>On the mailserver i started tcpdump and could see that the mail could >>>>>not be sent because there are a lot of bad tcp cksum messages. >>>>>So the mailserver gets the first part right and the rest of the data >>>>>are bad. How could that happend? >>>> >>>> >>>>This is probably a red herring. I suspect that you'll find that this is >>>>due to TCP Checksum Offloading. I spent a couple of days chasing what I >>>>thought were problems cause by this - turns out it was something else. >>>> >>>>HTH, >>>> >>>> >>>> Neil. >>>> >>> >>> >> >>--------------------------------------------------------------------- >>To unsubscribe, e-mail: m0n0wall dash unsubscribe at lists dot m0n0 dot ch >>For additional commands, e-mail: m0n0wall dash help at lists dot m0n0 dot ch >> > > -- STASOFT AG P: +41 61 726 80 70 F: +41 61 726 80 79 |