on 10-14-2008 6:24 AM Ralph Angenendt spake the following: > Sean Carolan wrote: >> We have an issue with some customers who refuse to accept ICMP traffic >> to their mail servers. It seems that they have put Mordac, preventer >> of information services in charge of their firewall policy >> (http://en.wikipedia.org/wiki/List_of_minor_characters_in_Dilbert#Mordac). > > BUT ICMP IS BAD!!!!!¡¡¡¡¡ > >> My mail logs are showing that customers who specifically disallow ICMP >> traffic have many "Connection Reset" entries in our logs: >> >> Oct 14 08:00:50 mailsrv sendmail[2024]: m9ED0Yf5002021: >> to=<customername at customer.org>, delay=00:00:16, xdelay=00:00:16, >> mailer=esmtp, pri=42476, relay=mail.customer.org. [XX.XX.XX.XX], >> dsn=4.0.0, stat=Deferred: Connection reset by mail.customer.org. >> >> I have disabled pmtu discovery on our routers as well as on all our >> outbound mail servers. Is there anything else I can do on our side to >> help the situation? > > So you basically broke your internet connection because of stupid > customers? No, there isn't anything you can do on your side - especially > if you don't know how large their MTU is set (which you cannot discover, > as they forbid you to do so). So you can only hope that you get exactly > the same MTU as they have (and that there is nothing inbetween which has > a lower MTU). > > It is their problem. If they don't want to play by the rules, they > should have to sit out the problems they themselves created. > Sometimes you can't be so hard headed when you are dealing with customers. You usually are trying to get them to give money to YOU, not your competitor. If I told my customers that "It is your problem", I would no longer have customers to worry about! -- MailScanner is like deodorant... You hope everybody uses it, and you notice quickly if they don't!!!! -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 250 bytes Desc: OpenPGP digital signature URL: <http://lists.centos.org/pipermail/centos/attachments/20081014/f73c58c8/attachment-0005.sig>