OT - Firewall suggestion

Steve Mason smlists at SHAW.CA
Thu Nov 11 18:49:20 GMT 2004


> Someone/thing has decided to circumvent the MX records
>and try the sendmail boxes directly.

>My firewall blocks all of this, so there is no worries there, but it sure is
>wasting a lot of bandwidth. I would like to hear any suggestions on what may
>have been done to slow this down, or any other nifty things that may help. I
>use IPTABLES as a firewall.

>Unfortunately, the gateways are outside the firewall, so they are being beat
>up pretty bad. I can't move these inside (not my decision). I also don't
>manage the gateways, so....

Unless I'm missing something, how would connection requests on port 25, being blocked by the firewall waste bandwidth?

One thing you can do to slow down the perpetrators, is use DROP instead of DENY or REJECT in your iptables for port 25, this will cause the system attempting the connection to wait for a timeout.


Steve

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