On Tue, 2015-06-09 at 15:45 +0530, soumya tr wrote:
> Hi,
>
> Any one have tips on preventing DoS attacks on port 25?
>
> --
> Regards,
> Soumya
You don't give much detail on what you are trying to achieve but at a
first stab have a look at the docs on these and other related settings:
smtp_accept_max
smtp_accept_max_nonmail
smtp_accept_max_nonmail_hosts
smtp_accept_max_per_connection
smtp_accept_max_per_host
smtp_accept_reserve
smtp_reserve_hosts
smtp_load_reserve
smtp_max_synprot_errors
smtp_max_unknown_commands
smtp_connect_backlog
smtp_enforce_sync
With careful tuning and careful thought about what they do you can rate
limit the vast majority of the outside world but still allow those
systems that simply must get through regardless.
You can also look into using your external firewall to to some limiting
as well.
Cheers
Jon
Blueloop Ltd
Jon Gerdes | Senior Consultant
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