Re: [exim] synchronization error (input sent without waiting…

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Author: John Robinson
Date:  
To: oliverj
CC: Exim Users
Subject: Re: [exim] synchronization error (input sent without waiting for greeting) - question
On 14/11/2007 12:22, Oliver Howe wrote:
>
> I have two smtp servers that sit behind alteon load balancers which perform health checks every 5 seconds to make sure the servers are up.
>
> but these health checks are causing a lot of messages like this to appear in the log files
>
> 2007-11-14 12:18:17 SMTP protocol violation: synchronization error (input sent without waiting for greeting): rejected connection from H=[212.57.34.221]
> 2007-11-14 12:18:22 SMTP protocol violation: synchronization error (input sent without waiting for greeting): rejected connection from H=[212.57.34.220]
> 2007-11-14 12:18:23 SMTP protocol violation: synchronization error (input sent without waiting for greeting): rejected connection from H=[212.57.34.221]
> 2007-11-14 12:18:28 SMTP protocol violation: synchronization error (input sent without waiting for greeting): rejected connection from H=[212.57.34.220]
>
>
> what is the best way to avoid such messages?


It looks to me like the Alteon load balancers' "health check" is 
badly-behaved. You probably want to add something like the following to 
your connect ACL:
   warn hosts   = 212.57.34.220 : 212.57.34.221
        control = no_enforce_sync


Cheers,

John.