Re: [exim] Very bizzare Exim related problem

Dean Brooks wrote:
> On Thu, May 04, 2006 at 08:38:29AM -0700, Marc Perkel wrote:
>
>
>> The home network lives behind a LINKSYS WRT54G router that acts as a NAT
>> and I've set it to port forward specific ports including SMTP to the
>> Linux/Exim server. And everything had been working well untill about 2
>> weeks ago.
>>
>> Even though it's a secondary server it is continously bombarded with
>> spammers attempting to spam the 500 or so domains I filter for. So the
>> connection rate is high.
>>
>
> I'd take a good look at the Linksys as the source of the problem. That
> is a residential grade router and its NAT processing engine may not
> be able to handle a larger number of unique connections. If the router
> is running low on memory/workspace, it could cause severe packet loss
> like you are experiencing. It would also explain why shutting down Exim
> resolves the problem since that is the destination of those connections.
>
> One way to test this would be to hook up your Exim machine with one
> of your external IP addresses and bypass the Linksys completely (just
> as a temporary test). If the problems goes away, its time to buy
> a different type of router.
>
>
>
That's my working theory as well about the connection count, that it's
the number of connections that's doing it. I notice that if I shut down
Exim and then restart it that it takes a few minutes before I start
getting packet loss. It's not a new Linksys router either. I'm not sure
that I can put the Linux box outside the Linksys since this is a home
service and I have only one IP address. Why do you recommend as a more
powerful home router?

I just thought of something - I could limit the number of connections ....