Hundreds of error messages in log about closed port 11211

[Maxim Dounin]

Hello!

On Sat, Feb 16, 2008 at 11:48:53PM +0000, Ben Sebborn wrote:

> Hi
>
> I'm getting loads of these messages logged in FreeBSD (ive enabled 
> log_in_vain which logs all attempts to connect to a local closed port)
> *
> kernel: Connection attempt to TCP [::0001] 11211 from [::0001]:57097 flags: 
> 0x02*
>
> Note the MEMCACHED ports ---
> About 10 per second are being logged at least. I'm confused why this is 
> happening, as memcached is running and there are no firewalls on this host?
>
> If I telnet localhost 11211 I get the memcached daemon
>
> Any ideas? I'm a bit worrying as the console keeps telling me it's rate 
> limiting connections due to the above?

The message is for connection attempt to IPv6's localhost (::1). 
Memcached doesn't listen on it (since it doesn't support IPv6). 

I guess the reason is that you use 'localhost' in your scripts, 
which is by default mapped to both ip4 127.0.0.1 and ipv6 ::1.  

Changing 'localhost' in you scripts to '127.0.0.1' or removing 
IPv6 mapping should resolve the issue.

Maxim Dounin