Re: [lwip-users] portscan

[Bernhard 'Gustl' Bauer]

Kieran Mansley schrieb:
> On Mon, 2009-06-29 at 07:42 +0200, Bernhard 'Gustl' Bauer wrote:
> > Unfortunately I have no 
> > access to the status output when this happens.
> >
> > Any idea what can be done about this.
>
> Without some more information about how and why it's crashing there's
> not a lot that we can do I'm afraid.

I just went through my defines. There are two I'm not sure about it:

Part of lwipopts.h:
------------
/**
 * MEMP_NUM_TCP_PCB: the number of simulatenously active TCP connections.
 * (requires the LWIP_TCP option)
 */
//#define MEMP_NUM_TCP_PCB                5
//#define MEMP_NUM_TCP_PCB                10
//#define MEMP_NUM_TCP_PCB                60
#define MEMP_NUM_TCP_PCB                100

/**
 * MEMP_NUM_TCP_PCB_LISTEN: the number of listening TCP connections.
 * (requires the LWIP_TCP option)
 */
//#define MEMP_NUM_TCP_PCB_LISTEN         8
#define MEMP_NUM_TCP_PCB_LISTEN         16
-----------

The default values are MEMP_NUM_TCP_PCB = 5 and MEMP_NUM_TCP_PCB_LISTEN 
        = 8. I wonder why there should be more listening connections 
than active connections. Shouldn't the numbers be equal?

I can remember having troubles with low MEMP_NUM_TCP_PCB numbers so I 
increased it to 100.

What happens if a TCP connection goes from listening to active? Is 
another listening created? When I set MEMP_NUM_TCP_PCB_LISTEN back to 8 
my situation seams to improve a bit.

TIA

Gustl