[lwip-users] lwip minimal example, echo server

[Matthias Dübon]

Hello everyone,

I am quite new to lwip and I tested the lwip minimal example in the
lwip-contrib folder under a linux (Ubuntu) system. The example is
running, I see SNMP output messages but I am not able resp. I don't
understand how to use the echo server.
I turned on all debug messages and used a simple echo client program.
When sending some data to the echo server I got the following error
message:

./SimpleEchoClient -a 192.168.0.111 -p 7
ECHOCLNT: Error calling connect()

The output of the echo server is:
...
tcp_slowtmr: no active pcbs
tcp_slowtmr: no active pcbs
tcp_slowtmr: no active pcbs
tcp_slowtmr: no active pcbs
tcp_slowtmr: no active pcbs
tcp_slowtmr: no active pcbs
pbuf_alloc(length=42)
pbuf_alloc: allocated pbuf 0x637538
pbuf_alloc(length=42) == 0x637538
ethernet_input: dest:ff:ff:ff:ff:ff:ff, src:7a:13:c2:69:33:0e, type:806
pbuf_free(0x637538)
pbuf_free: deallocating 0x637538
tcp_slowtmr: no active pcbs
tcp_slowtmr: no active pcbs
pbuf_alloc(length=42)
pbuf_alloc: allocated pbuf 0x637538
pbuf_alloc(length=42) == 0x637538
ethernet_input: dest:ff:ff:ff:ff:ff:ff, src:7a:13:c2:69:33:0e, type:806
pbuf_free(0x637538)
pbuf_free: deallocating 0x637538
tcp_slowtmr: no active pcbs
pbuf_alloc(length=42)
pbuf_alloc: allocated pbuf 0x637538
pbuf_alloc(length=42) == 0x637538
ethernet_input: dest:ff:ff:ff:ff:ff:ff, src:7a:13:c2:69:33:0e, type:806
pbuf_free(0x637538)
pbuf_free: deallocating 0x637538
tcp_slowtmr: no active pcbs
etharp_timer

could that be a problem with the tap0 device? Any hints how can I debug this?

best
Matthias
ᐧ