ESP8266 Community Forum

I have been trying to do a TCP client connection to an IP address that is local to my router (it has no Internet visibility).

I can connect to a webserver using AT+CIPSTART=0,"TCP","www.google.com",80 . What I want to do is connect to a local webserver at 192.168.0.xxx:8000 . My browser connects to this ok.

I am trying the following: AT+CIPSTART=0,"TCP","192.168.0.xxx",8000 . I get either a response of "ERROR Unlink" or sometimes "DNS error" (or something like that). I have tried using an "http://" prefix and appending a ":" after the IP address (and all permutations of the same).

My best guess is that the chip is using some DNS that can't resolve the IP address because it is local.

My version is 0.9.2.4 . Any ideas would be much appreciated.

It was a pilot error on my part. The esp did evidently use a DNS server to search for the IP address and port number that I specified. I assumed that the IP address (i.e., 192.168.x.x and port was guaranteed to be local to my internal network. Evidently, there is an internet site with the same IP address and port number that is down. Thus, the esp couldn't connect. I changed the port number for my HTTP server at the local IP address and everything connected just fine.