Connecting to the HTTP interface fails

[Roy Graeme Harrison]

Connecting to the HTTP interface fails. The HTTP settings are the default 127.0.0.1:6789. I have seen this on 1.73 on Windows 10 and 1.75 on Windows 7. The console and log error is:

HTTP Client 127.0.0.1, Message Receive failed, WSAError 0

However looking at the source code, the code to get the error is commented out, so the real cause is a lack of received bytes. I have played with firewalls and failed to change this result.

Can anyone help please?

Thanks,

Roy Harrison

[smegnl]

I am having the exact same problem. no https with the DualDhcp product, which is the same as opendhcp with DNS added in.

[Andrew McMahon]

I was having this issue on Windows 10. I'm not sure if this was the actual fix or coincidental, but after clearing the DNS cache (from admin command prompt, "ipconfig /flushdns") and restarting OpenDHCPServer I'm no longer getting the error.

Edit: I spoke too soon, the server is running now and assigning IPs but the HTTP interface still doesn't work.

2nd Edit: Eventually got it working. I think the issue is with metrics in the routing table but I could be wrong. I changed HTTPServer to 127.0.0.1 rather than my adapter address (192.168.1.1) and now it will load.

[Roy Graeme Harrison]

Thanks, Andrew. I have worked around my problem by the fortunate situation of only having to provide a single fixed IP address. My code no longer needs to use the web page to discover the ragne of IP addresses that have been provided. That is no solution for most applications of course.

[dirk jaeckel]

I found a solution here: http://www.cosonok.com/2020/01/how-to-dhcp-with-open-dhcp-server-quick.html?showComment=1579955725154#c3449265255144615228
its NOT working when you not use the windows service but the RunStandAlone.bat
Log states for me: “HTTP Client 127.0.0.1, Message Receive failed, WSAError 0”.
after quiting the running opendchp.exe and starting the service it works

[Max Senft]

Hi.

Problem is a bug in OpenDHCPServer.cpp. It exists when OpenDHCPServer is run in the console using the "-v" argument.

I guess

void procHTTP(data19 *req)
{
...
    if (verbatim || cfig.dhcpLogLevel >= 1 && (errno || req->bytes <= 0))
    {
        sprintf(logBuff, "HTTP Client %s, Message Receive failed, WSAError %d", IP2String(tempbuff, req->remote.sin_addr.s_addr), errno);
...
}

should be

void procHTTP(data19 *req)
{
...
    if ((verbatim || cfig.dhcpLogLevel >= 1) && (errno || req->bytes <= 0))
    {
        sprintf(logBuff, "HTTP Client %s, Message Receive failed, WSAError %d", IP2String(tempbuff, req->remote.sin_addr.s_addr), errno);
...
}

--> There are round brackets missing to group the "verbatim || cfig.dhcpLogLevel >= 1" condition section.

Regards
Max
PS: It's sad that it's not possible to create fixes (i.e pull requests as over at GitHub).

[Taras]

I made changes to version 1.80 and compiled it