Monitoring web servers don’t always follow RFCs

Posted on February 25th, 2011

Today a customer contacted me saying Overseer Network Monitoring Software gave this error when trying to monitor an RFID Reader device:

The server committed a protocol violation. Section=ResponseHeader Detail=CR must be followed by LF

As you can see, the error message is pretty clear that the server is violating RFC standards that state a carriage return(CR) must be followed by a line feed(LF). These RFCs have been around for a long time, but this is not the first time I’ve experienced firmware developers’ HTTP implementation falling short of RFC standards. I’m not a firmware developer, so there may be some good reasons for this– but at the same time, my customers need to be able to monitor any website, standards-compliant or not.

Therefore, I was able to find a work-around to let Overseer monitor a website when it experienced this sort of error. This is available in Overseer Network Monitor 4.1.24.