Why is my Ubuntu computer only connected at 100Mbps?

I was doing a local server-to-server file transfer and noticed the speed was capping at 11.90MB/s…which is about 100Mbps–small (b) represents a “bit”, capital (B) represents a Byte…There are 8 bits in a byte.

How strange I thought, considering I have a gigabit network router and both of my servers are gigabit capable…

In short, I stumbled across a little bit of code which allowed me to troubleshoot the problem.

First, lets examine the current speed the network card is connected at by using this little command line tool: 

cat /sys/class/net/enp1s0/speed

It will report either 10/100/1000 depending what your network connection speed is, in bits..Mine was set to 100..

Perplexed, I considered for a moment, maybe the network cable I used on this new server wasn’t up to speed..

Sure enough, it was a Cat 5 cable.. I dug through my box of spare cables (lots of Cat 5’s) and found an adequate Cat 5e cable and swapped it out.

Running the command once again confirmed 1000…Problem solved!

I hope this was helpful.