Monday, January 26, 2015

Router blocking HTTPS traffic?

Recently I had got a new cloud router for my broadband connection. Though the speed was very good, I was facing intermittent problems in accessing HTTPS sites. For e.g. webmail would hang sometimes, payment gateway pages would not load, Amazon app would not load screens, etc.

At first, I was not sure if the router was to blame, or was it the internet connection itself. A quick google search revealed that this is a common problem faced by many routers and had to do with the MTU (Maximum Transmission Unit) size limit. I was surprised that the MTU size would affect HTTPS which is a application level protocol.

The following links show an easy method to find out the correct MTU size for your network using the ping command. For e.g. ping -f -l 1472