I had this issue where I was only able to connect to websites like google.com and ibm.com when the mtu was set at 1500, but if I tried to connect to anything else, it would just show a blank page. When the mtu was lowered to 1499, it started working. I am curious as to why this works and if having the mtu set at 1499 could cause problems in the future? I actually don't know much about this, I just heard about it and am looking for a good explanation.
When I get an explanation of why the MTU was dropped by only 1 byte, I will update my question with the explanation.
Best Answer
That may mean some other device upstream from you has a smaller mtu and someone has mis-configured a firewall to block all ICMP preventing MTU discovery for the path.
Many naive network administrators seem to believe that ICMP has no purpose and you can completely block it without any repercussions.