Usama on Security

It is so sad that humans are not as dynamic and vibrant as the rhythms and energy around them           Islamabad- 13-12-2016 Commit an extreme act and you will divide people in two groups. One cheering in favor and one condemning the act strongly. Now support the narrative you want to be popular.           Islamabad- 21-3-2018

Recently I had to work with openvswitch to apply drop some VIP traffic on some particular IPs. The problem was that those particular IPs had port ranges and the job was to only block those particular IP addresses with a specific port range. Openvswitch does not allows to specify port ranges like numbers, so if i were to add a rule for port range e.g 7 to 14 I cannot specify it like 7 - 14. Instead, I must specify the first number and wildcard the port numbers until the least significant 1 of the number changes to 0. For example: Number            Binary           Number of trailing 0s            Covered Range               Port Mask      7                    0111                              0    ...