The previous answer address why the
ufw command didn't have an effect. However it does not explain why the
ip route command had no effect.
The reason it had no effect for you is that
78.128.113 is being interpreted as
22.214.171.124/32. Thus you are blocking only a single IP address which is not the one you are receiving traffic from. If you wanted to block the entire /24 IP range, you could use:
ip route add unreachable 126.96.36.199/24
It's important to notice that the
ip command will only block the return traffic not the incoming traffic. That means incoming traffic from that IP range may still consume some resources on your host by creating half-open TCP connections or sending packets to stateless services (usually UDP based).
For those reasons a firewall rule such as those created with
ufw will likely work better for your particular use case than an
ip route command.