Thread: data storage - struct or hash table

I am writing a proxy server, an internal table will need to keep track of requests so incoming traffic can be dropped if it has not been requested and maintain connection state.

I will need to store

Originating Internal IP (unsigned long)
Destination IP (unsigned long)
Source port (uint)
Destination ports (uint)

I will need to store a lot of these in data records and will need to access them qucickly. Would it be more efficient to store them in a hash table or a struct?
Or is tere a more suitable data type?

thanks