Bitcoin clients connect to other bitcoin nodes on TCP port 8333 by default. Some Bitcoin users have reported issues attempting to connect or receive connections to their bitcoin clients across port 8333, according to a latest report by CCN.
After spending an entire day in vain trying to open 8333, one ATT U-verse (a bundled package similar to others offered by well-known Cable Companies/ISPs) customer approached customer support.
“After hours of phone calls and messaging ATT finally told me the truth of what was going on, and only because I noticed it myself and demanded an answer. The internet is being routed through a DVR/cable box, and they confirmed the DVR also has a firewall.”
The problem arises when the ISP has complete control over the hardware from the user’s house to their router to the Internet. Many well-known providers will deliberately close a number of connection ports to facilitate what they believe to be the optimum level of service.
“Perhaps this is the driving force behind the inexplicable and massive decline in Bitcoin nodes. Bitcoin is being censored by the ISPs themselves, and they won’t even tell you that. I had to get in touch with headquarters and threaten to rip it out of the wall to get a proper answer”, the ATT U-verse customer concluded.
However, the report points out that while some ISP may indeed be blocking port 8333, they are not singling that particular port out, and instead they are blocking ports en masse.
If users are uncertain whether their ISPs are blocking Bitcoin, they may choose to conduct an inbound port test. A web search of “port testing” will give users some free services to pick from. Performing a port scan on port 8333 on their own connection will let the users know if ISP is blocking it or not.
If the user’s ISP does happen
Originally appeared at: http://www.econotimes.com/Is-bitcoin-being-deliberately-blocked-by-ISPs-83816