Port 3723Battle.net Gaming
Port 3723 is widely used by many Blizzard Entertainment games through their Battle.net service, including iconic titles such as Diablo II, Warcraft II, Warcraft III, and StarCraft. The port facilitates game server communication, matchmaking, lobby coordination, and real-time multiplayer data exchange, supporting both TCP and UDP traffic to ensure smooth gameplay across different network conditions..
- transport
- tcp · udp
- in transit
- cleartext
- assignment
- unofficial
- risk
- 4/10
- lookups
- 9,247
2 transports registered
payload readable on path
used by convention
caution
rank 520 of 993 · top 52%
Technical Details
what runs on :3723Port 3723 serves as a key communication channel for Blizzard’s legacy Battle.net gaming platform. It enables various gameplay elements, including matchmaking, player authentication, chat functionalities, and in-game event synchronization. The port can handle both TCP and UDP protocols, which allows for flexible, reliable communication as well as fast transmission suited for real-time multiplayer gaming.
Typically, TCP is leveraged for reliable delivery of critical data such as login procedures, session management, and messaging, while UDP assists in low latency communication for gameplay data that requires speed over guaranteed arrival. This blend supports responsive game experiences without sacrificing essential connection stability. Because multiple classic Blizzard titles share this port, network administrators may observe concurrent or overlapping traffic types during active gameplay sessions.
Although port 3723 is considered an ‘unofficial’ port by IANA standards, it has become a standardized de facto listening port for Blizzard’s legacy games. Awareness of this can facilitate correct firewall rules and NAT configurations when supporting players or hosting custom servers reliant on older Blizzard software.
Security Information
exposure of :3723risk score
4/ 10caution
worth attention. how exposed you are depends on configuration — don't leave it reachable from the internet without a reason.
network services averages 3.9 across 604 ports — this one sits 0.1 above.
in transit
cleartext
credentials and payloads are readable by anyone on path
assignment
unofficial
used by convention, not registered — what answers here varies by deployment
reachable over
tcp · udp
udp is connectionless — source addresses are trivially spoofed and it is a reflection favourite
security overview
Common Vulnerabilities:
- Man-in-the-middle attacks: Since encryption is typically not enforced on this port, attackers may intercept or manipulate game traffic.
- Unauthorized access: An open port 3723 might be probed or exploited by attackers attempting to impersonate game clients or servers.
- DDoS amplification: Combined UDP/TCP nature can expose attack vectors for denial of service via traffic flooding, disrupting gameplay or game servers.
Mitigations:
- Restrict port exposure: Limit traffic on port 3723 to known and trusted IP ranges to minimize attack surface.
- Implement deep packet inspection: Utilize IDS/IPS solutions to detect anomalous or malicious traffic targeting or draining port 3723.
- Segmentation: Isolate game servers from sensitive network segments, creating boundaries that limit potential lateral movement.
- Apply rate limiting/connection throttling: Protect servers from brute-force attacks or DDoS by managing the volume of connections.
- Update game clients and servers: Ensure software is up to date with any vendor-provided security improvements.
Related Ports
the 8 most looked-up other ports in network services — 604 ports carry that label.
| port | service | risk | |||
|---|---|---|---|---|---|
| :9080 | Groove RPC | TCPUDP | Web Services | caution | 70.8k |
| :6543 | Jetnet | UDP | Network Services | caution | 65.3k |
| :5938 | TeamViewer | TCPUDP | Remote Access | caution | 65.0k |
| :8291 | Winbox MikroTik Admin | TCP | Security | caution | 62.9k |
| :3233 | WhiskerControl Protocol | TCPUDP | Network Services | caution | 61.9k |
| :3268 | Microsoft Global Catalog (GC) | TCPUDP | Security | caution | 54.6k |
| :135 | Microsoft EPMAP | TCPUDP | Security | caution | 51.9k |
| :3128 | Tatsoft Default HTTP Proxy | TCP | Web Services | caution | 46.8k |
risk mix of the 8 listed
- caution100%
0 of 8 encrypted