# Network Security and Default Port Restrictions

Network security is the set of technologies, policies, and processes designed to protect computer networks and their data from unauthorized access, cyber threats, and breaches.

We block several outbound ports for network security.

### **Blocked by Default**

* TCP [Port 25 (SMTP)](/neevcloud-guide/faq/how-to-request-unblocking-of-port-25-smtp.md)
* TCP & UDP Port 137 (NetBIOS Name Service)
* TCP & UDP Port 138 (NetBIOS Name Datagram)
* TCP & UDP Port 139 (NetBIOS Session)
* TCP & UDP Port 445 (SMB over TCP)
* TCP & UDP Port 5060 (VOIP/SIP)

You can request the removal of these blocks by submitting a [support ticket](https://docs.neevcloud.com/neevcloud-products/support).

### **Permanently Blocked**

These ports are commonly abused for DDOS attacks. These blocks are permanent and cannot be removed

* TCP & UDP Port 17
* TCP & UDP Port 19
* TCP & UDP Port 1900
* UDP Port 53413
* UDP Port 11211


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