This list is about essential TCP/UDP port numbers that an administrator running SQL Server / Cluster requires to know when configuring the firewall or otherwise.
It includes those used under OS, server-based programs & their subcomponents. Certainly do let me know for any corrections that I may have missed out.

Frequently Used Ports

Service Type Port# Comments
Default Instance TCP 1433 Official socket allocated by IANA to Ms for SQL Server, this can be changed to anything above 1024.
Named Instance TCP xxxxx As & what you assign in the dynamic port range. There have been changes since Win 6, see below for the available range.
DAC Default Instance TCP 1434 Remote connections through DAC are disabled unless turned on manually. For named instance ports other than 1434 are used.
SQL Browser / SQL Server Resolution Protocol UDP 1434 Used by an application level protocol SSRP on top of which the browser service runs.It helps when connecting to non-hidden instances named instances. In such cases TCP port is dynamic (unless specified) & determined when the Database Engine starts. It’s not needed if all connections contain the port#. When uninstalling SQL 9.0 from a machine running SQL 8.0 check the existence of registry key IsListenerActive, because if it exists SSRP will fail to listen.Denali Browser does not support sending information about SQL 8.0 instances.Refer à
MULTICAST UDP   Allows multicast response on UDP (Browser Service Enumerations)
3882 Be cautious a malformed request to port 3882/tcp can cause DOS. When communicating with remote SSIS port 135 is used & if it’s a SSIS package is running against a database server you need 1433 or as specified. Uses msdts1 protocol for service type msdts1.
SSAS TCP 2393, 2394, 2725 OLAP Services 7.0 used TCP ports 2393 & 2394. Though Ms has reserved UDP ports 2393 & 2394 those are not used by OLAP Services. Analysis Services uses TCP port 2725. For backward compatibility, Analysis Services uses TCP ports 2393 & 2394 when connected with an OLAP Services 7.0 client.
SSAS TCP 2383 Standard port for the default instance of Analysis Services. User configurable;
Browser SSAS TCP 2382 Client connection requests for a named instance of Analysis Services that do not specify a port number are directed to SQL Server Browser.
RDP TCP 3389 Providing the remote desktop to a client or VDI keep your eyes open because the default encryption certificate (RSA pk stored in mstlsapi.dll), is there with widows base install. A Man-in-the-Middle (MITM) attack can intercept the exchange of RDP encryption information. Check here for safety ribbons secure RDP using Transport Layer Security 6.0 Network Level Authentication offers much stronger protection
Dynamic Port Range To comply with Internet Assigned Numbers Authority recommendations, Ms has increased the dynamic client port range for outgoing connections. Since the release of Win 6.0 new default port range is 49152 – 65535 which was earlier 1025 through 5000.
Service Broker TCP   User configurable; there is no default port. BOL conventional configuration uses TCP 4022.
SSL TCP 443 When used with HTTP forming HTTPS, it provides an encrypted communication channel.
HTTP endpoint     Used when connecting through a url, this is user configurable; this can be customized while creating an endpoint. Port 80 for CLEAR_PORT traffic & 443 for SSL_PORT traffic.
HTTPS endpoint TCP 443 Default instance running over an HTTPS endpoint, used for a connection through url which used SSL.
3260, 860  
SQL Agent File Copy 135 Agent to copy backup files to the shared folder on the standby server.  
137, 138, 139, 445 File copy on UNC shares.
SQL Debugger TCP 135 Exception for IPsec traffic might also require you to set an inbound rule for 500 & 4500 if IPsec is used for network communication.After opening port 135 include the applications Visual Studio à Devenv.exe / Management Studio à ssms.exe.
Database Mirroring     User configurable; there is no default port. While setting multiple instances be cautious to not to break the quorum. BOL conventional configuration uses TCP 7022.
Replication TCP 1433 For push transactional replication a working 1433 between distributor & subscriber is all you need, however in pull subscriptions few other ports are needed; when you launch an initialization of a subscriber SQL uses the windows default port 445 for mapped drives to copy down scripts.FTP (21) can be used initially to transfer schema & data over the internet; it can also use HTTP (80) or File & Print Sharing (ports 137,138, 139).You can put merge replication to use WEB synchronization using port 80 or encrypted 443. Replication uses the IIS endpoint, when syncing over HTTP (80 by default but configurable), however IIS process connects to SQL Server through standard ports. Keep in mind when synchronizing over the Web using FTP, there is no transfer between subscriber & IIS, it’s all amid IIS & the publisher.
Cluster Service UDP 3343 Cluster services control & manage the cluster database. Like the Heartbeat process - Cluster network driver (Clusnet.sys) performs intra-node communication between each node of the cluster by periodically exchanging sequenced, unicast/multicast UDP datagrams in the cluster. This determines whether all nodes are running correctly & network links are healthy. Generally this does not happens over the public network.There are cases when the range of random available IP ports that the cluster service uses to initiate communication through RPCs is less than 100 ports & connection to the Cluster Admin fails (refer to 154596( ) ).RPC – 135 / Cluster Network Drv – 3343 / SMB – 445 / NetBIOS – 139 / RPC 5000-5099 / 8011-8031·  135 (RPC endpoint mapper/DCOM), (RPC endpoint mapper over UDP).·  For nodes running multiple services, ports 5000-5099 (or more) may be needed for remote RPC connectivity. If closed, error 1721 might occur when you connect to a remote cluster.
             Cluster service requires at least 100 ports for communication through RPC. Count of ports available may get too low when other services like DNS, WINS, Ms SQL Server service & others are using some of the necessary ports.·  Ports 8011-8031 must be open for internode RPC connectivity or the cluster log will indicate that a SPONSOR is not available. Again these errors occur because there are not enough ports available for RPC communication between a node trying to join the cluster & a node that can sponsor the new node.
Cluster Admin UDP 137
Random Ports UDP Check dynamic port range
Filestream     139 & 445.
WMI TCP 135 Used by SSCM, it runs over DCOM (aka Network OLE) when accessing remote data. After initial connection DCOM randomly assigns a port for further communication where some tools may require a TCP port > 1024 (aka TCP high port) opened on the remote host.
IPsec traffic UDP 500 & 4500 Should be set to allow ISAKMP traffic to be forwarded for both inbound & outbound filters.
MsDTC   RPC Since NT 4, MSDTC has been performing as the transaction coordinator for components with COM & .NET architectures. Connected resources can be databases, message queues or file systems which may be distributed. Messages are sent on TCP 135 while the responses are on a dynamically assigned port.

Additionally check this for the loose vines you might don’t know you have.

SELECT name, protocol_desc, port, state_desc, type_desc FROM sys.tcp_endpoints WHERE type_desc in ('DATABASE_MIRRORING','SERVICE_BROKER')


  • How to capture network traffic with Network Monitor KB 148942
  • Basics of Reading TCP/IP Traces KB 169292
  • Service overview & network port requirements for Windows Server system KB 832017
  • How to configure RPC dynamic port allocation to work with firewalls KB 154596
  • TCP Ports Needed for Communication to SQL Server through a Firewall KB 287932