Port 5445SMB Direct (SMB over RDMA)

SMB Direct carries SMB traffic over RDMA-capable network adapters for high-performance file sharing.

transport: tcp · sctp
in transit: cleartext
assignment: official
risk: 6/10
lookups: 0

1 other service is registered on port 5445. compare all 2 →

Technical Details

what runs on :5445

SMB Direct carries SMB protocol traffic over Remote Direct Memory Access (RDMA), using adapters and fabrics such as iWARP, RoCE, or InfiniBand to reduce CPU use and latency. Microsoft implementations use port 5445 for SMB Direct connection setup and transport; SMB negotiation and session setup commonly begin on port 445, with SMB Multichannel able to establish RDMA channels for the session. The protocol negotiates connection parameters and uses credit-based flow control to move SMB messages, including data transferred directly through RDMA operations. IANA lists the assignment for TCP and SCTP; actual deployments require compatible SMB software and RDMA networking.

Security Information

exposure of :5445

risk score

6/ 10risk

treat as sensitive. widely scanned and regularly exploited when reachable — restrict it to known sources.

file transfer averages 3.4 across 186 ports — this one sits 2.6 above.

in transit

cleartext

credentials and payloads are readable by anyone on path

assignment

official

registered with iana for this service — scanners fingerprint it by number

reachable over

tcp · sctp

every listening transport is another surface to filter at the edge

security overview

Treat this as an SMB service endpoint: restrict it to trusted storage or server networks and do not expose it to the public internet. An attacker who can reach it may probe the SMB implementation and attempt authentication or exploit a protocol or implementation vulnerability; SMB encryption is supported in SMB 3 but is not enabled by default in every deployment. RDMA requirements reduce the chance of encountering it on ordinary internet hosts, but are not a security boundary.

Record

iana registry entry

port: :5445
service: SMB Direct (SMB over RDMA)
transport: TCPSCTP
encryption: cleartext
assignment: iana registered
risk: 6/10risk
category: File Transfer Network Services
usage: This is the Microsoft SMB Direct transport used by SMB 3.x systems with RDMA-capable network adapters, typically in data centers and storage networks. It usually supplements ordinary SMB connections on port 445 rather than serving as a general-purpose internet file-sharing endpoint.
lookups: 0rank 993
added: 2026-10-08
updated: 2026-10-08
references: IANA service name registry — port 5445

Something wrong?

This record is maintained by the engineers who use port 5445. Every field on it is editable — change what's wrong, say how you know, and a reviewer publishes it, usually within a minute. Last touched 2026-10-08.

01edit any field on a page of its own
02a model checks it for accuracy and spam
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edit this record →back to the registry

Related Ports

all 186 in file transfer →

the 8 most looked-up other ports in file transfer — 186 ports carry that label.

port	service	proto	category	risk	views
:9080	Groove RPC	TCPUDP	Web Services	caution	70.8k
:17500	Dropbox LAN Sync	TCPUDP	File Transfer	caution	43.7k
:548	Apple Filing Protocol	TCP	File Transfer	caution	36.8k
:7000	Vuze HTTPS Tracker	TCPtls	Security	caution	28.9k
:1337	PowerFolder P2P	TCP	Security	caution	27.1k
:9001	SharePoint Authoring		Web Services	caution	26.3k
:8080	FilePhile Relay	UDP	File Transfer	caution	25.6k
:1337	WASTE Encrypted Sharing	TCP	Security	caution	22.9k

risk mix of the 8 listed

caution100%

1 of 8 encrypted

Port :5445SMB Direct (SMB over RDMA)

Technical Details

Security Information

Related Ports

Port 5445SMB Direct (SMB over RDMA)