Registered · Windows

1433 Microsoft SQL Server

TCP Yes
UDP —
SCTP —
DCCP —

What it is

Default MSSQL database engine TCP listener.

When / why

App-to-database traffic. Never internet-exposed; restrict to app tiers.

Protocol status detail

TransportStatusMeaning
TCP Yes Assigned by IANA and standardized, specified, or widely used on this port.
UDP — Not applicable for this transport.
SCTP — Not applicable for this transport.
DCCP — Not applicable for this transport.
« 1414 IBM MQ 1434 MSSQL Monitor (SQL Browser) »

Port range

Registered (1024–49151). Assigned by IANA on request; usable without elevated privileges on most systems.

Browse all ports →

Firewall rules for port 1433

Copy-ready inbound rules for the active transports. Replace every <source> placeholder with the specific host, subnet, or CIDR that should reach this port.

⚠ High exposure risk — this service should never be reachable from untrusted networks. Scope the rule to a management subnet or VPN.

ufw

sudo ufw allow proto tcp from <source> to any port 1433

Allow TCP 1433 (Microsoft SQL Server). Replace <source> with the network/host that should reach it.

firewalld

sudo firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<source>" port port="1433" protocol="tcp" accept'

Allow TCP 1433 (Microsoft SQL Server) from <source>. Run 'firewall-cmd --reload' afterwards.

nftables

nft add rule inet filter input ip saddr <source> tcp dport 1433 accept

Allow TCP 1433 (Microsoft SQL Server). Assumes table 'inet filter' with an 'input' chain.

iptables

sudo iptables -A INPUT -p tcp -s <source> --dport 1433 -j ACCEPT

Allow TCP 1433 (Microsoft SQL Server). Persist with iptables-save/netfilter-persistent.

Azure NSG

az network nsg rule create -g <resource-group> --nsg-name <nsg> -n Allow-microsoftsqlserver-1433 --priority 1000 --access Allow --direction Inbound --protocol TCP --source-address-prefixes <source> --destination-port-ranges 1433

Inbound rule for 1433 (Microsoft SQL Server). Set <source> to a CIDR; lower priority number = higher precedence.

AWS Security Group

aws ec2 authorize-security-group-ingress --group-id <sg-id> --ip-permissions IpProtocol=tcp,FromPort=1433,ToPort=1433,IpRanges="[{CidrIp=<source-cidr>}]"

Inbound TCP 1433 (Microsoft SQL Server). Replace <source-cidr> (e.g. 10.0.0.0/16).

GCP firewall

gcloud compute firewall-rules create allow-microsoftsqlserver-1433 --direction=INGRESS --action=ALLOW --rules=tcp:1433 --source-ranges=<source-cidr> --network=<network>

Ingress rule for 1433 (Microsoft SQL Server). Scope with --source-ranges and optionally --target-tags.

Windows netsh

netsh advfirewall firewall add rule name="Allow Microsoft SQL Server 1433/TCP" dir=in action=allow protocol=TCP localport=1433 remoteip=<source>

Inbound TCP 1433 (Microsoft SQL Server). Set remoteip to a host/subnet; 'any' is discouraged.

Windows PowerShell

New-NetFirewallRule -DisplayName "Allow Microsoft SQL Server 1433/TCP" -Direction Inbound -Action Allow -Protocol TCP -LocalPort 1433 -RemoteAddress <source>

Inbound TCP 1433 (Microsoft SQL Server). Replace <source> with a host or subnet.

Rules are generated only for transports marked active for this port. They default to an inbound allow with an explicit source placeholder — never any. Review direction, scope, and rule precedence before applying in production.