Well-known · Linux/Unix

873 rsync

TCP Yes
UDP
SCTP
DCCP

What it is

rsync daemon for file synchronization.

When / why

Backups and mirrors. Tunnel over SSH or restrict source IPs.

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.

Port range

Well-known (0–1023). System port for a core service. On Unix-like systems, binding it requires superuser privileges.

Browse all ports →

Firewall rules for port 873

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

ufw

sudo ufw allow proto tcp from <source> to any port 873

Allow TCP 873 (rsync). 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="873" protocol="tcp" accept'

Allow TCP 873 (rsync) from <source>. Run 'firewall-cmd --reload' afterwards.

nftables

nft add rule inet filter input ip saddr <source> tcp dport 873 accept

Allow TCP 873 (rsync). Assumes table 'inet filter' with an 'input' chain.

iptables

sudo iptables -A INPUT -p tcp -s <source> --dport 873 -j ACCEPT

Allow TCP 873 (rsync). Persist with iptables-save/netfilter-persistent.

Azure NSG

az network nsg rule create -g <resource-group> --nsg-name <nsg> -n Allow-rsync-873 --priority 1000 --access Allow --direction Inbound --protocol TCP --source-address-prefixes <source> --destination-port-ranges 873

Inbound rule for 873 (rsync). 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=873,ToPort=873,IpRanges="[{CidrIp=<source-cidr>}]"

Inbound TCP 873 (rsync). Replace <source-cidr> (e.g. 10.0.0.0/16).

GCP firewall

gcloud compute firewall-rules create allow-rsync-873 --direction=INGRESS --action=ALLOW --rules=tcp:873 --source-ranges=<source-cidr> --network=<network>

Ingress rule for 873 (rsync). Scope with --source-ranges and optionally --target-tags.

Windows netsh

netsh advfirewall firewall add rule name="Allow rsync 873/TCP" dir=in action=allow protocol=TCP localport=873 remoteip=<source>

Inbound TCP 873 (rsync). Set remoteip to a host/subnet; 'any' is discouraged.

Windows PowerShell

New-NetFirewallRule -DisplayName "Allow rsync 873/TCP" -Direction Inbound -Action Allow -Protocol TCP -LocalPort 873 -RemoteAddress <source>

Inbound TCP 873 (rsync). 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.