Well-known · Cross-platform

113 Ident

TCP Yes
UDP No
SCTP
DCCP

What it is

Identification protocol historically used by IRC and mail servers.

When / why

Mostly legacy; some daemons still query it during connection setup.

Protocol status detail

TransportStatusMeaning
TCP Yes Assigned by IANA and standardized, specified, or widely used on this port.
UDP No Not assigned, standardized, or widely used on this port.
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 113

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 113

Allow TCP 113 (Ident). 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="113" protocol="tcp" accept'

Allow TCP 113 (Ident) from <source>. Run 'firewall-cmd --reload' afterwards.

nftables

nft add rule inet filter input ip saddr <source> tcp dport 113 accept

Allow TCP 113 (Ident). Assumes table 'inet filter' with an 'input' chain.

iptables

sudo iptables -A INPUT -p tcp -s <source> --dport 113 -j ACCEPT

Allow TCP 113 (Ident). Persist with iptables-save/netfilter-persistent.

Azure NSG

az network nsg rule create -g <resource-group> --nsg-name <nsg> -n Allow-ident-113 --priority 1000 --access Allow --direction Inbound --protocol TCP --source-address-prefixes <source> --destination-port-ranges 113

Inbound rule for 113 (Ident). 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=113,ToPort=113,IpRanges="[{CidrIp=<source-cidr>}]"

Inbound TCP 113 (Ident). Replace <source-cidr> (e.g. 10.0.0.0/16).

GCP firewall

gcloud compute firewall-rules create allow-ident-113 --direction=INGRESS --action=ALLOW --rules=tcp:113 --source-ranges=<source-cidr> --network=<network>

Ingress rule for 113 (Ident). Scope with --source-ranges and optionally --target-tags.

Windows netsh

netsh advfirewall firewall add rule name="Allow Ident 113/TCP" dir=in action=allow protocol=TCP localport=113 remoteip=<source>

Inbound TCP 113 (Ident). Set remoteip to a host/subnet; 'any' is discouraged.

Windows PowerShell

New-NetFirewallRule -DisplayName "Allow Ident 113/TCP" -Direction Inbound -Action Allow -Protocol TCP -LocalPort 113 -RemoteAddress <source>

Inbound TCP 113 (Ident). 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.