Registered · Linux/Unix

3128 Squid proxy

TCP Unofficial
UDP No
SCTP
DCCP

What it is

Squid caching/forward web proxy default port.

When / why

Outbound web proxying and content filtering.

Protocol status detail

TransportStatusMeaning
TCP Unofficial Not assigned by IANA, but 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

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

Browse all ports →

Firewall rules for port 3128

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 3128

Allow TCP 3128 (Squid proxy). 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="3128" protocol="tcp" accept'

Allow TCP 3128 (Squid proxy) from <source>. Run 'firewall-cmd --reload' afterwards.

nftables

nft add rule inet filter input ip saddr <source> tcp dport 3128 accept

Allow TCP 3128 (Squid proxy). Assumes table 'inet filter' with an 'input' chain.

iptables

sudo iptables -A INPUT -p tcp -s <source> --dport 3128 -j ACCEPT

Allow TCP 3128 (Squid proxy). Persist with iptables-save/netfilter-persistent.

Azure NSG

az network nsg rule create -g <resource-group> --nsg-name <nsg> -n Allow-squidproxy-3128 --priority 1000 --access Allow --direction Inbound --protocol TCP --source-address-prefixes <source> --destination-port-ranges 3128

Inbound rule for 3128 (Squid proxy). 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=3128,ToPort=3128,IpRanges="[{CidrIp=<source-cidr>}]"

Inbound TCP 3128 (Squid proxy). Replace <source-cidr> (e.g. 10.0.0.0/16).

GCP firewall

gcloud compute firewall-rules create allow-squidproxy-3128 --direction=INGRESS --action=ALLOW --rules=tcp:3128 --source-ranges=<source-cidr> --network=<network>

Ingress rule for 3128 (Squid proxy). Scope with --source-ranges and optionally --target-tags.

Windows netsh

netsh advfirewall firewall add rule name="Allow Squid proxy 3128/TCP" dir=in action=allow protocol=TCP localport=3128 remoteip=<source>

Inbound TCP 3128 (Squid proxy). Set remoteip to a host/subnet; 'any' is discouraged.

Windows PowerShell

New-NetFirewallRule -DisplayName "Allow Squid proxy 3128/TCP" -Direction Inbound -Action Allow -Protocol TCP -LocalPort 3128 -RemoteAddress <source>

Inbound TCP 3128 (Squid proxy). 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.