Registered · Windows

6601 MS Forefront TMG

TCP Yes
UDP
SCTP
DCCP

What it is

Microsoft Forefront Threat Management Gateway.

When / why

Legacy Microsoft proxy/firewall.

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

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

Browse all ports →

Firewall rules for port 6601

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 6601

Allow TCP 6601 (MS Forefront TMG). 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="6601" protocol="tcp" accept'

Allow TCP 6601 (MS Forefront TMG) from <source>. Run 'firewall-cmd --reload' afterwards.

nftables

nft add rule inet filter input ip saddr <source> tcp dport 6601 accept

Allow TCP 6601 (MS Forefront TMG). Assumes table 'inet filter' with an 'input' chain.

iptables

sudo iptables -A INPUT -p tcp -s <source> --dport 6601 -j ACCEPT

Allow TCP 6601 (MS Forefront TMG). Persist with iptables-save/netfilter-persistent.

Azure NSG

az network nsg rule create -g <resource-group> --nsg-name <nsg> -n Allow-msforefronttmg-6601 --priority 1000 --access Allow --direction Inbound --protocol TCP --source-address-prefixes <source> --destination-port-ranges 6601

Inbound rule for 6601 (MS Forefront TMG). 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=6601,ToPort=6601,IpRanges="[{CidrIp=<source-cidr>}]"

Inbound TCP 6601 (MS Forefront TMG). Replace <source-cidr> (e.g. 10.0.0.0/16).

GCP firewall

gcloud compute firewall-rules create allow-msforefronttmg-6601 --direction=INGRESS --action=ALLOW --rules=tcp:6601 --source-ranges=<source-cidr> --network=<network>

Ingress rule for 6601 (MS Forefront TMG). Scope with --source-ranges and optionally --target-tags.

Windows netsh

netsh advfirewall firewall add rule name="Allow MS Forefront TMG 6601/TCP" dir=in action=allow protocol=TCP localport=6601 remoteip=<source>

Inbound TCP 6601 (MS Forefront TMG). Set remoteip to a host/subnet; 'any' is discouraged.

Windows PowerShell

New-NetFirewallRule -DisplayName "Allow MS Forefront TMG 6601/TCP" -Direction Inbound -Action Allow -Protocol TCP -LocalPort 6601 -RemoteAddress <source>

Inbound TCP 6601 (MS Forefront TMG). 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.