Well-known · Network

639 MSDP

TCP Yes
UDP
SCTP
DCCP

What it is

Multicast Source Discovery Protocol.

When / why

Inter-domain multicast.

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 639

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 639

Allow TCP 639 (MSDP). 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="639" protocol="tcp" accept'

Allow TCP 639 (MSDP) from <source>. Run 'firewall-cmd --reload' afterwards.

nftables

nft add rule inet filter input ip saddr <source> tcp dport 639 accept

Allow TCP 639 (MSDP). Assumes table 'inet filter' with an 'input' chain.

iptables

sudo iptables -A INPUT -p tcp -s <source> --dport 639 -j ACCEPT

Allow TCP 639 (MSDP). Persist with iptables-save/netfilter-persistent.

Azure NSG

az network nsg rule create -g <resource-group> --nsg-name <nsg> -n Allow-msdp-639 --priority 1000 --access Allow --direction Inbound --protocol TCP --source-address-prefixes <source> --destination-port-ranges 639

Inbound rule for 639 (MSDP). 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=639,ToPort=639,IpRanges="[{CidrIp=<source-cidr>}]"

Inbound TCP 639 (MSDP). Replace <source-cidr> (e.g. 10.0.0.0/16).

GCP firewall

gcloud compute firewall-rules create allow-msdp-639 --direction=INGRESS --action=ALLOW --rules=tcp:639 --source-ranges=<source-cidr> --network=<network>

Ingress rule for 639 (MSDP). Scope with --source-ranges and optionally --target-tags.

Windows netsh

netsh advfirewall firewall add rule name="Allow MSDP 639/TCP" dir=in action=allow protocol=TCP localport=639 remoteip=<source>

Inbound TCP 639 (MSDP). Set remoteip to a host/subnet; 'any' is discouraged.

Windows PowerShell

New-NetFirewallRule -DisplayName "Allow MSDP 639/TCP" -Direction Inbound -Action Allow -Protocol TCP -LocalPort 639 -RemoteAddress <source>

Inbound TCP 639 (MSDP). 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.