Well-known · Cross-platform

546 DHCPv6 client

TCP Yes
UDP Yes
SCTP —
DCCP —

What it is

DHCPv6 client port.

When / why

IPv6 address/prefix assignment, client side.

Protocol status detail

TransportStatusMeaning
TCP Yes Assigned by IANA and standardized, specified, or widely used on this port.
UDP Yes Assigned by IANA and standardized, specified, or widely used on this port.
SCTP — Not applicable for this transport.
DCCP — Not applicable for this transport.
« 544 kshell 547 DHCPv6 server »

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 546

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 546

Allow TCP 546 (DHCPv6 client). Replace <source> with the network/host that should reach it.

sudo ufw allow proto udp from <source> to any port 546

Allow UDP 546 (DHCPv6 client). 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="546" protocol="tcp" accept'

Allow TCP 546 (DHCPv6 client) from <source>. Run 'firewall-cmd --reload' afterwards.

sudo firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<source>" port port="546" protocol="udp" accept'

Allow UDP 546 (DHCPv6 client) from <source>. Run 'firewall-cmd --reload' afterwards.

nftables

nft add rule inet filter input ip saddr <source> tcp dport 546 accept

Allow TCP 546 (DHCPv6 client). Assumes table 'inet filter' with an 'input' chain.

nft add rule inet filter input ip saddr <source> udp dport 546 accept

Allow UDP 546 (DHCPv6 client). Assumes table 'inet filter' with an 'input' chain.

iptables

sudo iptables -A INPUT -p tcp -s <source> --dport 546 -j ACCEPT

Allow TCP 546 (DHCPv6 client). Persist with iptables-save/netfilter-persistent.

sudo iptables -A INPUT -p udp -s <source> --dport 546 -j ACCEPT

Allow UDP 546 (DHCPv6 client). Persist with iptables-save/netfilter-persistent.

Azure NSG

az network nsg rule create -g <resource-group> --nsg-name <nsg> -n Allow-dhcpv6client-546 --priority 1000 --access Allow --direction Inbound --protocol "*" --source-address-prefixes <source> --destination-port-ranges 546

Inbound rule for 546 (DHCPv6 client). 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=546,ToPort=546,IpRanges="[{CidrIp=<source-cidr>}]"

Inbound TCP 546 (DHCPv6 client). Replace <source-cidr> (e.g. 10.0.0.0/16).

aws ec2 authorize-security-group-ingress --group-id <sg-id> --ip-permissions IpProtocol=udp,FromPort=546,ToPort=546,IpRanges="[{CidrIp=<source-cidr>}]"

Inbound UDP 546 (DHCPv6 client). Replace <source-cidr> (e.g. 10.0.0.0/16).

GCP firewall

gcloud compute firewall-rules create allow-dhcpv6client-546 --direction=INGRESS --action=ALLOW --rules=tcp:546,udp:546 --source-ranges=<source-cidr> --network=<network>

Ingress rule for 546 (DHCPv6 client). Scope with --source-ranges and optionally --target-tags.

Windows netsh

netsh advfirewall firewall add rule name="Allow DHCPv6 client 546/TCP" dir=in action=allow protocol=TCP localport=546 remoteip=<source>

Inbound TCP 546 (DHCPv6 client). Set remoteip to a host/subnet; 'any' is discouraged.

netsh advfirewall firewall add rule name="Allow DHCPv6 client 546/UDP" dir=in action=allow protocol=UDP localport=546 remoteip=<source>

Inbound UDP 546 (DHCPv6 client). Set remoteip to a host/subnet; 'any' is discouraged.

Windows PowerShell

New-NetFirewallRule -DisplayName "Allow DHCPv6 client 546/TCP" -Direction Inbound -Action Allow -Protocol TCP -LocalPort 546 -RemoteAddress <source>

Inbound TCP 546 (DHCPv6 client). Replace <source> with a host or subnet.

New-NetFirewallRule -DisplayName "Allow DHCPv6 client 546/UDP" -Direction Inbound -Action Allow -Protocol UDP -LocalPort 546 -RemoteAddress <source>

Inbound UDP 546 (DHCPv6 client). 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.