Technical Implementation Detailed Steps For Binding And Routing Taiwan's Native Static Residential IPs

1.

Preparation and information gathering

Please first confirm the static IP data provided by your ISP: public IP, subnet mask (or CIDR), default gateway, primary/secondary DNS, and whether interfaces need to be bound or specified by MAC.
Equipment: A home router or OpenWrt/RouterOS/pfSense that supports static WAN settings, with SSH or Web GUI login; The MAC and private IP address of the host to be bound internally.

2.

Confirm the ISP connection mode (PPPoE/DHCP/Static).

Log in to the router's web GUI or contact your ISP customer service to confirm the wiring mode.
If it's PPPoE but has a static IP, usually after PPPoE dial-up, you still need to enter the ISP's static address or enable the 'Bridge + Public IP to Internal Machine' mode on the router.
Note the interface name (e.g., eth0, eth1, or pppoe-wan).

3.

Set the WAN static IP on the router's web GUI (general steps

). Steps: 1) Log in to the router → Network/Internet → WAN. 2) Select either "Static IP" or "Manual." 3) Enter the IP, Netmask, Gateway, and DNS provided by your ISP. 4) Save and restart the WAN interface.
Verification: The WAN status page shows UP and the IP is the address; Perform external ping (such as 8.8.8.8) to test the connection.

4.

Configure static WAN (command example) on OpenWrt using the CLI

Steps: SSH logs in to OpenWrt and edits /etc/config/network. Example configuration snippet:
config interface 'wan'
option proto 'static'
option ipaddr 'A.B.C.D'
option netmask '255.255.255.0'
option gateway 'A.B.C.1'
option dns '1.1.1.1 8.8.8.8'
After saving, execute /etc/init.d/network restart.
Use IP addr show WAN, IP route, and ping 8.8.8.8 for authentication.

5.

Bind the public IP to the internal host (1:1 NAT or DMZ configuration).

If the ISP provides multiple public IPs and wants to map one directly to the internal host, it is recommended to use "1:1 NAT (static mapping)":
the router GUI → NAT / One-to-One NAT → enter Public IP, Private IP, and corresponding protocol, then save.
Or in OpenWrt, use DNAT+SNAT rules: iptables -t nat -A PREROUTING -d Public IP -j DNAT --to-destination internal IP; iptables -t nat -A POSTROUTING -s Internal IP -j SNAT --to-source public IP.

6.

Routing and policy routing (multi-WAN or multi-IP scenarios).

If there are multiple public IPs or multiple WAN, configure policy routing to allow specific internal IP traffic to pass through the specified public network:
Steps: Create a new routing table (/etc/iproute2/rt_tables Add entries), add an ip rule to specify the source IP to use the table, then add an ip route in the table to point to the WAN gateway.
OpenWrt can be installed with mwan3 or operated using ip rule/ip route.

7.

Firewall, NAT, and security settings

For mapped internal hosts, open required ports on the firewall, while other unused ports remain blocked.
When configuring NAT rules on the router, be sure to set the corresponding INPUT/FORWARD rules and restrict source IPs or use VPN connections for management channels.
Regularly update the router firmware and back up your settings.

8.

Verification and troubleshooting steps

Verification steps: Ping the public IP from an external network (you can turn off Wi-Fi on your phone) and perform telnet/nc tests on the host's service port; Run traceroute and tcpdump -i wan on the internal network to check if the packet has arrived.
Frequently Asked Questions: 1) Gateway or Netmask settings are incorrectly→ preventing external network connection; 2) ISP must be bound to a specified MAC → Router WAN MAC must be modified; 3) Firewall Blocking → Check FORWARD/INPUT rules.

9.

Backup, monitoring, and common operational recommendations

Once completed, immediately export the router configuration file as a backup; Enable system logs and internal host monitoring (Zabbix/Prometheus or simple scripts) to detect anomalies.
For commercial services, it is recommended to apply for a fixed IP SLA or use dual redundancy, and regularly test the failover process.

10.

Q: What are the most important settings for the ISP's static IP address on the router?

Answer: The most important things are IP address, subnet mask, default gateway, and DNS. If the ISP specifies that binding with a MAC is required, the MAC must also be modified on the WAN interface; If using PPPoE mode, you need to set both the account password and static IP address (or confirm whether the ISP should assign them via dial-up).

11.

Q: How do you fully allocate a public IP to internal hosts (non-NAT)?

Answer: For general home use, 1:1 NAT is commonly used, or the router is set to Bridge so that the public IP can go directly to the internal host. A fully public, non-NAT method requires ISP assistance to point the IPRoute/ARP to your device, or set the CEC router as a bridge and have internal machines perform PPP/Static configuration.

12

. Q: What are the common checklists for internet inability after setting up?

Answer: Check whether the WAN IP is the address provided by the ISP, whether the Gateway is correct, whether the Netmask is consistent, whether the WAN interface is UP, whether the routing table has default routes, whether the router is blocked by the firewall, and whether the ISP has bound MAC or has not yet released a new IP. Use ping/traceroute/ip addr/ip route/tcpdump to check item by item.