Understanding Starlink Public IP Addresses

PURPOSE

To communicate how Starlink manages and delivers Public IPv4 and IPV6 addresses to active terminals.

BUSINESS OUTCOMES

• Efficiency & Productivity: Make informed decisions on how to configure and manage customer-owned routers connected to Starlink Flat High-Performance terminals activated with Business Priority Service plans as part of your Wide Area Network (WAN) solution.

IP ADDRESSES

1. IP Allocation:
   1. Each Starlink is allocated one IPv4 address and delegated a /56 IPv6 prefix for network clients. All Starlink network clients are assigned an IPv6 address if the router is IPv6 is capable. IPv6 is supported on all Starlink routers.
2. Default IP (CGNAT):
   1. The default IPv4 configuration is Carrier Grade Network Address Translation (CGNAT) using private address space assigned to Starlink clients using DHCP from the 100.64.0.0/10 prefix. Network Address Translation (NAT) translates between Starlink private and public IPs.
   2. The default IP policy using CGNAT blocks all inbound ports. Customers requiring inbound ports should consider alternate products with a public IP option. The following outbound ports are blocked for all customers per information security best practices: TCP/25 (SMTP) and TCP/445 (SMB).
3. Static IP and Mobile Users:
   1. Starlink does not provide static IP addresses currently. The Starlink network is dynamic and from time-to-time IP addresses will change for resilience, as network capacity increases, or when new countries are added to the network. 
   2. If you have a mobile Starlink the IP address may change if you move locations. These changes will cause a brief DHCP handoff outage. This is a fundamental limitation with how the internet works and is not a Starlink specific restriction. The internet is connected with stationary routers in data centers around the world to route traffic to the internet.
   3. Starlink is a global service and has many different routers in different locations to provide the lowest latency connection possible.
4. Public IP:
   1. The Starlink public IP policy is an optional configuration available to Priority, Mobile Priority, and Maritime business customers. A public IP is reachable from any device on the internet and is assigned to Starlink network clients using DHCP. Moving the Starlink to another location may cause the public IP to change. The public IP option can be enabled by contacting Simetry's24x7 helpdesk. 
   2. Public IP addresses are bound to the Starlink device for 24 hours regardless of the DHCP lease time. This ensures that if the Starlink device is rebooted or disconnected for less than 24 hours the IP address will not change. Additionally, if the Starlink device is offline for greater than 24 hours the IP address will remain associated to the Starlink device but becomes a candidate for reassignment if there are no other IPs available in the Starlink IP pool.
5. Using the Starlink WiFi router:
   1. If you use the Starlink WiFi router, IP addresses will be assigned to the Starlink router and the router will NAT all the client traffic towards your Starlink. The Starlink Gen2 WiFi router is compatible with IPv6 and will assign IPv6 addresses to compatible WiFi or wired clients. If you plan to use Starlink WiFi and ethernet dongle be mindful of double NAT issues!
   2. If you have a 3rd party router and a Flat High Performance Starlink, use the included Starlink Ethernet cable to avoid NAT issues.
6. Using a Third-Party Router: 
   1. For the High Performance dish, use the included Starlink Ethernet cable to connect from the Power Supply to the WAN port on your router. Recommended router configuration:
   2. DHCP : Configure the WAN port on the router to use DHCP to automatically get an IP address
   3. Health Checks: Relax heath checks (i.e. pings, etc.) to deal with occasional connection drops from Starlink. For example, checking every 10 seconds & getting 5 fails in a row would be a good threshold to start with.
   4. IPsec VPN: If your network is using an IPsec VPN please configure a "dynamic peer" for the device connected to Starlink.  
7. DHCP Lease Time:
   1. Starlink IP addresses are leased for 5 minutes at a time. However that doesn't mean your IP will change every 5 minutes. Starlink will try to maintain your IP for as long as the device is connected and has a public IP.
8. Geolocation:
   1. All Starlink IP Subnets and geolocation mapping and can be found in the Starlink Geo IP Database. The list of Starlink points of presence (PoPs) are maintained in PeeringDB