I have a router connecting my home LAN to the ISP. After opening port 8333 on the router, and forwarding it the computer running the node, bitnodes.io confirmed the node was reachable. However, bitnodes.io sees the IP address the ISP is currently assigning to my router on the trunk (Internet) side, which may change over time.
Do I need to ask my ISP for a static IP address, to be assigned to my router, trunk-side?
To run a Bitcoin full node you don't need to have a static IP address as when your IP address changes you should still be able to find peers and connect to them. However, if you want to maintain the same peers getting a static IP address is a good idea. Your connection to existing peers will drop if your IP address changes and you will either reconnect to them with your new IP address or connect to different peers. This isn't generally a problem because you are only receiving information on transactions and blocks from other nodes rather than in Lightning's case having funds locked up with them.
If you are planning to run a Lightning node it is much more important that you have a static IP address as you will have funds in a channel with another peer that identifies you using that IP address. Changing the IP address for your Lightning node poses greater challenges at this point.
