Shortcomings
- Breaks P2P traffic.
- Increases latency.
- It leads to NAT-keep alive traffic (such as NAT punching, NAT traversal mechanisms etc) on end-users’ local network as well as on the CGNAT device itself.
- Which in theory could affect battery life on end-user devices.
- Increased link utilisation/CPU cycles on the CGNAT device.
- Some end-user applications will simply refuse to work or fail miserably like Xbox Networking (P2P Gaming services), Torrent clients etc.
- Lacks NAT traversal mechanisms/port forwarding (by default).
My ISP:
If you have a valid reason and need to opt-out of CGNAT you can call our technical support staff
“I’m running 500 nodes with 500 peers”…is not going to cut it…
Static IP:
So we rent an IPv4 address for AUD$5 @ month which results in us bypassing the CGNAT infrastructure. Because I’m on FTTC, the protocol dictates DHCP for the WAN port…so no action required by the customer.
The clincher:
I could never get port forwarding to work…I was a reluctant --home-network runner
No longer! I now get moar chunks and a healthy peer list…but here’s the kicker…
- I have NO Port Forwarding rules set on the router
- NO --home-network
- NO --upnp
- I do specify udp port ranges, which is probably best practice.
- Internet performance is also improved
- The node machines Ethernet graph appears more ‘bursty’
Summary
I don’t know how this is working without port forwarding, but could be a big plus for network/ router performance if we can get most node runners on Static IP.
I’m sure it would benefit ISP’s to have node runners bypass CGNAT also…at scale it has to affect their other customers.
I wonder if Digital Ocean have similar NAT config that impacts performance.