[RB5009] IPv4 PPPoE Download Slow — CPU0 Maxed, IPv6 Fine, Full Speed Only After Factory Reset

I wonder there are way to read .backup and edit?

but I do this method seem fixed it.

  1. I dump into .rsc file
  2. factory reset
  3. use quick set (defconf remain)
  4. configure basic stuff like IPv6, Cloud, DoH, disable fasttrack (need use queue), etc
  5. test speed, 2G/1G as expected
  6. reboot
  7. test speed, 2G/1G as expected
  8. backup (just in case)

now edit .rsc file, remove what already exist (sanitize), re arrange line who take precedence, for example: add address list first before add filter/nat that use address list.
hard part like Wireguard, BGP, Routing, Port Forward, etc will be restore via SSH (paste all line)
then I reboot

verify all SD-WAN IPIP/IPIPv6 tunnel works, BGP, Route etc…

Then do speedtest again, this time, no weird speed drop, achieve 2Gbps download and 1Gbps upload on both IPv4/6 with Queue Tree active and fasttrack disabled:
Screenshot 2025-06-10 014633.png
This make me wonder, what inside of .backup file? Contain hidden internal states?