@Sai340 I believe the problem is with your egress bandwidth minimum values that you're trying to set - try with bigger values. There's a thread which describes this error message - here.

@Idhaya As already has been mentioned, this router model is distributed by the ISPs. Here's a newer FW release for this router model. Keep in mind that if you upgrade the router FW, you may no longer...

@h-maulwurf As you already guessed the problem is caused by the Archer C6 NAT - details. Use this guide - Case 2 to configure Archer C6 in AP mode without changing its operation mode and check if you...

@Bigboobselephan This change should only affect the domain name resolution but not the router SPI Firewall - go through this story for more details.

@Feb There are more suitable device for that purpose like Archer C54 (with RE mode) or Archer C64 (with WDS) - both cheaper than VR400. You could ask your retailer to swap the VR400 for one of these,...

@Feb No, that's not possible. You can't upload FW release created for one HW version to device with a different HW version: