I have the DIR-655 router (hardware version A3) and it has had firmware version 1.21 for a while. I resisted upgrading it to 1.3x versions because of the warning that version downgrade to 1.2x was not allowed from those versions. Further, I had read reports of issues faced by people and recommendations for staying at 1.2x if there were no problems.
Recently, I started encountering network issues which were more like annoyances than real issues. I did a little bit of research and then decided to try a firmware upgrade on the router. I backed up the router configuration and upgraded the firmware to 1.34NA using the file name
DIR655A4_FW134NAb03.bin. The A4 in the name made me hesitate a bit since my hardware version is A3. However, I could not find any information regarding the hardware version differences with regard to this firmware version. The upgrade seemed to go fine and I reset it to factory defaults using the admin application, as recommended. However, I was unable to reload the backed up configuration as it was being considered as corrupted. So I went ahead and repeated the configuration manually.
I have been pleasantly surprised by the ease of upgrade and the improved features and performance. I haven’t tried all the new features yet but I browsed through and liked what I saw. Since I have seen so many horror stories in this regard I wanted to share this experience for those who may be considering a similar upgrade.
[UPDATE] Today, the wireless functionality suddenly started giving problems. Incidentally, I was messing with firewall settings on a Linux box just before that. I couldn’t see a relation between the two. I restored the settings to factory defaults and edited settings manually but continued to face problems. Then I recalled reading about disabling DNS relay for the 1.3x firmware somewhere. I unchecked Enable DNS Relay on Setup > Network Settings and that resolved my problems.