First of all, I'm not suscribet to the list, so please CC: me on an answres, please. I have a self built Linux router with a wifi card that I had setup a year ago or more as an AP. I worked for some 8 months without an issue, until a few months back (I have no date) it just stooped working. It took me a while to look into it, but finally today I got it working on channel 44 on the 5GHz band. I chose that channel because it was the only one available according to hostapd: nl80211: Mode IEEE 802.11a: 5180[NO_IR] 5200[NO_IR] 5220 5240[NO_IR] 5260[NO_IR][RADAR] 5280[NO_IR][RADAR] 5300[NO_IR][RADAR] 5320[NO_IR][RADAR] 5500[DISABLED][NO_IR][RADAR] 5520[DISABLED][NO_IR][RADAR] Because I got greedy, I wanted to keep configuring it to try to get 40GHz in the channel 46, but when I tried to run it again, I got: nl80211: Mode IEEE 802.11a: 5180[NO_IR] 5200[NO_IR] 5220[NO_IR] 5240[NO_IR] 5260[NO_IR][RADAR] 5280[NO_IR][RADAR] 5300[NO_IR][RADAR] 5320[NO_IR][RADAR] 5500[DISABLED][NO_IR][RADAR] 5520[DISABLED][NO_IR][RADAR] Channel 44 (primary) not allowed for AP mode, flags: 0x2073 NO-IR There was no package updates in between, they might have been some 5 to 10 minutes. The router was not rebooted, and has been connected to internet ever since I set it up initially a year ago. The country regulatory information is for France: nl80211: Regulatory information - country=FR (DFS-ETSI) nl80211: 2402-2482 @ 40 MHz 20 mBm nl80211: 5170-5250 @ 80 MHz 20 mBm nl80211: 5250-5330 @ 80 MHz 20 mBm (DFS) nl80211: 5490-5710 @ 160 MHz 27 mBm (DFS) nl80211: 57000-66000 @ 2160 MHz 40 mBm What could have happened, and could I somehow revert this? -- (Not so) Random fortune: The technology industry sees itself as in rebellion against corporate America: not corrupt, not buttoned-up, not empty. In fact, a tech company can be as corrupt, soulless, and empty as any corporation, but being unprofessional helps us maintain the belief that we are somehow different from Wall Street. -- Shanley Kane