My Computer related stuff...

Airport Extreme, loosing WAN (adsl2 bridged) unnoticed on regular basis

in 2007, I bought an Apple Airport Extreme access point. This is connected with an ADSL modem to my ISP.
I discovered that at irregular intervals, the Internet connection would be lost, but the airport extreme would not discover this (the green led continues staring at me defiantly, even though the logging in the airport extreme would also indicate a line stating the apple ntp server could not be used to synchronize the time (whereas this synchronization is logged working fine some time before [logging states: Severity:5 Clock synchronized to network time server time.euro.apple.com (adjusted +0 seconds).]).


When I switched to ADSL2, these recurring hickups became more regular. Whenever these connection droppings occurred, a reboot (using the airport utility) of the base station (menu item "Base Station", option "Reboot") would fix the problem, after some reboot time (where the switch and airport functionality temporarily becomes unavailable (so network shares are lost, opened network files closed)) the network and the internet connection would become available again.
When replacing the airport extreme with a mac mini (and dhcp client on the mac mini activated), the internet connection (adsl2) becomes available, and is not dropped (for at least 6 days (2 test runs)).
Convinced this experience prooved the airport extreme was faulty, I contacted the apple store. There someone told me that the airport extreme must be faulty, but since the warranty period is over, the price for a repair would equal the price for a new device.

I bought myself a new time capsule, and replaced the airport extreme by it. The Internet is connected to the ADSL2 modem configured with bridging. The Time Capsule is configured to receive a DHCP response at WAN (which in fact is a fixed Internet Address). The Time Capsule also manages the local wifi with hidden ESSID and WPA2 encryption. The dhcp server in the time capsule provides configured addresses to potentially 5 LAN UTP clients, and 7 WIFI clients. Access control lists based on MAC address protects one small step further.

Although I'm happy with the increased switch speed (now 1000/100/10 instead of the 100/10MB), and the included 1TB time machine, the new machine displays the same unwanted behaviour. After about 2 to 4 hours, the Internet connection is lost without the access point discovering this loss. The access point A testrun again with the mac mini shows the mini not loosing connection (the mini however is not providing dhcp addresses to the intranet, which the extreme is).

I now run a script that at an interval tries to contact 5 websites. If all 5 consecutively fail to be contacted, an apple script is launched that will reboot the base station. These actions are logged, and show me the regularity of the failures:


20100101 165524 lost
20100101 170105 reboot
20100101 170556 OK
20100101 200953 lost [3h4m]
20100101 201533 reboot
20100101 202024 OK
20100101 220443 lost [1h45]
20100101 221009 reboot
20100101 221500 OK
20100101 234550 lost
20100101 235131 reboot
20100101 235623 OK

20100101 010000 suspended script
20100102 120000 launched script again

20100102 134558 lost
20100102 135138 erboot
20100102 135633 OK
20100102 161055 lost
20100102 161619 reboot
20100102 162107 OK
20100102 184857 lost
20010102 185437 reboot
20100102 185924 OK

This rebooting however is just a fixer,... always clears the logfile of the airport.

Labels: adsl2, airport extreme, apple, bug, hardware, network, wifi

posted by Dieter @ 20:41