MacBook Pro DNS lookups fail periodically

[hobbbz]

My girlfriend's MBP (2007) sometimes stops being able to find sites through DNS.

She'll be browsing just fine and then when she goes to hit a new site it will say "Looking up [web address]" in the status bar of her browser indefinitely.

She is still able to connect to the WiFi through our AirPort Extreme and if she restarts the base station it will work fine for her.

Sometimes this happens 4 or so times a day.

Has anyone experienced anything similar? Are there any details that would help diagnose this?

 

[Amdahl]

Have you run Airport Utility and checked if there are any updates for your Airport Extreme?

 

[lostngone]

Is this really a DNS problem or a basic connectivity issue? Can you ping and traceroute with ip addresses durning these outages?


1. Do the base-station logs show anything?
2. If you by-pass the base-station are the symptoms the same?
3. Are any other systems on this network having the same problem?
4. Does rebooting the computer help or only the APE?
5. Do you get your broadband from a cable modem or a PPPOE type connection like DSL?
6. Is this a secured wireless network, i.e. required password. What type WEP or WPA?

 

[hobbbz]

Is this really a DNS problem or a basic connectivity issue? Can you ping and traceroute with ip addresses durning these outages?


1. Do the base-station logs show anything?
2. If you by-pass the base-station are the symptoms the same?
3. Are any other systems on this network having the same problem?
4. Does rebooting the computer help or only the APE?
5. Do you get your broadband from a cable modem or a PPPOE type connection like DSL?
6. Is this a secured wireless network, i.e. required password. What type WEP or WPA?

Thank you for the insightful questions:

I'm on the latest firmware with the AEBS
Ping / Traceroute only work inside the network and not outside, or atleast not outside named domains ( i didn't know any IP addresses off the top of my head to test)

1. See below
2. It's so random that I rarely have a chance to check before she just resets the AEBS since she knows that fixes it
3. No other systems regularly have this issue although it has happened once or twice
4. Haven't tried that
5. Cable modem -> AEBS
6. WPA

Logs:

Luckily while I was typing this it went down for her MBP and mine. I copied the logs below. It went down right around 13:00 then while i was messing around looking at logs it came back up

Jan 04 12:52:29	Severity:5	Installed unicast CCMP key for supplicant 00:0a:95:f4:5d:28
Jan 04 12:52:59	Severity:5	Connection accepted from [fe80::20a:95ff:fef4:5d28%bridge0]:51491.
Jan 04 12:53:03	Severity:5	Connection accepted from [fe80::20a:95ff:fef4:5d28%bridge0]:51492.
Jan 04 12:53:03	Severity:5	Connection accepted from [fe80::20a:95ff:fef4:5d28%bridge0]:51493.
Jan 04 12:56:01	Severity:5	Disassociated with station 00:0a:95:f4:5d:28
Jan 04 12:56:01	Severity:5	Rotated TKIP group key.
Jan 04 12:58:08	Severity:5	Associated with station 00:1b:63:d9:be:3a
Jan 04 12:58:08	Severity:5	Installed unicast CCMP key for supplicant 00:1b:63:d9:be:3a
Jan 04 13:00:46	Severity:5	Connection accepted from [fe80::219:e3ff:fe06:11d7%bridge0]:51377.
Jan 04 13:00:48	Severity:5	Connection accepted from [fe80::219:e3ff:fe06:11d7%bridge0]:51378.
Jan 04 13:00:48	Severity:5	Connection accepted from [fe80::219:e3ff:fe06:11d7%bridge0]:51379.
Jan 04 13:02:37	Severity:5	Internet Configuration leased -- host <68.184.202.24/255.255.240.0> gateway <68.184.192.1> dns <24.217.0.5 24.217.201.67> wins <> lease <28761> domain <>

Jan 04 13:03:00	Severity:5	Disassociated with station 00:1b:63:d9:be:3a
Jan 04 13:03:01	Severity:5	Rotated TKIP group key.
Jan 04 13:03:02	Severity:5	Connection accepted from [fe80::219:e3ff:fe06:11d7%bridge0]:51437.
Jan 04 13:03:04	Severity:5	Connection accepted from [fe80::219:e3ff:fe06:11d7%bridge0]:51438.
Jan 04 13:03:04	Severity:5	Connection accepted from [fe80::219:e3ff:fe06:11d7%bridge0]:51439.

 

[lostngone]

Ok, I guess first thing to check is connectivity. Write down a couple of ip addresses and keep them handy for the next failure.

If you can't get out at all then you need to make sure this isn't Base-station problem, you can just plug directly into the cable modem for a few days and see if this isn't just a cable modem problem. Some cable modems have management ip's and you just type into your web brower an address like 192.168.100.1(this address may not work for your modem) and get the status of the modem. If would also be a good idea to call the cable company and have them check the levels on the cable modem.


If it isn't a connection problem go into terminal.app you can find if you go to the Applications folder and then utilities folder.

Type into the terminal window.

cat /etc/resolv.conf

You should see two lines starting with the word "nameserver"

Looking at the logs you sent they should be 24.217.0.5 and 24.217.201.67.

You should be able to then be able to use telnet to test the connection to the DNS servers type in what ever address is in the resolv.conf followed by 53

telnet 24.217.0.5 53

and get something like this... Try both address
__________________________________________
207-218-58-55:~ lostngone$ telnet 24.217.0.5 53
Trying 24.217.0.5...
Connected to vip1olvemo.stls.mo.charter.com.
Escape character is '^]'.
__________________________________________


You can also try the dig command during a failure and see if you get an output that looks like the following...

__________________________________________
207-218-58-55:~ lostngone$ dig

; <<>> DiG 9.4.2-P2 <<>>
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 64387
;; flags: qr rd ra; QUERY: 1, ANSWER: 13, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;. IN NS

;; ANSWER SECTION:
. 349001 IN NS g.root-servers.net.
. 349001 IN NS k.root-servers.net.
. 349001 IN NS j.root-servers.net.
. 349001 IN NS l.root-servers.net.
. 349001 IN NS h.root-servers.net.
. 349001 IN NS m.root-servers.net.
. 349001 IN NS i.root-servers.net.
. 349001 IN NS f.root-servers.net.
. 349001 IN NS c.root-servers.net.
. 349001 IN NS e.root-servers.net.
. 349001 IN NS a.root-servers.net.
. 349001 IN NS d.root-servers.net.
. 349001 IN NS b.root-servers.net.

;; Query time: 10 msec
;; SERVER: 209.165.131.12#53(209.165.131.12)
;; WHEN: Sun Jan 4 13:47:56 2009
;; MSG SIZE rcvd: 228
__________________________________________



I have had a problem like yours but it turn out to be my ISP's crappy DNS servers. It took 3 weeks of calling then to finally to get them to admit they were having name resolution problems. I used these guys until they got the problem fixed.

http://www.opendns.com/

 

[hobbbz]

So after months of investigating I've determined that the AEBS is just holding on to its DHCP lease for too long and the cable modem is dropping it when it gets a new lease.

Does anyone know of a way to make the AEBS keep its leases from the cable modem for shorter periods of time?
(not give shorter leases to its clients)

 

[hobbbz]

To help myself and others here's an update:

Same problems as before.
I've had the cable guy out to check the lines, he said they were fine.

I replaced the modem with a Motorola SurfBoard, seemed to be ok for about a day but had a drop out.
I searched Google with the log error, and came up with this:

http://forums.whirlpool.net.au/forum-replies.cfm?t=836026

which told me to switch the IPV6 to Local-Link only whatever that means.

 

[hobbbz]

More update news!

I did a hard reset of the AEBS and all is well. It never has had a glitch again. I know I should have tried this about 11 months ago but I didn't want to lose all my settings.