Tabouli
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Q: MacBook Air loses connection to internet but not LAN

Hi, I am using a MacBook Air 11" (mid-2012) running OS X Mavericks (10.9.3). I'm connecting to my home LAN via WiFi connection to a TP-Link 300M Wireless router that is setup as a switch (per instructions here http://www.tp-link.com/en/article/?faqid=417), which in turn is connected via wire (ethernet-over-power) to a Technicolor cable modem/router provided by my ISP (UPC in the Netherlands; I can look up the model number of the router if needed, but it's two floors down right now and doesn't strike me that this is the cause of the problem).

 

I have a problem that my MacBook Air intermittently loses connectivity to the internet for extended periods (minutes) even though (a) the MacBook Air maintains full connectivity to my LAN at the same time through WiFi and (b) other computers connected to the cable modem/router maintain their connection to the internet while my MacBook Air has lost its connection.

 

My test to see where the breakdown is occurring is to have four terminal windows up and running ping processes:

 

1) ping to 192.168.0.1 (my router) - this always stays live, with essentially no lost packets

2) ping to an external address (I'm using 74.125.136.94, a google.nl address) - this is my main test for access to the internet and where I see ping failures (I'm also testing with pings to other sites when the problem is occurring to ensure it's not something on the remote end).

3) ping to 192.168.0.13, which is a Synology NAS attached via ethernet cable to my main cable modem/router - this always stays live, with essentially no lost packets.

4) a login to the Synology NAS, where I am also running a continual ping to 74.125.136.94, and this external ping does NOT fail when the one from my MacBook Air does, it stays live with essentially no lost packets.

 

The problem will usually correct itself after 1-3 minutes (though the time is not consistent), and also gets corrected if I turn the MacBook Air's WiFi off and on again.

 

Any suggestions for what I can do to stop this problem?

 

Thanks

John

MacBook Air (11-inch Mid 2012), OS X Mavericks (10.9.3)

Posted on Aug 22, 2014 8:26 AM

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Q: MacBook Air loses connection to internet but not LAN

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  • by Linc Davis,

    Linc Davis Linc Davis Aug 22, 2014 11:48 AM in response to Tabouli
    Level 10 (207,941 points)
    Applications
    Aug 22, 2014 11:48 AM in response to Tabouli

    Do you have the same problem when connecting to other networks?

  • by Tabouli,

    Tabouli Tabouli Aug 22, 2014 12:13 PM in response to Linc Davis
    Level 1 (0 points)
    Aug 22, 2014 12:13 PM in response to Linc Davis

    I can't rule it out conclusively, but I haven't noticed a problem when on other networks.

     

    In fact, when I am connected via wifi directly to my cable modem/router, I do not have the problem, only when I am connected to the secondary router acting as a switch. (But since the secondary router acting as a switch is still allowing me to connect the cable modem/router, I'm thinking it's not a problem with that switch itself but rather the Mac. I guess I will test this out with a second computer running alongside mine and/or connecting my NAS to the switch rather than the cable modem/router.)

     

    (And to clarify, 192.168.0.1 is my cable modem/router).

     

    JB

  • by Linc Davis,

    Linc Davis Linc Davis Aug 22, 2014 12:30 PM in response to Tabouli
    Level 10 (207,941 points)
    Applications
    Aug 22, 2014 12:30 PM in response to Tabouli

    It sounds like what you want is a roaming network. I can't tell you how to set that up with third-party equipment. Refer to the documentation.

  • by Loner T,

    Loner T Loner T Aug 22, 2014 1:10 PM in response to Tabouli
    Level 7 (23,663 points)
    Safari
    Aug 22, 2014 1:10 PM in response to Tabouli

    1. What happens when you turn off the TP-LINk (and it's wifi)? Can you connect to the Technicolor WiFi and stay connected?

    2. The TP-Link disables DHCP according to the document link you provided, but you may want to double check for IP conflicts or overlapping DHCP server configurations.

    3. If you change the Technicolor to a fixed 2.4G channel, and the TP-Link to another 2.4G channel, where the two channels are at least two channels apart, do you still have the same problem?

    4. If you Alt-click on the MBA WiFi icon and run Wireless Diagnostics -> Command+2 for Utilities menu, can you run Scanner and Performance functions to see any RF drops?

    5. Are you using the same wifi SSID for both TP-Link and Technicolor?

    6. It may be helpful to know which Technicolor TC model you are using?

  • by Tabouli,

    Tabouli Tabouli Aug 26, 2014 2:42 AM in response to Loner T
    Level 1 (0 points)
    Aug 26, 2014 2:42 AM in response to Loner T

    Loner,

     

    Your questions seemed to be rooted in a notion that there is a problem with the wifi connectivity. There is none. The MBA stays connected to the WiFi solid as a rock, and the MBA can communicate within my LAN via wifi at all times. The issue is that intermittently, with no readily apparent cause, the MBA loses connectivity with the outside world (i.e., the Internet) while other computers on the LAN stay connected to the Internet.

     

    Do you have other suggestions?

     

    JB

  • by Tabouli,

    Tabouli Tabouli Aug 26, 2014 2:44 AM in response to Linc Davis
    Level 1 (0 points)
    Aug 26, 2014 2:44 AM in response to Linc Davis

    Linc: By roaming network, I take it you mean to use the secondary access point as a bridge rather than as a switch using a separate SSID? Why would that be helpful?

     

    For what it's worth, I upgraded to 10.9.4 and I still had this problem today.

     

    JB

  • by Loner T,

    Loner T Loner T Aug 26, 2014 4:39 AM in response to Tabouli
    Level 7 (23,663 points)
    Safari
    Aug 26, 2014 4:39 AM in response to Tabouli

    Have you tried #4?

     

    Also, switch off WiFi on the MBA, use an ethernet connection to the TP-Link (if necessary, via an adapter), and re-run the test.

     

    The MBA is periodically looking for new APs, even though it is connected to an existing network.

     

    A Roaming network has multiple wired APs connected to backend broadcasting the same SSID, so devices can be mobile, using SSID scanning function.

  • by poziom-k,

    poziom-k poziom-k Aug 27, 2014 10:42 AM in response to Tabouli
    Level 1 (0 points)
    Aug 27, 2014 10:42 AM in response to Tabouli

    Tabouli,

     

    It seems we are both facing the same issue (at least the symptoms are exactly the same). I also have UPC (Poland) with Technicolor TC7200. I am using Airport Time Capsule though.

    I created this topic yesterday ATC dropping WAN connectivity

  • by Tabouli,

    Tabouli Tabouli Sep 1, 2014 6:27 AM in response to poziom-k
    Level 1 (0 points)
    Sep 1, 2014 6:27 AM in response to poziom-k

    Yes, poziom-k, this does look like the same problem. I am (slowly) doing further testing here to try to pinpoint this to the MBA, the second access point, or the interaction of the two (though I strongly suspect it's the MBA). Please let me know if you've made any progress on solving your problem. -John

  • by poziom-k,

    poziom-k poziom-k Sep 3, 2014 1:03 PM in response to Tabouli
    Level 1 (0 points)
    Sep 3, 2014 1:03 PM in response to Tabouli

    I've tested another router (some old ASUS) and the symptoms are the same. It seems that the combination of MacBook, Technicolor from UPC and additional access point cause the problem.

  • by Loner T,

    Loner T Loner T Sep 4, 2014 3:35 AM in response to poziom-k
    Level 7 (23,663 points)
    Safari
    Sep 4, 2014 3:35 AM in response to poziom-k

    1. If the MBA is connected to the

         a. the Technicolor SSIDs, is the behavior the same (poziom-k testing shows that a second AP causes problems).

         b. can the Technicolor be replaced easily by an Airport Express/Extreme, to repeat this test?

    2. Instead of WiFi, if the MBA is cabled to the secondary AP, is the behavior the same?

    3. Has Wireless RF interference been ruled out for dropped connections?

    4. If the MBA has a wired connection to the Technicolor, does the problem still exist?

    5. Have packets been captured at each interesting point in the topology to see where are packets drops occurring? netstat -s is probably worth looking at such points. Wireshark (or similar tools) can help.

    6. I have seen Cisco APs send "disassociate" messages to wifi equipment.

  • by poziom-k,

    poziom-k poziom-k Sep 4, 2014 12:52 PM in response to Loner T
    Level 1 (0 points)
    Sep 4, 2014 12:52 PM in response to Loner T

    > 1. If the MBA is connected to the

    >     a. the Technicolor SSIDs, is the behavior the same (poziom-k testing shows that a second AP causes problems).

    No. If connected to WiFI served by Technicolor, the problem does not occur (even if the other AP is connected to the network).

     

    >     b. can the Technicolor be replaced easily by an Airport Express/Extreme, to repeat this test?

    Unfortunately, Technicolor in router mode is required by my ISP.

     

    > 2. Instead of WiFi, if the MBA is cabled to the secondary AP, is the behavior the same?

    Yes.

     

    > 3. Has Wireless RF interference been ruled out for dropped connections?

    Yes. A Windows machine and several iOS mobile devices work flawlesly for me.

     

    > 4. If the MBA has a wired connection to the Technicolor, does the problem still exist?

    No. The problem occurs only if connected through additional AP.

     

    > 5. Have packets been captured at each interesting point in the topology to see where are packets drops occurring? netstat -s is probably worth looking at > such points. Wireshark (or similar tools) can help.

    Not yet. I will not have a chance to do it for the next few days though :/

  • by bit4net,

    bit4net bit4net Sep 4, 2014 1:03 PM in response to poziom-k
    Level 1 (0 points)
    Sep 4, 2014 1:03 PM in response to poziom-k

    can you install Packet Peeper on your MBA and make a capture of your network traffic in both situations?

    a) working ping to uncle Google

    b) packet dropping ping to uncle Google

    a trace route might also be giving some more info as it looks like a network error at some point. may be in the MBA nic stack? is there any IPv6 active on your network?



  • by Loner T,

    Loner T Loner T Sep 4, 2014 8:12 PM in response to poziom-k
    Level 7 (23,663 points)
    Safari
    Sep 4, 2014 8:12 PM in response to poziom-k

    poziom-k wrote:

     

    > 1. If the MBA is connected to the

    >     a. the Technicolor SSIDs, is the behavior the same (poziom-k testing shows that a second AP causes problems).

    No. If connected to WiFI served by Technicolor, the problem does not occur (even if the other AP is connected to the network).

     

     

    > 2. Instead of WiFi, if the MBA is cabled to the secondary AP, is the behavior the same?

    Yes.

     

     

    > 4. If the MBA has a wired connection to the Technicolor, does the problem still exist?

    No. The problem occurs only if connected through additional AP.

    Tabouli's topology (TC7200 <-Ethernet Bridge-> TP-Link <-WiFi-> MBA), and yours (TC7200 <-Ethernet Bridge->ATC <-WiFi->MBA) is very similar.

     

    Given #2, you have an ethernet connection all the way to the TC7200 (no WiFi at all) and it does NOT work, but if you eliminate the ATC, you have no issues per #4. This problem is different than Tabouli's.


    In Tabouli's case, we do not know the results of the ethernet connection to the TC7200, but using #3 (Synology test), if the packets can get to the NAS via the TC7200 (on the LAN and can be forwarded via the WAN interface to google.nl as per Tabouli #4), the ATC and the TP-Link behave differently.


    Packet capture for specific source-destination pairs will be helpful to pursue either problem further.

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