MacBook Pro Wireless Connection Issues

Could this be a result of something happening with the Time Machine backup? Have you tried disabling that?

Afraid not, Roybridge. I don't own a time machine, and it's disabled on this MacBook.

Can you try using an RJ45 cable directly to your router to see if it happens on the Ethernet connection too?

Another thing to try is disabling the N mode on your wireless router...

I've tried that as well. It happens even on G

And with the cable?

Also, take a look at some of the suggestions at http://www.switchingtomac.com/tutorials/osx/macbook-pro-constantly-dropping-wireless-connection/

With a cable, it's fine. Some of the suggested methods I've tried, others seem a bit drastic (taking it for a repair or doing a full wipe) yet which is why I wanted to see if anyone here knew of this.

Is there a firmware update for your Mac at all? Also, it may be worth taking to an Apple shop - it appears that LOADS of people have experienced Wi-Fi problems with their MBPs and Apple have replaced some because of this issue.

Even if you MBP is out of Warranty, Apple may still do something as it's a widely know issue.

do you have other machines using that same wifi connection ? do they have the same problem ?
did you try another wifi connection with your mac ? do you have the same problem ?

did you try rebooting the wifi box ? do you still have the same problem ? at the same time as previously ?

Skullnobrains: I have about 7 other devices here, both wired and wireless, none of which experience this issue. Also, as far as having the same issue on other wireless networks, I don't spend enough time on other connections to have an answer, however I can say that I've changed routers three times now, between three different brans to remedy this, and the issue still persists.

I have power cycled all that I can, and I've tried creating a new connection profile on the mac in case old profiles were the problem. I even tried restting the Mac SMC.

Open Activity Monitor, found in /Applications/Utilities and see if there is some application or process that starts to run which coincides with your connectivity problem on the 13 minute make.

Is you Mac set to DHCP or to a fixed address?

Is your router secured with WPA? Is there a possibility of someone accessing your network from outside?

Also are there any devices on your network with fixed IP addresses?

Also, open the Console utility and check your logs to see if there is any suspicious activity at the 13 minute mark of the hour.

ok, so i think we can assume that
- this would happen on any wireless network
- this would happen at :13 regardless of the time the machine was powered on
- same as above regardless the time a specific process was manually started

let's try to find if a specific process starts at :13 each hour. count be an antivirus update scheduled a while before for example. there may also be some external interference that messes with the wifi of this specific machine

i'm curious about a couple of things
- do you have the same problem if you plug a cable instead of using the wifi ?
- do you have an antivirus or firewall software ?

you can look at cron to see what scheduled tasks you have on this machine

is the model of your wifi card specific ? does it use a different channel than the other devices ? you can see most wifi-related information through ifconfig

Having read the Apple forum (one post relating to this was over 103 pages long), I'm convinced that the problem is probably a hardware fault.

Which thread was that? Can you post a link? I am aware of complaints of random dropping of the internet connection, but not of regular hourly dropping.

i don't see why a hardware problem would occur at :13
maybe if it occured every 65k seconds after the machine was booted or something similar
also interested in the thread, please

I'm going to let this happen a few times while carefully watching the system console. If I can get at least two events and capture something consistent that coincides with each drop that I can see in the logs, I'll paste it here.

can you answer my questions, please ?
also did you look at the crontabs ?

Keep Activity Monitor open at the same time with the column sorted by CPU%

I had this issue too with Macbooks on a Zyxel Accesspoint. Windows and even iphone and ipad  was ok. I changed the Access point and never had this issue since then. it looks for me, that not all Wifi Products are working well with Macs. I have a Timecapsule now.

I just don't.understand why it always happens on.the 12th or 13th minute of any hour that it occurs. Wouldn't you know it, since I've decided to keep an eye on it, it hasn't happened yet.

It happened, and this was the only message to the console:

sandboxd: Trillian(5567) deny network-outbound 192.168.1.154:54750

Now trillian is my messenger application, but all of my other applications also dropped their connections at the time this showed up. Though I'm not sure if this has anything to do with anything, the full report for this event is as follows:

Trillian(5567) deny network-outbound 192.168.1.154:54750

Process:         Trillian [5567]
Path:            /Applications/Communications/Trillian.app/Contents/MacOS/Trillian
Load Address:    0x1000
Identifier:      Trillian
Version:         ??? (???)
Code Type:       X86 (Native)
Parent Process:  launchd [214]

Date/Time:       2012-11-12 10:03:33.932 -0600
OS Version:      Mac OS X 10.7.5 (11G63)
Report Version:  7

Backtrace:
0   libsystem_kernel.dylib              0x9339bc22 __sendto + 10
1   libsystem_c.dylib                   0x904db467 send$UNIX2003 + 54
2   core.dylib                          0x0a30b853 SEDA::CSocket::Send(unsigned short, unsigned long, char const*, int, int&) + 177
3   core.dylib                          0x0a30eefc SEDA::CWriteEvent::Execute(SEDA::CNetworkStage*) + 356
4   core.dylib                          0x0a3009c3 SEDA::CNetworkStage::Run() + 393
5   core.dylib                          0x0a30cd9f InvokeThread + 17
6   libsystem_c.dylib                   0x90526ed9 _pthread_start + 335
7   libsystem_c.dylib                   0x9052a6de thread_start + 34

Binary Images:
 0xa247000 -  0xa365fff +core.dylib (??? - ???) <051DA009-98D7-360D-A70B-12DE820E5F80> /Applications/Communications/Trillian.app/Contents/MacOS/core.dylib
0x904ca000 - 0x90595fff  libsystem_c.dylib (763.13.0 - compatibility 1.0.0) <52421B00-79C8-3727-94DE-62F6820B9C31> /usr/lib/system/libsystem_c.dylib
0x93383000 - 0x933a1ff7  libsystem_kernel.dylib (1699.32.7 - compatibility 1.0.0) <79179F83-457A-3539-A76B-E960D2108109> /usr/lib/system/libsystem_kernel.dylib

Hard to say whether this is the cause or effect of the disconnection. Do you have a different IM client you  could try instead for a while?

I think its the latter. It happened twice, but the second time there was nothing in the console, nor did any application run at that time or hit the top of the process list while sorted by CPU usage. I'm at a loss here.

It may very well not be caused by anything internal to the Mac. There are several external possibilities.

One is interference from another wireless device like a cordless telephone or microwave.

Another possibility is that something on your network is poaching the Mac's IP address temporarily.  Are there any devices on your network that might connect to the network periodically?

A third possibility is something connecting from outside your network if your network is not properly secured.

Depending on what type of router you have, you might try checking the router logs for activity at the same time the Mac dies.

This is my third router, each has been for a different manufacturer. I have no cordless or.wireless devices here that work on 2.4 ghz or 5 ghz that would be messing with my wifi, and the drops take place when the microwave isn't in use

I've tried changing wireless channels anyway, just to be safe, but with no positive results. Not sure what to make of it at this point, but looking elsewhere, its apparent that many MacBook Pros like mine are rife with wifi connectivity issues. This is pretty disappointing. Also, each of my routers have been secured with WPA2 encryption, and nothing simple. Its not an IP or MAC conflict at all.

Maybe I should just call a priest at this point.

Do you have any router logs you can check?

BTW, there are similar complaints on some Trillian forums.  Try googling https://www.google.ca/search?rls=en&q=trillian+kills+internet

That is why I suggested trying another IM client.

BTW, when this happens you say you can't ping the internet. Are you pinging by IP or by URL? If you can still ping by IP, then you know it is a DNS problem.

What DNS servers do you have set in the Mac network prefs for the wireless interface?

You could try experimenting by adding the Google public DNS servers:

8.8.8.8
8.8.4.4

One more thought. Go into your network prefs and make a note of the IP address of the MacBook wireless interface. Then after you have one of these episodes and the Mac reconnects, see if the IP address has changed.

If it has, check the router logs to see if something else is now using the MacBook's previous IP address.

BTW, what brand and model is your router?

I have already tried the DNS fix with Google's public DNS servers but that didn't help at all. Plus, when this does happen I can't ping public IPs beyond my home network, so its not a DNS resolution issue. Its just as if that Mac will no longer pass traffic at all. As far as the question about having a different IP, its not like the router is rebooting and dropping my lease. The wireless connection never drops at all, and I retain the same IP address. But I have no connectivity, while my other devices show no signs  of losing their connections nor do they have any trouble loading pages or remaining connected to remote servers or VPN sessions. And this time around, the wireless that I'm using is from my Motorola router/cable modem. Still, as I mentioned before, this issue persists across three brands. Net gear. Linksys. And now this one.

Long shot, but have you run a scan for Trojans? Here is a free one:  http://www.sophos.com/en-us/products/free-tools/sophos-antivirus-for-mac-home-edition.aspx

Another long shot, but worth a try. Try setting your Mac to a fixed IP address which is on the same subnet as your router, but outside the range used by the DHCP server, say, 192.168.1.250. Don't forget to supply the DNS IP's and gateway manually as well.

Do you think something is being assigned on top of my IP? Or something else might be set static to the same IP I'm given? Because I can assure you I'm pretty meticulous when it comes to my network. On top of that, most modern OSs are pretty good about warning you if there is an IP conflict, especially Macs. Still, I will give it a try and see what comes of it. I travel often with this thing, so I don't look forward to constantly switching profiles or changing these settings when I'm abroad, so part of me hopes this isn't a solution. Still, I'll mention again that I don't lose any of my IP configs when this happens. One thing I haven't tried is to ping the actual router when it occurs, so I'll try that as well. If I can, but can't ping beyond it, while all of my other devices can, then that ... would be even more confusing, actually. I'll let you know.

I am sort of grasping at straws. You have very strange symptoms, and my thoughts are that possibly something else is grabbing the MacBook's IP. Alternatively, you may have a trojan.

If it never happens when you are traveling, that points to something on your network.

I appreciate that you are meticulous with your IP's, but if you have a number of devices on your home LAN (as I do!) it is easy enough to forget one (AppleTV, printer, scanner, iPod, network storage, who knows what else.)

Does your router have a logging function so you can see what is logged into it wirelessly?

I am a network administrator by trade, and I use Fing to keep accurate lists of all my networks, including my home network. I do have software that arp pings my network for new devices, and nothing stands out there.

Okay. I am almost out of ideas, other than checking the router logs

please anwser my previous questions and follow these debugging steps

next time you have the problem, do the following while watching the console
- flush your arp cache (command should be "arp -da")
- ping your router and tell us the results
- display your arp cache and post the results
- if the ping worked, please repeat the previous for another machine on the same local subnet
- also do a traceroute to an external address. check your routing table manually if you can. post the output of "route -r" if possible
- if you don't mind, also post the output of ifconfig

i believe the trillian issue to be a consequence and not a cause
but a bad UPNP query may kill the wifi connection

Strung: it happened again, even with all IP setting being static.

skullnobrains: I answered your question before you asked. This issue does not occur when plugged in directly. I also do not have any firewall or antivirus software on the Mac. It's mainly used for development and reading Cracked articles.

As far as the pings go, while all other devices on the network continue to work fine and route to the internet, the Mac can't ping external IP addresses. However!!!!! I did test some pings to my router this time, and though my pings wouldn't seem to route out and reach places on the net, they WOULD reach the router.... I don't have time this morning but I will give your suggestions a try this evening, skullnobrains.

Alright. Happened again. This time, while it was not routing again, I checked to see if 192.168.1.1 was still accessible through a browser, and it loaded fine and allowed me to browse through different menus on the router. Anything beyond on the net, however wouldn't load. Second thing I did was I delete my arp cache as you asked and once again was able to ping out. That concerns me a bit.

Here is my routing table for the Macbook. I hope this posts properly:

DevMBP:~ kbrackin$ netstat -nr
Routing tables

Internet:
Destination        Gateway            Flags        Refs      Use   Netif Expire
default            192.168.1.1        UGSc           30        9     en1
127                127.0.0.1          UCS             0        0     lo0
127.0.0.1          127.0.0.1          UH              4    24623     lo0
169.254            link#4             UCS             0        0     en1
192.168.1          link#4             UCS             6        0     en1
192.168.1.1        94:cc:b9:28:e0:32  UHLWIi         27        0     en1   1077
192.168.1.75       127.0.0.1          UHS             0        0     lo0
192.168.1.153      5c:a:5b:17:33:e6   UHLWIi          0        2     en1   1109
192.168.1.156      44:6d:57:4b:d9:a6  UHLWIi          1        2     en1   1195
192.168.1.255      ff:ff:ff:ff:ff:ff  UHLWbI          0        3     en1

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And my arp table…

DevMBP:~ kbrackin$ arp -a
? (192.168.1.1) at 94:cc:b9:28:e0:32 on en1 ifscope [ethernet]
? (192.168.1.153) at 5c:a:5b:17:33:e6 on en1 ifscope [ethernet]
? (192.168.1.156) at 44:6d:57:4b:d9:a6 on en1 ifscope [ethernet]
? (192.168.1.255) at ff:ff:ff:ff:ff:ff on en1 ifscope [ethernet]

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Now from another machine which hasn't been affected, this is the ARP table after clearing its cache as well.

C:\Users\kbrackin>arp -a
Interface: 192.168.1.156 --- 0xb
  Internet Address      Physical Address      Type
  192.168.1.1           94-cc-b9-28-e0-32     dynamic

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And my route table on that machine…

C:\Users\kbrackin>netstat -nr
===========================================================================
Interface List
 12...e8 40 f2 b9 7c f2 ......Realtek PCIe GBE Family Controller
 11...44 6d 57 4b d9 a6 ......802.11n Wireless LAN Card
 20...08 00 27 00 a0 f3 ......VirtualBox Host-Only Ethernet Adapter
  1...........................Software Loopback Interface 1
 16...00 00 00 00 00 00 00 e0 Microsoft ISATAP Adapter
 13...00 00 00 00 00 00 00 e0 Teredo Tunneling Pseudo-Interface
 21...00 00 00 00 00 00 00 e0 Microsoft ISATAP Adapter #2
===========================================================================

IPv4 Route Table
===========================================================================
Active Routes:
Network Destination        Netmask          Gateway       Interface  Metric
          0.0.0.0          0.0.0.0      192.168.1.1    192.168.1.156     25
        127.0.0.0        255.0.0.0         On-link         127.0.0.1    306
        127.0.0.1  255.255.255.255         On-link         127.0.0.1    306
  127.255.255.255  255.255.255.255         On-link         127.0.0.1    306
      192.168.1.0    255.255.255.0         On-link     192.168.1.156    281
    192.168.1.156  255.255.255.255         On-link     192.168.1.156    281
    192.168.1.255  255.255.255.255         On-link     192.168.1.156    281
     192.168.56.0    255.255.255.0         On-link      192.168.56.1    276
     192.168.56.1  255.255.255.255         On-link      192.168.56.1    276
   192.168.56.255  255.255.255.255         On-link      192.168.56.1    276
        224.0.0.0        240.0.0.0         On-link         127.0.0.1    306
        224.0.0.0        240.0.0.0         On-link      192.168.56.1    276
        224.0.0.0        240.0.0.0         On-link     192.168.1.156    281
  255.255.255.255  255.255.255.255         On-link         127.0.0.1    306
  255.255.255.255  255.255.255.255         On-link      192.168.56.1    276
  255.255.255.255  255.255.255.255         On-link     192.168.1.156    281
===========================================================================
Persistent Routes:
  None

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Finally, the output for my wireless adapter in ifconfig:

en1: flags=8963<UP,BROADCAST,SMART,RUNNING,PROMISC,SIMPLEX,MULTICAST> mtu 1500
	ether 68:a8:6d:39:23:f6 
	inet6 fe80::6aa8:6dff:fe39:23f6%en1 prefixlen 64 scopeid 0x4 
	inet 192.168.1.75 netmask 0xffffff00 broadcast 192.168.1.255
	media: autoselect
	status: active

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ok, so we can rule out a wifi problem since you can access the router normally.

routing tables seem fine, and nothing you said suggest that they may be different during the time the problem occurs.

the difference in arp tables does not seem very strange if your macbook has a reason to chat with machines at 153 and 156 while the other machine has none or maybe did not get the chance after you flushed it's cache and before you read the table

i guess not resolving local host names is normal behavior on your lan so the "?" at the beginning of the table are ok.

--

now i'm confused because resetting the arp cache did solve the problem, meaning we're probably getting somewhere, but i really do not understand why any arp related problem would happen at :13 other than a rogue device sharing your arp getting into your network periodically.

i believe we can assume that resetting the arp and then pinging probably send an arp update so the faulty arp table can also be the router's OR you untriggered some security feature that went berserk because another device would try to connect to the wifi network with the same ip or arp you have. it is unclear why the router would refuse to route but answer pings in this case.

i'm interested in a few things, now
- what did the arp table look like BEFORE you flushed it ? same ?
- any security-related alerts on the router ? can you see the router's arp table ?
- does traceroute/ping show some error messages when you trace google while you can access the router and not the outside world (something like network-unreachable or no route to host ?)
- can you access other resources on your network ?
- on your lan but on a different network ?
- does it solve the problem if you simply change your MAC address ?

whatever the problem i really believe solving it would rely on doing as much debug as possible while the problem occurs.

--

also, i'm a little confused bu the SMART flag. anyone knows what this is ? something like smartscan for background scanning of wifi networks ?

Sorry for the delay on replying. Sorry for the line numbers on each of these when I use the code tags, I'm just trying to keep it in some sort of unicode font so the spacing and tab spaces are preserved for displaying. Here's my arp table before flushing after days of use:

? (192.168.1.1) at 94:cc:b9:28:e0:32 on en1 ifscope [ethernet]
? (192.168.1.153) at 5c:a:5b:17:33:e6 on en1 ifscope [ethernet]
? (192.168.1.156) at 44:6d:57:4b:d9:a6 on en1 ifscope [ethernet]
? (192.168.1.161) at b0:d0:9c:e6:bb:cb on en1 ifscope [ethernet]
? (192.168.1.255) at ff:ff:ff:ff:ff:ff on en1 ifscope [ethernet]

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Unfortunately, I cleared the arp table the first time without taking note of its contents, so hopefully this one will be similar to it before the first time I cleared it.

No alerts from the router, but keep in mind, the firmware on that thing isn't on par with something you'd find on a mikrotik, cisco, vyatta, whatever. It's mostly just standard fare for a consumer level router, nothing special on it like DD-WRT or Tomato, so I have no access to its arp table.

Now, it has only happened once since we last spoke, but I've had a crazy schedule and haven't had enough free time to sit and watch this thing. When it did happen, I pinged out to other devices on my lan and received replies. Same goes for the router, it was also pingable. Of course IP addresses beyond the router on the net resulted in timeouts.

As for other network resources, I attempted to access a network drive that I have running and was able to without any noticeable latency.

I did not have a chance to test whether or not changing my mac address would make a difference, because sometimes when the issue occurs, it recovers in about 2 minutes, other times it's more like a blink, then it comes back. And before you ask, I did make sure to run consistent pings to the router as well as beyond on two other machines and leave them running alongside my MBP, which was also pinging the router and a server on the net. While the MBP's pings to the net dropped off, the PC and Linux boxes continued pinging both destinations without timeouts like the mac was experiencing.

I'm not sure what you mean on my lan but on a different network. I have an idea that you might think I have two separate networks here at home, and that you're asking if I can at least route between those two, if not out to the net. Clarify that one for me, please, if I'm wrong.

I didn't have a chance to change my MAC address. I really hope that's not the ultimate fix, since I'm pretty sure it'll just revert to the actual MAC every time I reboot.

Finally, I have no idea what that smart flag is or does. I checked the man page for ifconfig and it makes no mention. Internet searches also led to dead ends or forum posts from others asking the same question and getting absolutely nothing in response.

sorry, i'm a bit out of time myself...

I have an idea that you might think I have two separate networks here at home, and that you're asking if I can at least route between those two, if not out to the net. Clarify that one for me, please, if I'm wrong.

yes

and i was also hoping that the arp table at the time the incidents occur would reveal something that would explain why you could not route at all if that were the case.

i'm really wondering about a local firewall on the machine

you probably can set the mac address permanently in /etc/rc.conf (that would be the bsd way) or bange it using the crontab "@reboot ifconfig CARD_NAME ether wh:at:ev:er:..." i'm not sure that will change much, but it may if some external device (maybe neighbor's) polls the network from time to time with a duplicate mac or something similar...

The truth is, this issue is bizarre. I don't exactly understand why it's happening and I have no indication as to what might be the cause. I do have a lead, thanks to you, since clearing my arp cache puts me right back online. Just no idea why it's happening, even with that lead.

http://community.spiceworks.com/topic/231000-why-do-my-arp-cache-entries-become-corrupted

i'm also pretty confused, but also confident that overtime, we can manage to actually understand and get this issue resolved. you definitely posted a weird one. this is much more interesting than many rtfm questions around. but it's getting narrowed down somehow.

i'd also understand if you consider it is not worth the time

anyway, i'll keep monitoring the thread as long as you keep it open. may be less reactive in the future because i have less time to spend on this forum lately

let's get the machine's and perhaps the router's arp table why the incident is occuring some time when you'll be less busy

best regards

Whenever it happens and I try to display the arp table with "arp -a", I'm noticing that the first entry for my router appears quick, but then it hangs for a good 10-15 seconds before finishing with the rest...

? (192.168.1.1) at 94:cc:b9:28:e0:32 on en1 ifscope [ethernet]
(15 second pause)
? (192.168.1.156) at 44:6d:57:4b:d9:a6 on en1 ifscope [ethernet]
? (192.168.1.255) at ff:ff:ff:ff:ff:ff on en1 ifscope [ethernet]

I hate to be a broken record, but have you checked your router logs to see if some other device is logging onto your wireless network when the connection drops to your Mac?

this is probably a side-effect : use something like arp -an in order to disable name resolution and it should display fast

but your gateway seem to be properly visible. it's the arp table of the controller i'm more concerned about

Happened again. Rebooted my Google TV and bam, connectivity restored immediately. I've tried disconnecting other devices for the same effect, but nothing. Only begins working when I power cycle the Google TV in my bedroom. I think I've found the culprit. I still have absolutely NO clue WHY this is happening, but at least I now have something to focus on, and hopefully a resolution for any future issues that others may run across similar to this one. The strangest thing is trying to understand how the Google TV only affects my MacBook Pro. Odd stuff. I'll post more when I figure this out, if I do.

It's not. I'm just wondering why all of a sudden it's creating an issue on my network, and ONLY for my MacBook Pro?

While there wasn't a sure fix for this from the thread, skullnobrains and strung were fantastic help.

if you ever happen to get to the bottom of this one, i'm interested in the answer even if in 10 years.

best regards