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phase52010 Author

Level 1

18 points

"NETWORK CHANGE DETECTED" - Broadband dropping out

About 4 to 5 weeks ago I started finding my broadband connection would just 'drop out'.

I'd lose it. No email or internet browsing, nothing.

It might come back on it's own, it might not.

Generally I'd run diagnoistic's, and some time sit would come back immediately, some times I'd have to run it a few times

Sometimes I'd give up and walk away.

Often I get the message "NETWORK CHANGE DETECTED", and the connection would re-establish itself.

It may run for minutes, and I'd be back at square one, or it could run OK for days.

All extremely frustrating.

I've read past posts and see that this problem has come up before, but I cannot find a "do this to fix it" resposnse.

Seeing that it's happened to others, I'm hoping it's something Apple can advise on.

Does anyone know why this happens and how to fix it. I'm really at my wits end.

I've been in contact with my internet provider who give me the usual answers.

Mac-Mini (2.4Ghz Intel Core 2 Duo) running OS 10.6.7

8Gb Ram

Netcomm Modem NB6PLus4W

Broadband ran fine from Late December 2010 until mid may 2011. No idea whats cause this issue.

Thanks all.

Robert

Mac mini, Mac OS X (10.6.7), Netcomm NB6PLus4w Modem

Posted on Jun 13, 2011 6:14 AM

31 replies

Vicleo

Level 1

5 points

Jul 1, 2011 7:35 AM in response to Vivere Somnium

Since I saw this thread I have 5 wireless networks showing only one other on my channel. We are all showing 20% for noise and frequency of 2412. When I do the tpg download test on ethernet it starts every time at 772 KB/sec but on wireless it is up and down like a yo-yo. Also I took my mac to my parents house in the same suburb - he is on voipadsl2 with another provider (internode) he is a gamer and he mentioned they have him on Annex - M and a low...... I forgot what the second word is that the gamers like. Anyway had absolutely no problems with connecting to his router either via ethernet or wirelessly - no change in speed when on wirelessly and no dropouts. Dad has a billions wireless router and is really happy with it. I have not installed MacKeeper but have just had all these problems from the start. Dad searched some blogs for netcomm and found a lot of comments on mac regarding compatability issues with routers.....could this be the problem?

Would any of the airport options/time capsule help with this?

Don't know if it is a co-incidence but I cannot connect to my work webmail via domino access on this computer - apparently my software is too new it would get past various validation certificates and then come up with an error message with safari.

I also have a work computer - lennova connected via 3G dongle and it works perfectly.

Does this help more?

AussieDJ

Level 4

1,445 points

Jul 1, 2011 7:43 AM in response to Vicleo

Find me on whirlpool.

Jul 10, 2011 3:55 AM in response to Vicleo

Completely unhooked Billion wireless modem/router and re-connected - still "Network Change Detected", although in the last 2weeks this seems to be less often now?

Has anyone else found the source of this problem and/or a fix?

phase52010 Author

Level 1

18 points

Jul 10, 2011 4:32 AM in response to Vivere Somnium

Vivere;

This is going to sound really strange; but once you are reconnected go to System Preferences; go to NETWORK and LOCK it to prevent further changes.

And if you aleady had it locked all that time can you report back.

thanks.

robert.

Jul 10, 2011 6:39 PM in response to phase52010

Hi Robert,

Yeah that was actually a tip I posted a while back too, it did seem to reduce NCD but not always. And the padlock seems to open if you enter the Master Password for something else.

Thanks,

phase52010 Author

Level 1

18 points

Jul 10, 2011 8:52 PM in response to Vivere Somnium

Hi Vivere;

Sorry about that, my memories not what it was, and I really should learn to read previous posts first.

On the topic of locking the NETWORK preferences, I have found that it does seem to "work", at least I haven't had any "Network Change Detected" messages since doing. Except for one occassion when I found the Network preferences had unlocked. As you mention the padlock does appear to open if you enter the master password for something else.

Now I have the odd situation of the locking mechanism not locking. The lock is open, I click on it and nothing happens. At least it appearred that way. A message seem to be appearing but so quickly I couldn't read it. I did a screen recording and found one frame with the message "Deauthenticating". The lock still refuses to lock, but only on the Network preferences. On "Accounts" for example, it locks and unlocks without issue. All very odd. Must do a scan of the forums to see if there is an answer.

Robert.

Jul 10, 2011 11:32 PM in response to phase52010

No drama Robert - good to get your feedback on the Padlock / Master Pasword.

Things have become a lot better - I remember a few weeks back it was happening every 5mins.

Still the cause remains a mystery to me?

Jul 30, 2011 12:35 AM in response to Vivere Somnium

Hi group, just thought I'd add an update after I installed Lion OS...

Even more WiFi dropouts and Network Changes Detected - even re-asking me for my network key???

Once I couldn't find my printer on the Wirless network until I went through the WiFi diagnostics. So I am convinced, as suspected, this is not a ISP problem, rather a software WiFi issue.

Still non the clearer which software is the problem, OS / MacKeeper / Firefox browser?

Anyone get a fix, or isolate the problem?

Does anone know how to access the Network Changes log to find out what the Change is?

AussieDJ

Level 4

1,445 points

Jul 30, 2011 1:49 AM in response to Vivere Somnium

Are some of the lights going out on the modem that connects to your ISP, or flashing instead of stayiing solid green when the dropouts occur?

What type of service do you have?

ADSL?

ADSL2?

CABLE?

DIAL UP?

phase52010 Author

Level 1

18 points

Jul 30, 2011 4:52 PM in response to Vivere Somnium

Vivere;

Update: when the problem first occurred I did as my ISP suggested:

- I've swapped out and replaced every piece of cable I could.

- I've reset and rebooted the modem.

- Swapped my connection to a different wall socket.

- Etc, etc.

Wihtout much result.

Since locking my system preferences, (I found if I lock one preference, they all lock, as to why I couldn't lock from the network preferences pane I have no idea), I haven't had the "continual every 5 mins it seems" loose of my internet connection, which resulted in all the above. Was that "THE" solution? I just can't say for sure.

In the meantime I've had my ISP visit my home and check my connection. They also visited my local phone exchange, and I assume, they did something there. No detailed feedback from that to date

It did lead to Telstra visiting the junction box under my unit block and checking from there back to the exchange, after which they declared a 13Mb/s line speed, despite the stand alone tests I did from my lounge room which only got 7mb/s. (Apparantely between the junction box under my building and 3 storeys up I lose 6Mb/s the cable is "so bad").

And that was it from Telstra because they refuse to deal with the cabling inside your house as it's "not their problem". One is left to deal with the issue one's self.

Now the initial failure happened during a period of very heavy and ongoing rain. The problem seemed to fade as the rain did over a few weeks. To date; (and since locking my preferences); I haven't had any dropouts of the "Network Change Detected" variety. I'm at the point of just waiting for the next period of heavy rain to see if it happens again.

It seems to be one of those problems that eithjer "fixed itself"; or was fixed but no-one will tell me what was done; or was due to the weather.

Robert.

PS> I have upgraded to LION; but the 'fix" occurred before that; so I doubt it's made any difference.

Jul 30, 2011 5:58 PM in response to phase52010

Hi Robert / Aussie DJ,

OK I am onto a new fix and 2 days in it seems to be working OK? When I upgraded to Lion I was getting the dropouts every couple of mins again.

There is a thread from a couple of years ago with the same issue...

https://discussions.apple.com/thread/2065872?answerId=9748994022#9748994022

There are a couple of fixes mentioned but the one, and simplest one, I went with was going to Network Preferrences / Location / Edit and delating all the Manual locations that have accumulated, only leaving the Automatic.

I do use my MacBook Pro at various locations so I can't say this will be a long term fix?

AussieDJ

Level 4

1,445 points

Jul 31, 2011 7:06 AM in response to Vivere Somnium

Vivere Somnium wrote:

There are a couple of fixes mentioned but the one, and simplest one, I went with was going to Network Preferrences / Location / Edit and delating all the Manual locations that have accumulated, only leaving the Automatic.

I do use my MacBook Pro at various locations so I can't say this will be a long term fix?

More than likely.

phase52010 Author

Level 1

18 points

Sep 18, 2011 3:08 PM in response to AussieDJ

OK, eventually got TELSTRA to check the line, (which as I'm in a block of units they will only do from the junction box downstairs, after that "it's your problem buddy"), and I was told I had a 13Mb/s connection.

(Crikey do we need to replace this old copper wire setup or what).

I eventually replaced the phone socket which was "old" and this gave me a 10Mb/s connection according to my tests.

Everything at my end is as good as it can be. And the "Network change" issue faded after atime.

I did notice it came back after some HEAVY rain a week or two back, for a day or two and then faded again. This is unlike May when we had days of rain.

It's running 'OK" again, so I'm leaving it at that.

gmarthan

Level 1

0 points

Nov 29, 2011 12:07 PM in response to phase52010

Hi everyone,

It has been some time since anyone was active on this topic, but I was wondering what the others here who claimed to have the same NCD problem have done or are you still facing the same issue?
I have exactly the same issue as described in the first post: my connection randomly fails and when I click on the Alert: No internet connection, click next, select my network and it works again saying Network Change Detected...

I am not sure if it only happens in my home network, since I use my home network 90% of the time and haven't experienced it anywhere else. I'm also not from Australia, but from Estonia. But what catched my eye was that previously mentioned MacKeeper- I'm pretty sure my problems started after installing it, well it's long gone now, didn't find much use to it after all.

I also don't believe its the wireless router since my girlfriends PC works fine. Checked the iStumbler too, nobody on the same frequency. I actually suspected that my MBP's wireless card is failing, but after reading all this...

Nov 29, 2011 1:38 PM in response to gmarthan

Hi,

OK, while I never got to the bootm of the cause, there are a few things you can try.

1) Internet Preferrences > "Locations" drop down box at the top - delete saved locations and set to "Automatic"

2) I also became suspicious that my wireless password had been hacked, so I reset the password key on the router to a WA2 Personal / hidden wireless key.

Things seemed to improve after this. I am not sure if Mac Keeper had a role in it, but I have kept Mac Keeper and all seems fine now.

"NETWORK CHANGE DETECTED" - Broadband dropping out