Losing internet connection 30 seconds after turning on the Mac

Question

I am being connected to the Wi-Fi, but there's no internet connection, it stops working approx 30 seconds after I turn on my iMac. In Windows via Parallels on the same device, the connection is fine. Every other device is working fine, without any connection issues. Tried connecting to another network, same result. Changing MAC adress didn't help. I have Sierra 10.12.5

This is what i gathered as recommended by @User2707001 (sorry for the mess)

in online mode:

iMac-Mikhail:~ MG$ ifconfig; nslookup www.google.de; traceroute www.google.de
lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> mtu 16384
    options=1203<RXCSUM,TXCSUM,TXSTATUS,SW_TIMESTAMP>
    inet 127.0.0.1 netmask 0xff000000 
    inet6 ::1 prefixlen 128 
    inet6 fe80::1%lo0 prefixlen 64 scopeid 0x1 
    nd6 options=201<PERFORMNUD,DAD>
gif0: flags=8010<POINTOPOINT,MULTICAST> mtu 1280
stf0: flags=0<> mtu 1280
en0: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500
    options=10b<RXCSUM,TXCSUM,VLAN_HWTAGGING,AV>
    ether 38:c9:86:25:68:4e 
    nd6 options=201<PERFORMNUD,DAD>
    media: autoselect (none)
    status: inactive
en1: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500
    ether 28:f0:76:26:bb:92 
    inet6 fe80::1852:a5e9:cedc:44fc%en1 prefixlen 64 secured scopeid 0x5 
    inet 192.168.0.103 netmask 0xffffff00 broadcast 192.168.0.255
    nd6 options=201<PERFORMNUD,DAD>
    media: autoselect
    status: active
en2: flags=963<UP,BROADCAST,SMART,RUNNING,PROMISC,SIMPLEX> mtu 1500
    options=60<TSO4,TSO6>
    ether 1a:00:01:0f:43:00 
    media: autoselect <full-duplex>
    status: inactive
en3: flags=963<UP,BROADCAST,SMART,RUNNING,PROMISC,SIMPLEX> mtu 1500
    options=60<TSO4,TSO6>
    ether 1a:00:01:0f:43:01 
    media: autoselect <full-duplex>
    status: inactive
bridge0: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500
    options=63<RXCSUM,TXCSUM,TSO4,TSO6>
    ether 1a:00:01:0f:43:00 
    Configuration:
        id 0:0:0:0:0:0 priority 0 hellotime 0 fwddelay 0
        maxage 0 holdcnt 0 proto stp maxaddr 100 timeout 1200
        root id 0:0:0:0:0:0 priority 0 ifcost 0 port 0
        ipfilter disabled flags 0x2
    member: en2 flags=3<LEARNING,DISCOVER>
            ifmaxaddr 0 port 6 priority 0 path cost 0
    member: en3 flags=3<LEARNING,DISCOVER>
            ifmaxaddr 0 port 7 priority 0 path cost 0
    nd6 options=201<PERFORMNUD,DAD>
    media: <unknown type>
    status: inactive
p2p0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 2304
    ether 0a:f0:76:26:bb:92 
    media: autoselect
    status: inactive
awdl0: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> mtu 1484
    ether 22:93:88:a6:ad:01 
    inet6 fe80::2093:88ff:fea6:ad01%awdl0 prefixlen 64 scopeid 0xa 
    nd6 options=201<PERFORMNUD,DAD>
    media: autoselect
    status: active
utun0: flags=8051<UP,POINTOPOINT,RUNNING,MULTICAST> mtu 2000
    inet6 fe80::1e08:2280:ffce:c67d%utun0 prefixlen 64 scopeid 0xb 
    nd6 options=201<PERFORMNUD,DAD>
vnic0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
    options=3<RXCSUM,TXCSUM>
    ether 00:1c:42:00:00:08 
    inet 10.211.55.2 netmask 0xffffff00 broadcast 10.211.55.255
    media: autoselect
    status: active
vnic1: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
    options=3<RXCSUM,TXCSUM>
    ether 00:1c:42:00:00:09 
    inet 10.37.129.2 netmask 0xffffff00 broadcast 10.37.129.255
    media: autoselect
    status: active
Server:     192.168.0.1
Address:    192.168.0.1#53

Non-authoritative answer:
Name:   www.google.de
Address: 173.194.44.87
Name:   www.google.de
Address: 173.194.44.95
Name:   www.google.de
Address: 173.194.44.88
Name:   www.google.de
Address: 173.194.44.79

traceroute: Warning: www.google.de has multiple addresses; using 173.194.44.87
traceroute to www.google.de (173.194.44.87), 64 hops max, 52 byte packets
 1  192.168.0.1 (192.168.0.1)  1.249 ms  0.841 ms  0.887 ms
 2  185.135.232.97 (185.135.232.97)  8.106 ms  2.245 ms  2.532 ms
 3  192.168.56.9 (192.168.56.9)  2.100 ms  2.171 ms  2.474 ms
 4  192.168.56.1 (192.168.56.1)  1.301 ms  1.390 ms  7.790 ms
 5  spb-81-211-101-113.sovintel.ru (81.211.101.113)  12.569 ms  3.318 ms  4.262 ms
 6  pe01.8marta.moscow.gldn.net (79.104.227.43)  24.653 ms  20.986 ms  21.924 ms
 7  be101-dpi.tf01.moscow.gldn.net (62.141.106.228)  57.068 ms  59.442 ms  65.607 ms
 8  pe03.kk12.moscow.gldn.net (79.104.235.213)  46.834 ms  23.077 ms  16.787 ms
 9  72.14.213.116 (72.14.213.116)  18.630 ms
    beeline-gw.moscow.google.com (81.211.29.17)  19.430 ms  18.128 ms
10  66.249.94.94 (66.249.94.94)  30.678 ms  16.598 ms  16.054 ms
11  108.170.232.47 (108.170.232.47)  23.193 ms  23.111 ms  19.483 ms
12  173.194.44.87 (173.194.44.87)  19.268 ms  19.977 ms *

offline mode:

iMac-Mikhail:~ MG$ ifconfig; nslookup www.google.de; traceroute www.google.de
lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> mtu 16384
    options=1203<RXCSUM,TXCSUM,TXSTATUS,SW_TIMESTAMP>
    inet 127.0.0.1 netmask 0xff000000 
    inet6 ::1 prefixlen 128 
    inet6 fe80::1%lo0 prefixlen 64 scopeid 0x1 
    nd6 options=201<PERFORMNUD,DAD>
gif0: flags=8010<POINTOPOINT,MULTICAST> mtu 1280
stf0: flags=0<> mtu 1280
en0: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500
    options=10b<RXCSUM,TXCSUM,VLAN_HWTAGGING,AV>
    ether 38:c9:86:25:68:4e 
    nd6 options=201<PERFORMNUD,DAD>
    media: autoselect (none)
    status: inactive
en1: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500
    ether 28:f0:76:26:bb:92 
    inet6 fe80::1852:a5e9:cedc:44fc%en1 prefixlen 64 secured scopeid 0x5 
    inet 192.168.0.103 netmask 0xffffff00 broadcast 192.168.0.255
    nd6 options=201<PERFORMNUD,DAD>
    media: autoselect
    status: active
en2: flags=963<UP,BROADCAST,SMART,RUNNING,PROMISC,SIMPLEX> mtu 1500
    options=60<TSO4,TSO6>
    ether 1a:00:01:0f:43:00 
    media: autoselect <full-duplex>
    status: inactive
en3: flags=963<UP,BROADCAST,SMART,RUNNING,PROMISC,SIMPLEX> mtu 1500
    options=60<TSO4,TSO6>
    ether 1a:00:01:0f:43:01 
    media: autoselect <full-duplex>
    status: inactive
bridge0: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500
    options=63<RXCSUM,TXCSUM,TSO4,TSO6>
    ether 1a:00:01:0f:43:00 
    Configuration:
        id 0:0:0:0:0:0 priority 0 hellotime 0 fwddelay 0
        maxage 0 holdcnt 0 proto stp maxaddr 100 timeout 1200
        root id 0:0:0:0:0:0 priority 0 ifcost 0 port 0
        ipfilter disabled flags 0x2
    member: en2 flags=3<LEARNING,DISCOVER>
            ifmaxaddr 0 port 6 priority 0 path cost 0
    member: en3 flags=3<LEARNING,DISCOVER>
            ifmaxaddr 0 port 7 priority 0 path cost 0
    nd6 options=201<PERFORMNUD,DAD>
    media: <unknown type>
    status: inactive
p2p0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 2304
    ether 0a:f0:76:26:bb:92 
    media: autoselect
    status: inactive
awdl0: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> mtu 1484
    ether 22:93:88:a6:ad:01 
    inet6 fe80::2093:88ff:fea6:ad01%awdl0 prefixlen 64 scopeid 0xa 
    nd6 options=201<PERFORMNUD,DAD>
    media: autoselect
    status: active
utun0: flags=8051<UP,POINTOPOINT,RUNNING,MULTICAST> mtu 2000
    inet6 fe80::1e08:2280:ffce:c67d%utun0 prefixlen 64 scopeid 0xb 
    nd6 options=201<PERFORMNUD,DAD>
vnic0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
    options=3<RXCSUM,TXCSUM>
    ether 00:1c:42:00:00:08 
    inet 10.211.55.2 netmask 0xffffff00 broadcast 10.211.55.255
    media: autoselect
    status: active
vnic1: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
    options=3<RXCSUM,TXCSUM>
    ether 00:1c:42:00:00:09 
    inet 10.37.129.2 netmask 0xffffff00 broadcast 10.37.129.255
    media: autoselect
    status: active
;; connection timed out; no servers could be reached

traceroute: Warning: www.google.de has multiple addresses; using 173.194.32.184
traceroute to www.google.de (173.194.32.184), 64 hops max, 52 byte packets
 1  192.168.0.1 (192.168.0.1)  2.063 ms  0.874 ms  0.869 ms
 2  185.135.232.97 (185.135.232.97)  2.174 ms  1.965 ms  1.890 ms
 3  192.168.56.9 (192.168.56.9)  11.893 ms  14.343 ms  11.902 ms
 4  192.168.56.1 (192.168.56.1)  10.282 ms  8.986 ms  10.728 ms
 5  spb-81-211-101-113.sovintel.ru (81.211.101.113)  12.518 ms  12.469 ms  12.921 ms
 6  pe01.8marta.moscow.gldn.net (79.104.226.43)  29.079 ms  29.413 ms  31.094 ms
 7  be101-dpi.tf01.moscow.gldn.net (62.141.106.228)  62.690 ms  62.176 ms  57.607 ms
 8  pe03.kk12.moscow.gldn.net (79.104.235.213)  22.710 ms
    pe03.kk12.moscow.gldn.net (79.104.235.215)  22.640 ms
    pe26.moscow.gldn.net (79.104.225.57)  24.826 ms
 9  beeline-gw.moscow.google.com (81.211.29.17)  36.809 ms
    72.14.213.116 (72.14.213.116)  52.238 ms  21.297 ms
10  66.249.94.94 (66.249.94.94)  17.980 ms  23.172 ms  24.193 ms
11  72.14.235.231 (72.14.235.231)  23.953 ms  19.507 ms  17.455 ms
12  173.194.32.184 (173.194.32.184)  17.141 ms *  18.435 ms

Please add the output of scutil --dns and cat /etc/resolv.conf to your question. — klanomath, Jun 15 '17 at 13:53

user2707001 · Answer 1 · 2017-06-16T12:16:38.700

You might need to gather more data to make a determination.

The following several commands can help.

Open Applications->Utilities->Terminal and run once when the network is working and again when the connection fails.

ifconfig; nslookup www.google.de; traceroute www.google.de

Okay, so in the above, you can see that nslookup fails in "offline" mode. The traceroute succeeds, though. So you have a DNS problem.

What does that mean? For some reason, your DNS is updated after 30 seconds to a non-reachable DNS server. After that, you still have internet connection, but resolving "names" doesn't work anymore.

So, if you type "http://173.194.32.184" in your browser you will see http://www.google.com, but typing "http://www.google.com" won't work anymore.

You can search the internet for probable causes and dig out a solution to the root cause. If you just want things to work, what should do the job is

Open System Preferences
Open Network
Select Advanced
Click DNS tab
Add some DNS servers - e.g. 8.8.8.8 and 8.8.4.4 (google) or 208.67.222.222 (opendns)

Ok... looks like an interesting problem if it still doesn't work.

As klanomath suggested, please add the output of

dig; scutil --dns; cat /etc/resolv.conf; cat /System/Library/LaunchDaemons/com.apple.mDNSResponder.plist

and

sudo dmesg | tail -n 50

you will need to give your password for the last command to execute.

The problem you have reminds me of DNS not resolving on Mac OS X

As suggested there, when the connection drops, try

sudo launchctl unload -w /System/Library/LaunchDaemons/com.apple.mDNSResponder.plist
sudo launchctl load -w /System/Library/LaunchDaemons/com.apple.mDNSResponder.plist

and/or

sudo launchctl unload -w /System/Library/LaunchDaemons/com.apple.discoveryd.plist
sudo launchctl load -w /System/Library/LaunchDaemons/com.apple.discoveryd.plist

if mDNSResponder is unavailable. Does it work again then?

You may want to try to restore the default firewall settings to see if that fixes the issue:

sudo cp /usr/libexec/ApplicationFirewall/com.apple.alf.plist /Library/Preferences/com.apple.alf.plist

ran it as you suggested and posted results in original question — Mike G, Jun 15 '17 at 12:22
edited answer with suggestions. parallels just doesn't update or uses a hardcoded DNS, that's why it works. — user2707001, Jun 15 '17 at 13:21
That doesn't help, unfortunately. Neither typing 173.194.32.184 in browser, nor adding those servers. — Mike G, Jun 15 '17 at 23:29
Oh that comment actually helps. I've seen that before. Added link to that question above. — user2707001, Jun 16 '17 at 19:38

score 0 · Answer 2 · answered Jun 23 '17 at 08:43

So after trying about everything I could find online or at Mac support, What seemed to have helped is creating another user for my Mac. It still feels weird, as at first everything was working fine via new user, but at some point it had same issues, and logging to the original user helped. I had to do this process a couple times before it was stable. So now I'm just working as the original users and everything seems to be fine.

Losing internet connection 30 seconds after turning on the Mac

2 Answers2