IPv6 configuration fails on Ethernet if Wifi disabled

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Level 1

15 points

IPv6 configuration fails on Ethernet if Wifi disabled

My iMac running Mountain Lion is connected to the rest of the network via an Airport Extreme.

Normally i use the ethernet connection for the communication. Tpday i noticed, that using the ethernet connection, the iMac has no IPv6 addresses configured.

If I enable the Wifi interface (to the very same Airport Extreme), the proper network prefixes are assigned to the iMac.

Both interfaces are configured to "Automatic".

sh-3.2# ifconfig en1

en1: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500

ether 04:54:53:12:7c:56

inet6 fe80::654:53ff:fe12:7c56%en1 prefixlen 64 scopeid 0x5

inet 192.168.42.132 netmask 0xffffff00 broadcast 192.168.42.255

inet6 2002:5091:bb73::654:53ff:fe12:7c56 prefixlen 64

inet6 2002:5091:bb73::3d66:4a75:7546:e7a1 prefixlen 64 autoconf temporary

inet6 fd00::dead:beef:654:53ff:fe12:7c56 prefixlen 64 autoconf

inet6 fd00::dead:beef:8564:e81f:5b29:16c9 prefixlen 64 autoconf temporary

media: autoselect

status: active

sh-3.2# ifconfig en0

en0: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500

options=2b<RXCSUM,TXCSUM,VLAN_HWTAGGING,TSO4>

ether 3c:07:54:5c:68:8d

inet6 fe80::3e07:54ff:fe5c:688d%en0 prefixlen 64 scopeid 0x4

inet 192.168.42.141 netmask 0xffffff00 broadcast 192.168.42.255

media: autoselect (1000baseT <full-duplex,flow-control>)

status: active

iMac (27-inch Mid 2011), OS X Mountain Lion (10.8.2)

Posted on Sep 24, 2012 11:27 AM

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Answer 1

wteiken

Level 1

0 points

Feb 13, 2013 10:39 PM in response to xyzzy

It seems that some ethernet adapters (in my case two different USB ethernet adapters) loos IPv6 connectivity when the system goes to sleep, causing the adapters to permanently loose IPv6 connectivity until the next reboot. This seems to be specific to individual adapters (i.e., the connectivity is lost for each adapter if connected while the mac is going to sleep).

As a workaround I added a script that is executed on sleep (using sleepwatcher) that disables IPv6 on the interface. When the system wakes up I re-enable IPv6 and then the adapter seems to properly regain IPv6 connectvity.

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