Q: Thunderbolt to Gigabit Ethernet Adapter does not work any longer

Hi,

I have a MBP 15" Mid 2014 with OSX 10.10.4 and use a Thunderbolt to Gigabit Ethernet Adapter connected to my router (Fritz!Box 7390 with OS 06.30) on a GBit port.

Since a few days that connection does not work any more.

The adapter reports in System Settings > Network a self assigned IP address (e.g. 169.254.218.73). I did not change anything. No software update, neither on the Mac nor on the router. Today I bought a new network cable (Cat 5e, 1.5m) without any success. It still does not work.

The LAN port at the router is still set to 1 GBit.

I also tried a PRAM reset (I hope I did it correct).

System report of the Thunderbolt to Gigabit Ethernet Adapter:

Thunderbolt Ethernet:

  Typ:    Ethernet

  Hardware:    Ethernet

  BSD-Gerätename:    en4

  IPv4-Adressen:    169.254.218.73

  IPv4:

  AdditionalRoutes:

  DestinationAddress:    169.254.218.73

  SubnetMask:    255.255.255.255

  DestinationAddress:    169.254.0.0

  SubnetMask:    255.255.0.0

  Adressen:    169.254.218.73

  Konfigurationsmethode:    DHCP

  ConfirmedInterfaceName:    en4

  Schnittstellenname:    en4

  Teilnetzmasken:    255.255.0.0

  IPv6:

  Konfigurationsmethode:    Automatisch

  Ethernet:

  MAC-Adresse:    ac:87:a3:34:3f:99

  Medienoptionen:    Voll-Duplex, Fluss-Steuerung

  Medien-Untertyp:    1000baseT

  Proxies:

  Ausnahmeliste:    *.local

  Passiver FTP-Modus:    Ja

  Reihenfolge der Dienste:    1

Any help is very welcome.

Thomas