Can't assign requested address Fixed, see below Using Mac OS X 10.9 (Mavericks) I noticed that my browser wasn't working. Except some sites like google. Almost nothing works anymore. Except IPV6 connections. There was no problem with that. Also incomming connections on IPV4 like SSH or VNC works. So I tried to connect from the terminal: imac:~ rogier$ telnet www.nu.nl 80 Trying 62.69.174.78... telnet: connect to address 62.69.174.78: Can't assign requested address Trying 62.69.166.18... telnet: connect to address 62.69.166.18: Can't assign requested address Trying 62.69.166.15... telnet: connect to address 62.69.166.15: Can't assign requested address Trying 62.69.174.75... telnet: connect to address 62.69.174.75: Can't assign requested address telnet: Unable to connect to remote host No connection possible. So what went wrong? The netstat -a gives me really a lot of "CLOSED" connections. That could not be a good sign. After some digging on the internet I came to an article on the Apple discussion list about this problem. It turns out that there is (probably) a bug in Mavericks. It gives you a lot of LAST_ACK connections. You can check your connection state with the following command: netstat -n | egrep '^(tcp|udp)' | awk '{print $NF}' | psort If you do the same for IPV6, you get a whole different situation: netstat -l It turns out that after 20 to 25 days, something went very very wrong inside your mac. The only thing that will help is rebooting the whole system. Looking at my own system, I rebooted 24 day's ago. imac:~ rogier$ last reboot reboot ~ Sun Jan 12 11:15 reboot ~ Thu Dec 19 10:53 reboot ~ Wed Dec 11 08:31 reboot ~ Sat Dec 7 09:56 reboot ~ Fri Dec 6 07:24 reboot ~ Thu Dec 5 14:31 Anyone a solution? Update: A temporary solution could be: Thanks Erik J. Barzeski sudo ifconfig en0 down sudo route flush sudo ifconfig en0 up More information: https://discussions.apple.com/thread/5551686 Fixed: It looks like it's being fixed in 10.9.4. Looking at the forum the cause of the problem isn't found, but it's solved by upgrading to 10.9.4. https://discussions.apple.com/thread/5551686?start=150&tstart=0