Well, the machine is not technically a server, just a normal pc box running linux. I left that machine on in my apartment when I went home for the summer. However, about one month later, I realized that I cannot ssh into my machine any more. I logged into my router, saw my machine is actually on the client list (the link state of the port on which my machine is connected to is actually showing "1000 Full Duplex", which means NIC is sort of up), and assigned an IP (I tried rebooting my router several times, my machine still shows up every time). However, when I tries to ping my machine from my router, my machine never responded.
$ ping 192.168.1.2
PING 192.168.1.2 (192.168.1.2): 56 data bytes
And when I tries to ssh into my machine, it hangs.
$ ssh 192.168.1.2 -vvv
OpenSSH_6.2p2, OSSLShim 0.9.8r 8 Dec 2011
debug1: Reading configuration data /etc/ssh_config
debug1: /etc/ssh_config line 20: Applying options for *
debug1: /etc/ssh_config line 54: Applying options for *
debug2: ssh_connect: needpriv 0
debug1: Connecting to 192.168.1.2 port 22.
Since I have no physical access to my machine, I cannot inspect it personally. Just wondering what's possible reasons for causing this? (it's kind of weird because it seems like the NIC is down, but it shouldn't be able to respond to the router)
arp -an | grep 192.168.1.2
.