Connection timed out; no servers could be reached error
As soon as I had the same situation and reboot did not solve the problem here is my simple steps which could help to find the problem:
- check internet connection
ping 8.8.8.8
If destination is unreachable check if your gateway 10.0.2.2 is reachable. And fix the problem.
if connection is fine you would see something like :
PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data.
64 bytes from 8.8.8.8: icmp_seq=1 ttl=46 time=4.13 ms
64 bytes from 8.8.8.8: icmp_seq=2 ttl=46 time=4.13 ms
- Check if host/dig send packets properly:
sudo tcpdump -n -i en0 host 8.8.8.8
At the same time from another console in the same machine
dig @8.8.8.8 www.google.com
You will get response similar to:
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth0, link-type EN10MB (Ethernet), capture size 65535 bytes
13:34:00.980550 IP 10.0.2.15.56570 > 8.8.8.8.53: 47059+ A? google.com. (27)
13:34:05.980541 IP 10.0.2.15.56570 > 8.8.8.8.53: 47059+ A? google.com. (27)
This means that the request had pass to the external network but did not come back...
You can check what your firewall doing by analysing output of your firewall rules:
iptables -n -L
The problem might be from any firewall between you and 208.67.222.222 or 208.67.220.220 or 8.8.8.8
in my case provider's firewall coincidently block incoming UDP packets from 53 port.
and thus correction of providers firewall rules fix the problem.
Hope this analysis would be helpful to someone.