I can not open a specific website. This is a website hosted by our company, and I know it is up. However, these are my symptoms:
VARIABLES:
host.com - the website I can not open
x.x.x.x - the IP of host.com
192.168.0.121 - the IP of my local machine
192.168.0.1 - the gateway IP that gives access to internet
- If I go to the browser and open
http://host.com, then it gives me an error (Unable to Connect in Firefox; Page not Available in Chrome) - If I run
ping host.com, it returns:
PING host.com (x.x.x.x) 56(84) bytes of data. From 192.168.0.121 icmp_seq=1 Destination Host Unreachable From 192.168.0.121 icmp_seq=2 Destination Host Unreachable From 192.168.0.121 icmp_seq=3 Destination Host Unreachable
Please note that 192.168.0.121 is the IP of my own machine.
- A traceroute will also fail miserably:
$ traceroute host.com traceroute to host.com (x.x.x.x), 30 hops max, 52 byte packets 1 192.168.0.121 (192.168.0.121) 3008.068 ms !H 3007.312 ms !H 3009.967 ms !H
And I have already checked the following:
- The website is available just fine from any other computer in our network
- If I try to ping or traceroute the IP directly, the results are the same
- This IP or website is not listed in my
/etc/hosts - There is no firewall rule interfering. I even flushed all rules and tried again; same results.
What can it be?
EDIT:
Connectivity to this particular IP just came back. I can now connect to this website again. But this has happened before: I can connect, and then I cannot connect. It comes and goes, whereas for other computers in the network and for all other people in the public, this site is online all the time.
EDIT 2:
The problem is back. We just had an internet failure and have reset the router, and on all computers internet works just fine. On my computer, internet itself is also fine. It's just this particular domain name. I expect this to mysteriously work again in half an hour or so, but in the meantime I try to debug this issue. Here come some data as requested:
$ netstat -rn
Kernel IP routing table
Destination Gateway Genmask Flags MSS Window irtt Iface
0.0.0.0 192.168.0.1 0.0.0.0 UG 0 0 0 eth0
192.168.0.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
$ nslookup host.com
Server: 8.8.8.8
Address: 8.8.8.8#53
Non-authoritative answer:
Name: host.com
Address: x.x.x.x (this is the right IP)
$ ip route get x.x.x.x
x.x.x.x dev eth0 src 192.168.0.121
cache ipid 0xc740 rtt 1.71s rttvar 1.025s cwnd 10
$ ip route get 192.168.0.121
local 192.168.0.121 dev lo src 192.168.0.121
cache <local> ipid 0xf209
Best Answer
Is there a chance that your IP is duplicated on the network?
Given that you have done all of this testing the next step would be to use an intermediate hop in between and go to the website from your computer.
Use a free
proxyonline. There are several available. I have seen this issue before and it turned out that the IP was beingblacklistedblackholedby the destination system for a period of time.Fail2banhas the ability to block an IP for a specified amount of time.If you can get there from an internet proxy then use a hop closer. Set a forward on another system inside your network, or SSH to another system and try to hit the site. If you still cannot, then the only variable left is the destination machine or the router in between.
Note: I am not a networking guy. But, possibly a cached arp listing with your IP and a different mac, something else on the router that has your IP is blocking it for some reason?
Edit:
Things to try:
arpcacheChanging your MAC:
ifconfig -a | grep -i hwaddrifconfig eth0 downifconfig eth0 hw ether 00:00:00:00:00:00(replace with a different MAC)ifconfig eth0 up