Hi. I am begginner to network world. Currently im learning everything about network until i reach for my question related to pinging a website.
I pinging from my workstation in my office. My ip address is 18.104.22.168.
My question is, I can view all external websites from my PC without any problem. When i "nslookup" to certain website and ping their IP address from my PC it shows request timed out and some shows destination net unreachable. But at the same time if i enter the websites URL, http:// there will be no problem even enter thier IP address in search bar it works.
What really cause this problem arise? The website can open when enter URL or IP address in search bar but cannot when ping the website IP from my PC.
Thanks in advance. Hope experts can clear my doubts.
Quite a lot of website/hostingISPs and organisations, will generally stop ICMP/UDP Ping requests.
This is to try and mitigate against DDoS attacks that will try and flood a link. They will tend to do this as far away from their links as possible. If for example you have a 2mb link, if you blocked this type of traffic at your site, it will be too late as the link will become saturated. If you could get the ISP to block this traffic before it hits your link then it shouldn't affect your bandwidth (providing the isp has adequate bandwidth to cope with it on their backbone).
The strange thing is when you do traceroutes. Sometimes, the intermediate routers will block traceroutes and you will see that its timed out on that hop, but when it goes to the next hop, you may then get a response (it can sometimes look very strange when you see this)
If you can ping to some devices on the internet through your network then you network/firewall will be ok. It will be the company/ISP that are blocking the other traffic from going through their routers/firewalls.