I can not ping microsoft.com but can open it through Firefox. I am using 12.04LTS. I am able to ping all other websites.
In this particular case, microsoft servers blocks/drops ICMP packets and don't reply to them at all. For such cases is better use other tools like nmap to have an accurate result:
nmap -p 80 microsoft.com Starting Nmap 6.40 ( http://nmap.org ) at 2014-03-03 13:08 AST Nmap scan report for microsoft.com (184.108.40.206) Host is up (0.14s latency). Other addresses for microsoft.com (not scanned): 220.127.116.11 rDNS record for 18.104.22.168: 00001001.ch PORT STATE SERVICE 80/tcp open http Nmap done: 1 IP address (1 host up) scanned in 0.65 seconds
As you can see the "host is up" even through it doesn't answer the ICMP echo packet.
Being Unable to ping a domain on the internet does not mean that the domain is down.
Ping is based on ICMP protocol and some domains stop receiving ICMP pings in their firewall to prevent some kind of SYN attacks (hacking technique)
So You should not use ping to see if a website is up or down. Instead, use telnet for websites on port 80
telnet microsoft.com 80
or use host to detect IPs/namserver
Here i will show you how Microsoft.com block ICMP requests .
ICMP means Internet Control Message Protocol , echo request and echo response are the two operation codes of ICMP used to implement ping .
Bad ICMP packets are used for attacks such as :
Ping of death
ICMP flood attack
ICMP nuke attack
So Microsoft protect there Network by blocking
Traceroute_ICMP , so attackers want use it to exploit there system or know information about there network.
The Tracoute using ICMP (-I) option , shows that routers of microsoft block it and you can see asterisks , and blocking these ICMP packets , disable the ability to ping microsoft.com.