Ignorant question on websites and IP addresses

[Angel Eyes]

Question for those who know more than I about websites and IP (i.e., just about everyone):

If I want to get the IP address of, say, www.example.com, how would I go about doing that?  Would the site necessarily have the same IP address all the time?  Thanks.

[Nick1911]

Question for those who know more than I about websites and IP (i.e., just about everyone):

If I want to get the IP address of, say, www.example.com, how would I go about doing that?

Several ways to do that.  Typically, I open a command prompt (Start -> run, "cmd", enter) then type "Ping www.armedpolitesociety.com"  It will reveal the IP that your computer thinks the site is at, and the connectivity status.

Would the site necessarily have the same IP address all the time?  Thanks.

It doesn't have to, but most rarely change.

[BrokenPaw]

Several ways to do that.  Typically, I open a command prompt (Start -> run, "cmd", enter) then type "Ping www.armedpolitesociety.com"  It will reveal the IP that your computer thinks the site is at, and the connectivity status.

This is probably the simplest way of doing it on a windows machine.

It doesn't have to, but most rarely change.

This is not as necessarily true.  Sites that get a lot of traffic (major portal sites like yahoo, for instance) will generally have their web services provided by several servers.  One way to balance load across multiple servers like this is called "round robin DNS", where a domain name server will, when asked for the address of "www.example.com", return the address for www1.example.com the first time, and www2.example.com the next, and so forth.

This is not a particularly good way to do load balancing, but it does exist in the wild, and you cannot rely on a given request for a site's address always being the same.  They'll almost always be within a small block of IP addresses, but there are no guarantees there, either.

-BP

[Nick1911]

This is not as necessarily true.  Sites that get a lot of traffic (major portal sites like yahoo, for instance) will generally have their web services provided by several servers.  One way to balance load across multiple servers like this is called "round robin DNS", where a domain name server will, when asked for the address of "www.example.com", return the address for www1.example.com the first time, and www2.example.com the next, and so forth.

This is not a particularly good way to do load balancing, but it does exist in the wild, and you cannot rely on a given request for a site's address always being the same.  They'll almost always be within a small block of IP addresses, but there are no guarantees there, either.

-BP

That's a valid point I hadn't considered. 

[Angel Eyes]

That's the info I needed.  Thanks.

[mtnbkr]

During some recent name resolution problems at work, I noticed sites like google even have different IPs served up based on the geographic location of the requester.  That made troubleshooting interesting.

Also, another way to get a site's IP is to open the command prompt as Nick suggested and use the nslookup command.  Type "nslookup www.example.com" and it will tell you what the IPs are.

Chris

[GigaBuist]

Type "nslookup www.example.com" and it will tell you what the IPs are.

That's the better way.  You'll see if they've got multiple A records in the zone that way.