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My understanding of IPs and other DNS-type server-related issues really falls short (read: exteme noob).

I know a dedicated server would increase speed. What, if any, difference in speed would a dedicated IP make? Am I correct in understanding the Best Practices from Yahoo that I could use the second IP to serve up some content, which would increase the number of parallel downloads for the user? Or are both IPs (purchase from same hosting account) going to point to the same server? Or how does it work?

Are there other optimization things I should be aware of when thinking of purchasing a dedicated IP?

I am talking about the speed of serving the webpages, i.e. the speed of my website. Yes, I know that IP and server are completely different, not even opposites, just different. But this, indeed, is my question!

The Question Reformulated:
Will having a second (dedicated) IP on my website speed up the time that it will load and display for the user? Or does that have nothing at all to do with IP, and is only a server issue? I'm sorry if this is still unclear. This is a real question though, I may just not be wording it well.

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umm i'm going to ASSUME you are talking about web site speed optimization. because IP's and servers are VERY different things. I would suggest you re-word the question with some more details on what you really want to accomplish - in it's current form it will probably be closed as 'not a real question' – Zypher Dec 22 '10 at 15:13
I suspect your understanding of what a server is and what an IP address is and how each works is kind of confused... – Bart Silverstrim Dec 22 '10 at 15:18
You guys are all completely correct! I am confused. See, I don't even know enough to word the question correctly ;) I will try to make it clearer. – JakeParis Dec 22 '10 at 15:19
up vote 5 down vote accepted

So, you are kind of there. Although it only tangentially relates to IP. What you are really looking for is a second domain. What happens is your web browser only opens 2 (IIRC) connections to a domain at a time to pull down content. So what happens is if you have a bunch of static content, images, css, javascript files, etc at most you can pull down 2 at a time. What you can do to increase speed is to host different content on different domains. For example if you website needed to pull down 10 files and each file too 100ms to pull down it would take you 5000 ms to pull down all 10 files with a single domain. If you have a secondary domain each pulling down 5 files it would take about 2500 ms to pull down all the files.

Soooo what you really want to do is have a secondary domain to help spread the load of pulling down files - most websites also help things out by putting static content on the secondary domain and using a lean web server like nginx to just host the stuff that isn't dynamic.

Also Jeff wrote a great blog article when Stack Overflow started using

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So first off: 10 files * 100ms = 500ms is a typo, right? Or is there something ELSE I'm not getting here? And I think I get it: even if I have 2 domains hosted on the same server, the browser will still be allowed to open more then 2 connections? So the rule is "2 connections per domain/subdomain", not "2 connections per ip" ? – JakeParis Dec 22 '10 at 15:43
@JMC yep typo sorry(fixing now). Correct the limit is by domain not by ip – Zypher Dec 22 '10 at 15:45
Thank you, but I think that 10 files * 100ms = 1000ms ;) – JakeParis Dec 22 '10 at 15:48
It would be 1000ms if only one file was transferring at a time, but web browsers will request 2 files at a time from a single domain, so the total time should be about half. Adding additional domains allows for even more simultaneous requests. – pkaeding Dec 22 '10 at 16:45
got it. thanks. – JakeParis Dec 22 '10 at 20:10

The speed with which you serve pages has nothing to do with the IP (unless that IP is under a denial of service attack). The IP is the equivalent of your home address. The address has nothing to do with the speed with which you get your mail or are found in the phone book listings.

Your location affects that. In this case, your server. Your bandwidth. The data path between customer and webserver. Those affect your speed. And your application(s) on the server/how they're designed/optimized. Those affect your speed.

Your dedicated IP is necessary for access. DNS. Things like that.

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I like Bart's analogy here. IP address is like an address, and the server might be a flat at that postal address. Extra IP addresses won't help people get there any quicker. – RobM Dec 22 '10 at 15:46
Thanks @Bart. Your answer is very useful to me, but I'll give the win to Zypher, as he as more pieces of information that will help. But thanks! – JakeParis Dec 22 '10 at 15:47

You need a dedicated IP for SSL (unless your webhost is providing the SSL using a shared certificate), that's the big thing.

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Not necessarily. See:… – Warner Dec 22 '10 at 15:17

Throwing resources at the problem might mask the symptoms of the problem - just like putting more water in a bath will mask the symptoms of the water keeping running out.

But just like its better to check that the bath's plughole is in and check for any leaks, you need to analyse the apps running on the server and figure out why they are slowing down.

  1. It might be that you need a faster server.
  2. It might be that you need several servers.
  3. You might need to check that the apps are running efficiently.
  4. It might just be bandwidth?

It might be a mix of all of the above but you need to figure out the precise faults and address them directly.

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Nothing I can do to increase bandwith, is there? I'm on a shared server. – JakeParis Dec 22 '10 at 15:53
That's something you need to ask the provider about - many sell a standard package that includes certain bandwidth provisions and will sell you an increased package if you ask. – RobM Dec 22 '10 at 15:54

A server can mean two things: A) a computer dedicated to sharing resources, usually using TCP/IP, or B) a process running on a computer that is listening for requests, instead of issuing requests.

I'll explain how the concept of an IP address relates to both A and B above.

A - A server, like any computer, has network interfaces, such as NIC cards. For the NIC cards to talk over the Internet or local machines, they must be assigned an IP address. You need a public IP if you want to reach other machines via the Internet.

Most residental ISPs will lend you one for a while via DHCP, but you aren't guaranteed to have the same address over time. "Dedicated IP" might mean the same as "static IP," where an ISP lends you one from their pool as long as you have an account with them.

If you want other people to connect to you, it's easier if your IP doesn't change at the whim of your ISP. That's why static is better for servers most of the time. The only type of server that needs a static IP is a DNS server, because it cannot be referred to by a DNS name.

B - When you start a process on your machine that is acting as a server, that process must "listen" on a given IP address and port. Depending on what the software is, it might be able to listen on all IP addresses, or maybe just certain ones. All systems running TCP/IP support a virtual NIC called the loopback interface, assigned to IP This interface just spits out whatever you feed it, so you can use it for testing (i.e., tell a server process, such as web server software, to accept connections or listen on, and tell your client, the web browser, to access the service on So you at the very least have to decide if you want your processes listening on or the IP address your NIC card has.

A system can have multiple NICs. The typical situation for this are routers, which take traffic coming in from one NIC and forward it to another NIC, if traffic is destined for IP addresses that lie "behind" that NIC.

I hope this was helpful.

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I know a dedicated server would increase speed

No. Like your own car compared to a taxi - your own car may suck. A dedicated server running outdated hardware will not increase speed to a modern shared host.

What, if any, difference in speed would a dedicated IP make?

Depends what yuo do with it. HTTP? none. Actually it is forbidden by IP assignment regulation to waste IP blocks for individual sites. HTTPS - depends on server, some need a separaet IP per certificate. FTP - needs IP, old protocol.

Am I correct in understanding the Best Practices from Yahoo that I could use the second IP to serve up some content, which would increase the number of parallel downloads for the user?

Interesting enough Yahoo does NOT talk about dedicated IP's. Nowhere. Where did you read that? They talk about CDN, which basically means "separate DOMAIN" (!), not IP. Separate domain CAN mean subdomain.

Or are both IPs (purchase from same hosting account) going to point to the same server?

No idea. Ask your hoster. IF (!) "same hosting account" means "with only one dedicated server" then OBVIOUSLY they will point to the same server. Where else?

Are there other optimization things I should be aware of when thinking of purchasing a dedicated IP?

First is your english. You CAN NOT (!) purchase a dedicated IP. When was the last time you OWNED a phone number? You get them assigned, you may rent them (if you are with one of the locw cost providers where you pay more per IP), but you never purchase them as in you never own them.

Basically get what you need. Point.

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Most of this is so full of wrong i don't even know where to begin. – Zypher Dec 22 '10 at 15:31
@Zypher - good to know, thank you. Even with the -2 votes, I was reading it and taking it as true. And @TomTom, I am a native English speaker, just not native in the Server-Admin tongue. ;) – JakeParis Dec 22 '10 at 15:34
Actually most of it is not wrong - Zypher just obviously does not really know what he talks about. – TomTom Dec 22 '10 at 15:40

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