On a dedicated server with multiple IP addresses, how can one address group be slow/time out and all other IP addresses OK?

[RobertFisher]

We utilize a dedicated server to host roughly 60 sites on. The server is with a company that utilizes a lady who drives race cars.... About 4 months ago we realized we had a group of sites down thanks to monitoring alerts and checked it out. All were on the same IP address and the sites on the other IP address were still up and functioning well. When we contacted the support at first we were stonewalled, but eventually they said there was a problem and it was resolved within about 2 hours. Up until recently we had no problems.

As a part of our ongoing SEO we check page load speed for our clients. A few days ago a client who has their site hosted by the same company was running very slow (about 8 seconds to load without cache). We ran every check we could and could not find a reason on our end. The client called the host and were told they needed to be on some other type of server (with the host) at a fee increase of roughly $10 per month.

Yesterday, we noticed one group of sites on our server was down and, again, it was one IP address with about 8 sites on it. On chat with support, they kept saying it was our ISP. (We speed tested on multiple computers and were 22MB down and 9MB up +/-2MB). We ran a trace on the IP address and it went through without a problem on three occassions over about ten minutes. After about 30 minutes the sites were back up.

Here's the twist: we had a couple of people in the building who were on other ISP's try and the sites came up and loaded on their machines. Does anyone have any idea as to what the issue is?

[RobertFisher]

Agreed and thanks, unfortunately, the host provider is anything but a one man op. Its huge. Moving to a tier four farm in Nov/Dec. Major company, in house phone, email, chat support. Etc.

As to Sha......I don't care if her answer came from martians, it was one of the best I have seen. (Note to moz staff......Hint, Hint)  

[ShaMenz]

Nah...the cool stuff is courtesy of my Boss whose brain can be kinda scary at times - I'm just soaking up the awesomeness he spreads around

We have this little reciprocal thing that is improving us both (although I don't think he's ever going to hunger for SEO the way I do! But then, that would make him kinda nuts! hehe)

(since you said "non-server side guy" I'm thinking that I probably should have mentioned that you can basically think of each IP being related to a card similar to a network card in your computer)

That whole owning and renting story is pretty common in that world, but is only a problem if you don't strike someone who knows what they are talking about.

We run our own client servers and I have to admit that I shudder when a client comes to us with an existing account from a couple of specific companies. 8(

No probs, always welcome.

[RyanKent]

@Sha, wow! What an exceptionally thorough and all-around awesome reply!

@Robert, you may have come to this conclusion on your own but perhaps it's time to consider a new host. You mentioned "they do not have the servers they just sell the service". I would definitely recommend purchasing service directly from a host and not from a middleman. A true host will often have their own data center and 100+ employees while middleman can sometimes be a 1-man or otherwise small shop. Their knowledge and support can be quite sketchy.

[RobertFisher]

Ok, Now I am annoyed..... Journalist, web dev, writer, good grammar and spelling, and now this....Server Side Pro...... You are good.

This really does seem to make sense to a non server side type guy. I will follow up before we change to another farm. Just found out recently they do not have the servers they just sell the service. Thanks again Sha

[ShaMenz]

Hi Robert,

I think I've picked up on all of the questions here (there's a lot going on!) and have borrowed some awesomeness from my Tech Wizard (Boss) to fill in the exciting bits, so here goes:

I'll start with the easy one first... well actually, none of them are that hard

As a part of our ongoing SEO we check page load speed for our clients. A few days ago a client who has their site hosted by the same company was running very slow (about 8 seconds to load without cache). We ran every check we could and could not find a reason on our end. The client called the host and were told they needed to be on some other type of server (with the host) at a fee increase of roughly $10 per month.

OK, basically the answer to this one would be that your client's site was being throttled back by the host because it was using more bandwidth than was allowed under their existing plan. By moving them to the next plan (the extra $10 per month) the problem is resolved and the site speed returns to normal. Throttling it back gets the client to call... 8(

OK, 1 down and 2 to go...

About 4 months ago we realized we had a group of sites down thanks to monitoring alerts and checked it out. All were on the same IP address and the sites on the other IP address were still up and functioning well. When we contacted the support at first we were stonewalled, but eventually they said there was a problem and it was resolved within about 2 hours. Up until recently we had no problems.

and also

Yesterday, we noticed one group of sites on our server was down and, again, it was one IP address with about 8 sites on it.

OK, you know already that there can be up to 8 IPs on a box and at times something in the network will go bad. There are some variables here as to what is wrong. If you are on a Class C Network and one IP goes down then it means that the Switch or Router has gone bad (whether it is a Switch or a Router is determined by how the host has their hardware set up). If you are on a Class D Network and one IP goes down, then the problem is one of 3 things, the Card, the port, or the cable connecting the two, related to that IP.

The trick is that the person on the phone needs to realise what they are dealing with and escalate it to get the hardware issue resolved (A recent interaction with that particular host for one of our clients indicated to me that the realization part might be a little hit and miss, so good to have an understanding of what might be happening if it happens again)

Phew! Nearly there, last of all...

**On chat with support, they kept saying it was our ISP. (We speed tested on multiple computers and were 22MB down and 9MB up +/-2MB). We ran a trace on the IP address and it went through without a problem on three occassions over about ten minutes. After about 30 minutes the sites were back up. **

Here's the twist: we had a couple of people in the building who were on other ISP's try and the sites came up and loaded on their machines. Does anyone have any idea as to what the issue is?

OK this one is all about DNS caching. That particular host (the one that likes lady racing drivers) has a fail-over system in place. This means that if an IP goes down, the domains on that IP will automatically fail-over to another box.

So, if you have looked at those domains on your machine, it will be cached. When you go back to check the site you are still looking at the cached version. The other people in the building are coming to the domain fresh and through a different ISP, so they see those domains because they are back up on the new box. 

When the host reps were telling you that it was your ISP, what they really meant was that it had failed-over to a new box and you were still seeing the cached DNS location.

OK, think I covered it all so....that's all Folks!

Have a great holiday weekend!

Sha