Keeping 2 site networks separated

Is starting a new server w/ the same company enough?

[Christopher C]

Hi,

Please bear with a server newbie's question, but I'm starting up a new network of sites that will overlap content-wise somewhat with a network that I currently run. It is important to me that the new network isn't linked with the old one (there would be a conflict of interest between the two sets of sites).

Can someone help me with the implications of opening a second dedicated server with the same company we're currently with? In what ways would it be more obvious that the two networks are under the same ownership?

Thanks,
Chris

[dbowers]

Two common pieces of evidence that dedicated or colocated servers are associated together:
1. IP addresses are in the same "block" -- that is, contiguous, or nearly contiguous.
2. Same DNS servers listed in whois.

In my experience, the most common problem with having two dedicated servers with the same provider is that both servers may be in the same physical datacenter. That means problems that affect one (e.g. network disconnected, DNS servers down, or DoS attacks) also affect the other. In theory, a single disaster, like a fire or thief at the datacenter, could wipe out both networks.

[Christopher C]

Hi dbowers,

>>1. IP addresses are in the same "block" -- that is, contiguous, or nearly contiguous.
2. Same DNS servers listed in whois.<<

Hmm, it sounds like these problems could be handled easily with the same server then. Namely using separated IP blocks & configuring multiple DNS...

How do datacenters normally work, when they set up new servers do they usually use the same IP blocks that could otherwise have been ordered as a new IP block?

[dbowers]

I don't know how the largest companies do it, but the smaller companies I've dealt with typically have 2 or more large blocks of numbers that they already "own". (If your current provider is in the US, search for their name on [arin.net...] , and it will tell you what blocks they currently own. Each region has its own registry.) Sometimes your provider will own their own numbers directly; other times, the numbers are actually owned by one of your provider's upstream connectors, and are semi-permanently "delegated" to them.

A lot of the IPs your provider owns will be unused; that is, there are no servers using those addresses yet. When they need a new IP, they just use one of the unused ones. This prevents them from having to go ask ARIN (or other regional registry) for more numbers every time they bring a new device online.

Often companies will have a rigid strategy for how they like to assign IP numbers. Sometimes it's based on technical reasons, like how much bandwidth you expect to use, or how their existing routers are configured. Sometimes it's based on an arbitrary policy, like assigning the lowest IP number that's available. However, asking for non-contiguous IPs (IPs "on a different subnet") is common, so don't feel shy about asking for it, and asking "why" if they say they can't.

There are potential issues of non-contiguous IPs if you run your own DNS servers, if you need "private" connections between your two servers, or if you ever think you might want to change hosting companies but keep your IP addresses. If any of those three apply, it might be worth it have someone help you out.

Finally, a disclaimer of sorts -- I'm not a SEO, and I don't know what the search-engine implications are to having IPs on different subnets.

[Christopher C]

It played out pretty much as you mentioned. After discussing it a few times with our host they were very adamant that it wasn't possible to choose IPs or even IP ranges. They have a system that does it randomly supposedly but it all worked out in the end as our second server is on a completely separate subnet & IP.

Thanks for the advice :)

Cheers,
Chris