DNS server on Linux ( Sizing and software)

[rssb]

Hello,
I have a requirement to stand up an internal DNS server within my company , which will resolve the internal names and forward any external queries. The number of internal nodes are around 25,000 but I dont expect all of them to use this server for thier queries.

But in case if all the 25,000 devices were to query this , how much hardware would I need in terms of CPU , RAM etc.. we will try to implement DNS SEC down the line. Since I am newly tasked with this, I don't have a current estimate as to what our query rate is now. Currently the servers are Windows 2003 Dell boxes ( 1850's )

Wondering which one is better among RHEL 5 or Solaris / Open solaris is better.

Any pointers, links or ideas are greatly appreciated.

Thank you

[tylerwylie]

CentOS or Red Hat would be fine, or Debian. BIND can have a steep learning curve if you don't know that much about DNS, but this should be fine.

*EDIT*
Also, for 25000 devices you'd probably need a decent box, just not some PoS from the closet. Bandwidth is sort of important too.

[rssb]

Thank you for your reply. When you say a decent size box, would Gig interface a dual core cpu and 8GB of ram do the work.

I found this thread / comment wondering if the comments made by the last author are true with respect to the CPU and RAM size.

http://www.unix.com/gentoo/36991-proper ... t-dns.html

Thanks again.

[tylerwylie]

Thank you for your reply. When you say a decent size box, would Gig interface a dual core cpu and 8GB of ram do the work.

I found this thread / comment wondering if the comments made by the last author are true with respect to the CPU and RAM size.

http://www.unix.com/gentoo/36991-proper ... t-dns.html

Thanks again.

Let me provide you the specs with one of our DNS servers at work that handles similar requests, I'll post that later today.

[dk]

Before buying anything try and find out what the memory, network, and CPU utilization are at right now under the current conditions. You want to know what the Dell 1850's are running at and if they are heavily taxed under the current load.

My recommendation would be to use at least 2 DNS servers (failover) running Debian and BIND 9. I'd go with a dual core setup with 2GB to 4GB of RAM or so. You don't need a tremendous amount of RAM but it's dirt cheap. Like tylerwylie said, bandwidth is important but once you see your bandwidth stats on your current DNS servers it should be easy to decide on what to do in this area.

[rssb]

Thank you Dk, tyler . Can you suggest any tools to measure the current usage. They are windows boxes. Tyler can you please or give your rough specs which you said you might be able to find.

[dk]

You could ask the network admins to give you the historical data on the network port the server is configured on. You could also use PerfMon to get the current network statistics. I'm sure there are other tools as well.