bhermer
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Setting up a redundant web server
Hi,
I run a web hosting business, a small one! I currently have two websevers running, both with different ISP's they are NS1 and NS2, both running Win 2003 standard editinon
NS1 is a primary DNS server, and IIS server, and NS2 is a secondary DNS recieving DNS from the primary using zone transfers
What I am looking for is a solution that will enable me to put some redundancy into the system. I need another web server to pick up traffic if one of the servers goes down (maybe another two, I dont know.)
I am happy to hire another server to provide this, but how would I go about setting it up?
I had thought to hire a server to simply handle DNS and if the IIS server went down, is it possible for the DNS server to know this and direct traffice to the second IIS server?
Any help or advice would be appreciated
I run a web hosting business, a small one! I currently have two websevers running, both with different ISP's they are NS1 and NS2, both running Win 2003 standard editinon
NS1 is a primary DNS server, and IIS server, and NS2 is a secondary DNS recieving DNS from the primary using zone transfers
What I am looking for is a solution that will enable me to put some redundancy into the system. I need another web server to pick up traffic if one of the servers goes down (maybe another two, I dont know.)
I am happy to hire another server to provide this, but how would I go about setting it up?
I had thought to hire a server to simply handle DNS and if the IIS server went down, is it possible for the DNS server to know this and direct traffice to the second IIS server?
Any help or advice would be appreciated
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I agree, but the price seems prohibitive. I may misundertsand though, would I need to have all my domains on the fall over system, or just my name server domain name?
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HI,
Currently I host 300 domains (hope to have more), I have ServerA which is the DNS server and the IIS server for all domains that dont use scripting. ServerB is the mail server and IIS for a small number of ASP2 application websites, is it also NS2 (using zone fowarding from ServerA)
99% of domain names are bought through Enom and controlled by me. In enom I assign each domain 2 name servers, ns1.mydomain.com & ns2.mydomain.com, again mydomain.com is registered at enom and the setting up of the name server IP's is done through Enom.
ns1.wizzwoo.com is registered to ServerA's IP adress and ns2.mydomain.com is assigned to ServerB's IP address
The way I understand it is, a browser queries the domain name through Enom first, say 123.com, gets the name server record's IP address, then sends the request onto the name server with a host header. i.e sending 123.com to ip address 10.0.0.1, trhe name server then serves the website.
What I really need is for this to happen:
ServerA is up and running:
ns1.mydomain.com = 10.0.0.1 (serverA IP address)
ServerA is down and not responding
ns1.mydomain.com = 10.0.0.2 (ServerB IP address)
Is this possible with the DNS solutions advertised above? And as I am using host headers, do i just host my name server domain name with the above?
Currently I host 300 domains (hope to have more), I have ServerA which is the DNS server and the IIS server for all domains that dont use scripting. ServerB is the mail server and IIS for a small number of ASP2 application websites, is it also NS2 (using zone fowarding from ServerA)
99% of domain names are bought through Enom and controlled by me. In enom I assign each domain 2 name servers, ns1.mydomain.com & ns2.mydomain.com, again mydomain.com is registered at enom and the setting up of the name server IP's is done through Enom.
ns1.wizzwoo.com is registered to ServerA's IP adress and ns2.mydomain.com is assigned to ServerB's IP address
The way I understand it is, a browser queries the domain name through Enom first, say 123.com, gets the name server record's IP address, then sends the request onto the name server with a host header. i.e sending 123.com to ip address 10.0.0.1, trhe name server then serves the website.
What I really need is for this to happen:
ServerA is up and running:
ns1.mydomain.com = 10.0.0.1 (serverA IP address)
ServerA is down and not responding
ns1.mydomain.com = 10.0.0.2 (ServerB IP address)
Is this possible with the DNS solutions advertised above? And as I am using host headers, do i just host my name server domain name with the above?
ASKER
PS, I at first though that having two namer servers did this automatically, but it turns out this is purley for load balancing, is that correct?
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feptias, I really appreciate your help in this. I will do some further investiogation and get back to you. Hopefully I understand a little better now. Touble is, I am a NET programmer, not a server admin, only running the hosting side line to I have carte blanche when writing web services etc! The whole DNS thing gets me a little confused!
Thanks
Thanks
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ASKER
spread points around as nothing really answerd my Q but you all helped wit the understanding of the topic, thanks
Hello, sorry to respond to an old question but I have the same problems/issues with nameservers and it seems that you (diepes) know your stuff.
Your last comment is exactly what we're trying to do here. I am a beginner on this subject but we were looking for a solution for if our server (with the nameservers on it) would go down.
The thing I'm trying to find out is if it's possible to change nameservers without any delay. So if our server would crash that the next visitor would immediatly get send to the back-up server without any delay (I think that is the cache/TTL you speal about). Is that possible?
Your last comment is exactly what we're trying to do here. I am a beginner on this subject but we were looking for a solution for if our server (with the nameservers on it) would go down.
The thing I'm trying to find out is if it's possible to change nameservers without any delay. So if our server would crash that the next visitor would immediatly get send to the back-up server without any delay (I think that is the cache/TTL you speal about). Is that possible?
hi bt33,
Not sure if i understand your problem, but here go's.
As domains get delegated com[Rootserver] -> company.com normally at least 2 names servers are required for the domain, this will be your 2 or more DNS servers.
When a host looks for your company, he (or the dns server handling his request) will query the Root servers for the DNS server that server the company.com domain. They will then try the DNS server until they get a answer for the request e.g. www.company.com
Your 2 DNS server should be on different subnets/providers if possible, thus eliminating dns as a single point of failure.
Now TTL setting, for every DNS answer a authoritative server returns, it will specify how long the answer may be cached, this is to relieve the load on the dns system.
Thus the rootserver by return your 2 DNS server IP's for a query for company.com with a TTL of 2days. Not a problem as long as one of the Servers are available.
Your servers will then in return server the IP for www.company.com with a TTL (lets say 2hours) for your webserver ip.
Not sure if i understand your problem, but here go's.
As domains get delegated com[Rootserver] -> company.com normally at least 2 names servers are required for the domain, this will be your 2 or more DNS servers.
When a host looks for your company, he (or the dns server handling his request) will query the Root servers for the DNS server that server the company.com domain. They will then try the DNS server until they get a answer for the request e.g. www.company.com
Your 2 DNS server should be on different subnets/providers if possible, thus eliminating dns as a single point of failure.
Now TTL setting, for every DNS answer a authoritative server returns, it will specify how long the answer may be cached, this is to relieve the load on the dns system.
Thus the rootserver by return your 2 DNS server IP's for a query for company.com with a TTL of 2days. Not a problem as long as one of the Servers are available.
Your servers will then in return server the IP for www.company.com with a TTL (lets say 2hours) for your webserver ip.
ASKER
The servers are rented from a third party, so physical devices are out of the question. I am reasonable confident I could write a tool to monitor the web server, and create changes to the DNS using WMI, so in your opinion, if I rented another server and set it up as my primary DNS server, had all records pointing to server A, then have an application monitoring the IIS process on ServerA, if it went down, changed the Records over to ServerB, restarted the DNS service (maybe?) this would work?
What would happen to clients that were reading cached DNS records from there local ISP?