Joe_Budden
asked on
DNS multiple A records/CNAME query
Hello
We are running Windows 2003 AD DNS - domain is company.com
We have a web application that we want to be accessed on http://webapp.company.com
The actual application will be running on two Windows 2003 Servers - server1.company.com and server2.company.com
Does anyone know how I can make "webapp.company.com" point to both servers (for load balancing)?
Do I:
i. Create an A record for 'webapp' have it point to the IP addresses of server1 and server2
ii. Create a CNAME entry of 'webapp' for the A records of server1 and server2?
iii. Something else?
Also - do I need to make the PTR records point back to 'webapp'?
Secondly, I would also like to implement some sort of fault tolerance here. So that if, say, server1 was down, all requests would go to server2.
iv. Am I correct in thinking that the solution I implemented for DNS load balancing above would not help? Even if a server was down, DNS would still return either address for requests?
v. What I need is a load balancer (Cisco etc)?
We are running Windows 2003 AD DNS - domain is company.com
We have a web application that we want to be accessed on http://webapp.company.com
The actual application will be running on two Windows 2003 Servers - server1.company.com and server2.company.com
Does anyone know how I can make "webapp.company.com" point to both servers (for load balancing)?
Do I:
i. Create an A record for 'webapp' have it point to the IP addresses of server1 and server2
ii. Create a CNAME entry of 'webapp' for the A records of server1 and server2?
iii. Something else?
Also - do I need to make the PTR records point back to 'webapp'?
Secondly, I would also like to implement some sort of fault tolerance here. So that if, say, server1 was down, all requests would go to server2.
iv. Am I correct in thinking that the solution I implemented for DNS load balancing above would not help? Even if a server was down, DNS would still return either address for requests?
v. What I need is a load balancer (Cisco etc)?
ASKER CERTIFIED SOLUTION
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
It won't really afaik, you need to configure load balance or cluster failover.
In that case, just configure 2 A records with the same name pointing to the different servers. It only will balance the load on a 50-50 basis.
Be aware also that if your app keeps session of the client, you need to maintain it and that can´t be done with DNS.
Be aware also that if your app keeps session of the client, you need to maintain it and that can´t be done with DNS.
ASKER
Thanks - so for purely round robin, I couldn't do any of these:
i. Create an A record for 'webapp' have it point to the IP addresses of server1 and server2
ii. Create a CNAME entry of 'webapp' for the A records of server1 and server2?
I would need to create two seperate A records, and have each one point to the IP's of server1 and server2?
i. Create an A record for 'webapp' have it point to the IP addresses of server1 and server2
ii. Create a CNAME entry of 'webapp' for the A records of server1 and server2?
I would need to create two seperate A records, and have each one point to the IP's of server1 and server2?
You can´t create an A record pointing on 2 addresses. The only way is to create 2 separate A records with the same name pointing to each server
ASKER
Thanks...
What is wrong with (ii) [the CNAME idea] too? Just so I know the reason I am wrong :)
What is wrong with (ii) [the CNAME idea] too? Just so I know the reason I am wrong :)
You can also do the same i told you with CNAME´s. It´s the same.
Regards!
Ariel
Regards!
Ariel
ASKER
Out of interest, if I only wanted to use DNS round robin, how would this work in terms of the DNS entries (questions i and ii)?