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Setting TTL for DNS Host

I am in the process of setting up a second A record in my DNS for my domain name, my default TTL is set for (7200) for my primary host IP but I’m trying to find a happy medium for the TTL so that it looks at the second IP before the web browser times out. As of now it reads

Primary: www .abc-123.com TTL (7200) IP (192.168.1.23)

Secondary: www .abc-123.com TTL (7200) IP (192.168.2.25)

Any recommendations

Thanks

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giltjr

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ahmad1467

ASKER

I'm looking to have a low TTL to allow me a backup path to access the web site if the main IP address is not available.

giltjr

O.K, as I stated in the 1st e-mail. The only way that really works, is if you remove the "main" IP address from DNS. As long as the IP address of the "main" server is in DNS, the server will respond with that address and the users will try to get it.

In fact there is no "main" and "secondary" addresses to DNS. There is just a list of addresses. The DNS server will hand it out in round robin form. That is, 1st query get address #1, second query gets address #2, third query gets address #1, fourth query gets address #2, and so on.

ahmad1467

ASKER

I’m sorry this is all new to me; I just want to make sure we are talking about the same DNS record.Is this the DNS A record for my domain name? In my setup I have a domain name configure with two IP address from two different providers. On my firewall I have both connections coming in then in my FW rules I have two different Net Trans pointing to the same web server. Would this be the same thing?

Thanks

giltjr

Yes we are talking about A records.

You have a single A record with two IP addresses. When I say "lookup hostname abc-123.com" the 1st time I will get back 192.168.1.23. The next person will get back 192.168.2.25. The next person will get back 192.168.1.23, and it keeps alternating.

If 192.168.1.23 goes down, the DNS server has no clue that it is down and will continue to respond with that address on every other query. So every other person will attempt to connect to the IP address that is down.

Read on round robin dns here:

http://en.wikipedia.org/wiki/Round-robin_DNS