DNS (connection spesific suffixes)

Dracula28

I have a question related to connection spesific suffixes. Say Computer1 has two LAN connections. And these two connections have the following suffixes and IP addresses;

computer1.Lan1.example.com 10.1.1.11
computer1.Lan2.example.com 10.2.2.22

While the primary dns suffix for the computer is;

computer1.example.com

What I'm wondering is, if someone connects to the computer1 with the primary dns suffix, computer1.example.com, which one of the LAN connections will be chosen to connect to the computer? And must computer1 have two A resource records, with both poitning to two different ip addresses?

dynamik

It'll connect to the IP that is in the A record in DNS. You could configure this manually or choose to have the connection register itself in DNS.

A machine will connect to the interface that is on the same subnet as itself if there are multiple A records.

Off the top of my head, I can't remember how it will handle multiple A records on the same subnet.

donald7862003

I believe its Round Robin you can use in DNS to configure two separate host records with same fqdn and two different ip's. what will happen is the DNS server will give the first one and if somebody else request that same fqdn they will get the other. I think

donald7862003

didnt read your question thoroughly I would like to cross out my remark above thats for ip's sharing the same fqdn

dynamik

I couldn't remember if that was the default behavior. Looks like it is; good call.

donald7862003 wrote:

By default, DNS uses round robin to rotate the order of RR data returned in query answers where multiple RRs of the same type exist for a queried DNS domain name. This feature provides a simple method for load balancing client use of Web servers and other frequently queried multihomed computers.

http://technet2.microsoft.com/windowsserver/en/library/e0f49958-f290-49fc-adb4-71ed8deefd621033.mspx?mfr=true

dynamik

donald7862003 wrote:

didnt read your question thoroughly I would like to cross out my remark above thats for ip's sharing the same fqdn

Geez. I didn't either.

Well, now you know what would happen if they were the same

Anyway, I'm not sure if you would automatically get an A record for computer1.example.com. You may have to set it up manually if you choose to use connection specific dns suffixes for both NICs. And you would only need A records for the FQDNs you want to resolve to IPs. You don't have to set up any, but you would need one for each one if you wanted to set them up that way.

jbaello

dynamik wrote:

It'll connect to the IP that is in the A record in DNS. You could configure this manually or choose to have the connection register itself in DNS.

A machine will connect to the interface that is on the same subnet as itself if there are multiple A records.

Off the top of my head, I can't remember how it will handle multiple A records on the same subnet.

Don't they both get an A record the default configuration registers itself to the DNS server, I didn't read the question that well either, but that looks like a multiple host conflict in DNS.

I'll test this tonite...

I would also assume that whichever connection is on the same subnet as the DNS communicates first.

Dracula28

Thanks for the input guys. I guess the A resource record for computer1.example.com is redudant, but I saw a similar example being mentioned in the training kit, so I got curious on which connection it would choose, if you used the A resource record for the primary dns suffix to connect to the computer, and not the connection spesific suffixes.