Is DNS case sensitive?

Hi

One of our applications cannot seem to be able to resolve DNS names unless they are in lower case (which they are entered in the DNS system on).

I was always under the impression that DNS wasn't case sensitive.

Could someone clarify?
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kam_ukAsked:
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mrwalker15Commented:
DNS is not case sensitive.

Can you provide more details?
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kam_ukAuthor Commented:
The DNS record is

ServerA > 192.168.1.1

The application can resolve ServerA to 192.168.1.1

But not SERVERA to 192.168.1.1

Is this an application problem?
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ggoossensCommented:
No. DNS on itself is not case sensitive (RFC 4343) but it depends on your application how it interpretes the received info. As stated into RFC 4343:
"However, the individual octets of which DNS names consist are not limited to valid ASCII character codes.  They are 8-bit bytes, and all values are allowed.  Many applications, however, interpret them as ASCII characters."
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kam_ukAuthor Commented:
Thanks

"However, the individual octets of which DNS names consist are not limited to valid ASCII character codes.  They are 8-bit bytes, and all values are allowed.  Many applications, however, interpret them as ASCII characters."

- What does this exactly mean? :)
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mrwalker15Commented:
What is the FQDN? You may be using WINS/NETBIOS there instead of DNS.

Can you post an NSLOOKUP output?

Thanks.
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ggoossensCommented:
When your application sends an lookup string, it can translate the answer in lower case (although in DNS it was set into uppercase). Here can the wrong conversion happen...
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