Are there any instruments for DNS rewrite?

I solved a similar use case using BIND. In my scenario, an internal department name changed (and still does change frequently). But I didn't want to maintain old-dept-name and new-dept-name zone files.

So, on my master DNS server, my zone files are defined as:

        zone "old-dept.companyname.net" {
            type master;
            file "GEN/companyname.net";
            allow-query { GEN-CLIENTS; };
            allow-transfer { 
                    key "GEN-KEY";
            };
            // also-notify avoids problems about NS complaints
            also-notify {
                    10.x.x.x key GEN-KEY;
                    10.x.x.x key GEN-KEY;
            };
    };

    zone "new-dept.companyname.net" {
            type master;
            file "GEN/companyname.net";
            allow-query { GEN-CLIENTS; };
            allow-transfer { 
                    key "GEN-KEY";
            };
            also-notify {
                    10.x.x.x key GEN-KEY;
                    10.x.x.x key GEN-KEY;
            };
    };

Notice the same filename is used for both zones. NB: views are heavily used, which is what the GEN* stuff is about.

The key then is on the slave servers to not use the 'file' directive more than once - otherwise you'll run into locking problems during replication. For such zones, the data only resides in RAM. It may not even be necessary to use it at all - it's been a while and I don't recall:

    zone "old-dept.companyname.net" {
            type slave;
            masters port 53 { 10.x.x.x key GEN-KEY; };
            file "GEN/companyname.net";
            allow-query { any; };
            notify no; 
    };

    zone "new-dept.companyname.net" {
            type slave;
            masters port 53 { 10.x.x.x key GEN-KEY; };
            // Notice there's no 'file' listed here - this prevents locking problems during replication
            allow-query { any; };
            notify no; 
    };

It's not a perfect solution, but I can have nearly unlimited "mirrors" of the same zone. The RAM-based zones are not a concern since they reload from the master at a slave server restart/reload or when a zone is updated.

Some drawbacks:

• You may (depending on how it's configured) get some sketchy warnings about NS records being out of zone.
• I'm using only static records - I have not tested using dynamic updates.
• You have to make a decision about reverse lookups. Do you want PTR records to point to old-dept? new-dept? the short name? all? Any option is easily possible, but it IS a consideration.

Good luck!