DNS A Records Requirement for Collaboration UC Infra

[VCsupport17]

Hello,

We are implementing Collaboration UC infra with CMS, CUCM, IMP, CUC and Expressway. For each server, is it required to have DNS A record in reverse zone/reverse lookup? Or DNS A record in forward zone is enough for Hostname to IP resolution?

Thanks.

[Jaime Valencia]

You need forward and reverse entries, many servers will show alerts/errors if there is no reverse lookup entry.

[Roger Kallberg]

To add to Java’s response, in the reverse zone you’ll have PTR records, not A records and in the forward zone you’ll have A records.