Fix DNS PTR records; add SOA to various negative DNS responses#28
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jagerman wants to merge 2 commits intosession-foundation:devfrom
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Fix DNS PTR records; add SOA to various negative DNS responses#28jagerman wants to merge 2 commits intosession-foundation:devfrom
jagerman wants to merge 2 commits intosession-foundation:devfrom
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jagerman
commented
Jan 21, 2026
jagerman
commented
- PTR responses were sending back results with the type set to A instead PTR.
- Negative responses (such as a PTR of an unmapped IP, or a ONS that doesn't exist) were not cacheable because of the lack of an SOA record, and in some cases could fall back to an upstream. This fixes it (see commit message for more detail).
Without SOA records, caching DNS servers in front of Session Router (such as you might use on a local network for network-side Session Router connectivity) cannot cache the result, but most of the NXDOMAIN and NODATAs we produce are and should be cachable. Unlike positive records, which have their own TTL, negative results requiring hacking the nack TTL through an SOA record in the authority section from which the MINIMUM value. This commit adds it so that we are doing the right thing. This should also prevent PTR records from falling back to upstream DNS (where the entire private range gets NACKed) by being properly authoritative for the local IPs we serve even when those IPs aren't currently mapped.
tewinget
approved these changes
Jan 21, 2026
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