DNS/Deadwood/検索動作/4について、ここに記述してください。
1. Linking names to IPs
In order to avoid needing to indiscriminately store records in the "additional records" section, Deadwood, when getting an incomplete NS referral, will look to see
- if any of the names in the authority records section have a corresponding IP for the name in the additional records section.
If they do, said names are converted and stored in Deadwood's cache as IPs. If not, they are stored as glueless names.
For example, let us suppose we have an answer like this when we ask for www.example.com:
- Authority section: A name server for example.com is ns1.example.com
- Authority section: A name server for example.com is ns2.example.com
- Authority section: A name server for example.com is ns.example.net
- Additional section: ns1.example.com has the IP 10.2.2.1
- Additional section: ns2.example.com has the IP 10.2.2.2
Deadwood converts this answer to look like this:
- This record contains name servers for example.com
- 10.2.2.1 is a glued name server
- 10.2.2.2 is a glued name server
- ns.example.net is a glueless name server
See dwx_make_ns_refer() in DwRecurse.c for more details.
Conclusion