dns_test_eil
install guide: INSTALL.md
discuss solution: solution.md
Background
Draft (area-code : country subdivision code)
- latest draft: draft.txt
- Status: https://datatracker.ietf.org/doc/draft-pan-dnsop-edns-isp-location/
Slide TOC
GeoIP-enabled Authoritative Server
EIL: P-model, EIL: L-model, EIL: I-model
Support ECS and EIL at the same time
Path Calculation and Tailored DNS Response
EIL is sufficient for GeoIP-enabled Authoritative Nameserver
Data Provider
IP transit is expensive.
Avoid cross-ISP visit.
GeoIP-enabled Authoritative Server
GeoIP-enabled AUTH return tailor response based on the geolocation of Resolver’s IP.
Is the resolver's IP address close to the client's IP address?
Is the IP geolocation database used by AUTH with high quality?
Public DNS
ISP Resolver’s IP is close to client’s IP.
Public DNS Resolver’s IP may not.
RFC7871: ECS
ECS carry client subnet information for AUTH.
Good:
- Better determine end user’s location.
- GeoIP-enabled AUTH map client subnet to user’s geolocation.
Bad:
- Leak client subnet on the resolution to AUTH.
DNS Privacy
The more domains publish their zones on a third-party AUTH,
the more end user privacy information can be gathered by the AUTH according to the ECS queries.
EIL
COUNTRY-CODE: 2 octets
- defined in ISO3166
AREA-CODE: 6 octets
- ISO 3166-2’s country subdivision code
ISP: 4 octets
-
using shortcut names
-
unique in COUNTRY
<CN, 35, TEL> indicates <China, Fujian, China Telecom>
EIL: P-model
P-model is close to ECS.
EIL: L-model
L-model has the most precisely geolocation.
EIL: I-model
I-model will benefit if the AUTH could not find the approximate geolocation of ISP recursive resolver.
EIL models trade off
P-model is the most recommended.
L-model requires firmware upgrade EIL support on the first-hop router.
Support ECS and EIL at the same time
GeoIP-enabled AUTH can directly support EIL.
Recursive Resolver can choose to:
- send EIL query, if AUTH support EIL
- send ECS query, if AUTH support ECS
- send EIL query to replace ECS query for user privacy concern, if AUTH both support ECS and EIL
Path Calculation and Tailored DNS Response
Data Providers make path calculations to optimize content delivery on the Internet based on the network topology, considering many factors such as IP, RIPs, FIBs, AS Path hops, system load, content availability, path latency, etc.
Note that, Data Providers have the full details of the clients, they can make any complex path calculations without ECS and EIL.
EIL is sufficient for GeoIP-enabled Authoritative Nameserver
If the GeoIP-enabled Authoritative Nameservers support ECS, they can use the client subnet information of ECS instead of resolver's address for geolocation detecting.
Alternative, the GeoIP-enabled Authoritative Nameservers can directly use the < COUNTRY, AREA, ISP > information of EIL without geolocation detecting.
