EDNS Client Subnet ECS in CDN solution Speaker

EDNS Client Subnet (ECS) in CDN solution Speaker: Pham Tran Kim Chi 2

Agenda - What is EDNS Client Subnet (ECS) - How is EDNS Client Subnet (ECS) - EDNS Client Subnet in Vinadata CDN - Lesson learned 3

Recursive DNS Request

Recursive Geo IP DNS Request

EDNS Client Subnet (ECS)

EDNS Client Subnet (ECS) • RFC 7871 - https: //tools. ietf. org/html/rfc 7871 • Extension Mechanismsfor DNS (EDNS 0) option that is in active use to carry information about the network that originated a DNS query and the network for which the subsequent responsecan be cached. Include client subnet

EDNS Client Subnet (ECS)

Use of DNS servers in Việt Nam • ISP DNS server • Google. DNS server • Open DNS server • Others

How CDN works • GEO IP • Anycast: the content is served from the location the request is received. • DNS based: CDN decides where to best served content from based on DNS resolver/ client subnet. • Multiple criteria • Latency • Packet loss • Throughput • CPU load on server • ……. • This is called mapping • The better the mapping, the better the CDN.

CDN with Anycast

CDN with EDNS Client Subnet

EDNS Client Subnet in Vinadata CDN • Client requestswww. vng. com. vn from Google. DNS. • Google. DNS asks VNG authoritative DNS with client subnet • VNG DNS lookup client subnet and answers with an optimal server for Google. DNS. • Google. DNS give answer for client. • Client request content from the optimal server

Lesson Learned • Deployment concerns • Customize DNS Software to support EDNS. • Ask to be added in EDNS support list. • Privacy concerns • Network scanning. • Security concerns • DNS request increases. • Cache pollution.

Thanks! Contact us: VINADATA JSC Helios Building, Quang Trung Software City, Dist. 12 Ho Chi Minh City, Vietnam support@vinadata. vn www. vinadata. vn 17