So, I know that DNS is important in the running of CDN services. DNS allows the routing client traffic to the physically nearest CDN server. Question is, how can I do the same thing without any DNS involved? Note the edge servers are in different geographical locations.

  • 3
    It is called anycast.
    – Ron Maupin
    Apr 18, 2020 at 5:17
  • Your servers in same place or different physical locations?
    – infra
    Apr 18, 2020 at 7:31
  • 1
    This may be an XY problem. Why on earth would you NOT use the DNS for this? You should give more details on what you are trying to do exactly. As is this question is unclear.
    – JFL
    Apr 18, 2020 at 8:14
  • Did any answer help you? If so, you should accept the answer so that the question doesn't keep popping up forever, looking for an answer. Alternatively, you can post and accept your own answer.
    – Ron Maupin
    Dec 17, 2020 at 17:10

2 Answers 2


Using one public IP over multiple locations are called Anycast and it is not related to DNS. DNS just translates FQDN to IP address.

If you assign same IP to different locations, your ISP will route the clients to the closer location. Is your application okay with this?

The most basic use case for anycast routing is hosting DNS servers. When you send DNS query to, you will get response from closest data center.

DNS involvement is not required for anycast. You should agree with your ISP if they allow this, what is their path selection criteria etc. If you have eBGP neighborship with your ISP from two locations, you can easily advertise same subnets. This is the common use case for geo-redundancy.


Using one public ip address for multiple private ip address sound like natting . Where as in NAT overload multiple private ip address are natted with single public address

DNS is used to resolve domain names to ipv4 &ipv6 ip address..

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