[jnewland]

Hey folks, Jesse from GitHub Ops here.

First off, if you use a DNS provider that has support for a ALIAS records or something similar, pointing your apex domain to <username>.github.io will ensure your GitHub Pages site is served by our CDN without these redirects.

I wish we could provide better service for folks without a DNS provider that supports ALIAS domains in the face of the constant barrage of DDoS attacks we've seen against the IPs we've advertised for GitHub Pages over the years. We made the decision to keep DDoS mitigation enabled for apex domains after seeing GitHub Pages attacked and going down a handful of times in the same week. It's a bummer that this decision negatively impacts performance, but it does certainly improve the overall availability of the service.

FWIW, we considered pulling support for GitHub Pages on apex domains about a year ago because we knew it'd be slower than subdomains and would require DNS configuration that would be challenging and frustrating for a large number of our users. However, we ended up deciding not to go that route because of the number of existing users on apex domains.

[thisishugo]

I think anyone tech savvy enough to be using Pages should also be savvy enough to understand[0] why the A records can't (realistically) be as fast as the CNAME alternative, and understand if you make it de facto redundant (i.e. available, but not actively encouraged or supported).

I think it's fantastic that you provide apex support for everyone even though it must be exponentially harder to do that just providing CNAMEs, but if you're upfront about the limitations the only people who are going to complain are the type of people you don't want to be listening to anyway.

[0] I mean that in the sense that they'll comprehend the explanation, not that they'll grok it inherently.

[everydaything]

Possibly not a question you can answer but maybe someone else here can—what are the typical patterns for changing the content of the record? Is the content dynamic based on the requesting resolvers address and other factors? If so does the EDNS client subnet opt come in to play at all?

(I work on DNS things and am curious about what exactly a CDNs needs are.)