About HTTP, HTTP/2 and HTTP/3

HTTP information

HTTP(s) ports are supported on all services. These ports are protected against Layer 7 threats and feature advanced mitigation and user rule capabilities.

HTTP DNS Backend

HTTP(s) ports are unique in that as well as being directed at one or more backend addresses (recommended setup) they may also be directed at a user supplied domain name.

A DNS backend such as ghs.google.com may be supplied and we will direct requests at the resolved result of this domain. This feature allows the IP address to be determined based on a DNS query performed during the process of the request for load balancing, geo balancing or ease of integration with third party software.

Limitations:* Keepalive is ignored, a new connection is created for each client request. It is not possible to keep connections open as the IP the DNS responds to can change at any time. * DNS requests can add to the latency of page loads, we cache the DNS result internally for a reasonable time however it is important to ensure the Domain Name Server responds reasonably quick and where possible employs a reasonable size cache TTL. * Only the first returned "A" record is utilized, there is no load balancing if multiple records are returned.

HTTP/2 Information

All HTTPS ports include HTTP/2 support which is enabled by default (but can be disabled in the SSL options).

HTTP/2 (originally named HTTP/2.0) is the second major version of the HTTP network protocol used by the World Wide Web.

The HTTP2 protocol is enabled by default on all HTTPS ports at X4B. This protocol is backwards compatible where not supported and offers no functional difference in respect to the operation of a website or service. Your backend web server does not require support for HTTP2. Additionally no changes to a web application should be required, in the same way that you can usually ignore whether your website or application is being accessed over HTTPS or HTTP. Only the web browser and web server need to know. However, if you’re ever using software such Telnet or WireShark to debug your site, you may want to understand HTTP2.

HTTP2 is heavily based off the SPDY protocol.

HTTP/3 Information

HTTP/3 is a (currently) draft HTTP protocol running on top of the IETF (formerly Google) QUIC UDP protocol. At this time we do not offer Layer 7 protection over HTTP/3 however HTTP/3 traffic is protected at Layer 4 and can be forwarded with a UDP type port.