> For the complete documentation index, see [llms.txt](https://docs.link11.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.link11.com/product-guides/secure-cdn/faq.md). # FAQ ## **Can Link11 perform full page caching?** Link11’s Secure CDN service will respect the cache control headers set by customers. If the full content for the site or “page” has a cache control header set in a way that allows the content to be served from cache without needing to validate the content with the origin server, then the whole page will be served from cache. *** ## **What size of a file can be delivered by a client over CDN?** The default limit is 100 MB. *** ## **Currently TLS can’t be changed in CDN, but if TLS is limited in WebDDoS does the minimum TLS option still apply?** No, CDN and WebDDoS are two different services. In WebDDoS, one instance = one TLS (per customer). However, in CDN, nginx is being shared by all the customers. The TLS version needs to be available before any information can be obtained from the HTTP request. Thus, it is impossible to configure this on a host basis. *** ## **What is the Cache Size for CDN?** The CDN has a limit of 500GB total per customer. Most individual nodes have smaller capacities (such as 250 GB) due to hardware limitations. If a cache becomes full, this does not create an error condition. The system will merely delete older content as needed, to make room for new cached content. *** ## **For how long does a CDN cache a HTTP error?** Either one minute or five minutes. This is configurable; the time can be configured for all HTTP errors. If the origin sets a higher/lower cache control header, the CDN takes it. *** ## **Is the CDN in front of WebDDoS?** Yes! WebDDoS is located in Frankfurt, London, and Singapore. It does not have global geo-distribution, so we fixed that by using the CDN Platform in front of the Web Platform. Another deployment scenario would be having a subdomain (Ex: [cdn.link11.com](http://cdn.link11.com/)) where all static information is served, while all the dynamic content is served by [link.com](http://link.com/). *** ## **Do we support client-to-proxy custom ports in the CDN ?** No, we only support ports 80 and 443. *** ## **Why doesn’t Geo Blocking work with WebDDoS Protection?** The CDN always stands in front of the WebDDoS proxies. Geo Blocking rules set in WebDDoS are therefore not applicable to the CDN, since our CDNs are whitelisted for our proxies (redirecting through it circumvents Geo Blocking). Also, deactivating HTTP2 should be done (because it doubles the traffic load for the proxies). *** ## **How can I test which TLS Ciphers are supported by the Link11 System?** Please use this Test Service: [SSL Server Test (Powered by Qualys SSL Labs)](https://www.ssllabs.com/ssltest/index.html) ## **Are these TLS 1.2 Ciphers supported?** `TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256`\ `TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384` Yes these ciphers are supported.