3 ms·
> Here’s another example of a low-TTL-CNAME+low-TTL-records situation, featuring a very popular name: > $ drill detectportal.firefox.com @1.1.1.1 Is captive p
by vitus 7y ago
> Here’s another example of a low-TTL-CNAME+low-TTL-records situation, featuring a very popular name:
> $ drill detectportal.firefox.com @1.1.1.1
Is captive portal detection not a valid use case for low TTL? The entire point is to detect DNS hijacking of a known domain, which takes longer when you cache the DNS results...
- zamadatix 7y agoCaptive portal detection involves more than just checking for DNS hijacking. The browser tries to load http://detectportal.firefox.com/success.txt http://detectportal.firefox.com/success.txt and acts based on how that goes. Having a short TTL does not help.
- vitus 7y agoIf your captive portal is implemented by intercepting your DNS queries, then having a short TTL should ensure that the captive portal actually has a query to intercept. But sure, there are other implementation approaches (e.g. injecting HTTP redirects), which I imagine is one reason why Firefox doesn't literally inspect the DNS reply.