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There’s DoT (DNS Over TLS), which operates on port 853, uses TCP and provides encryption. But it’s also something network operators can easily block since it ru

by AnonC 6y ago

There’s DoT (DNS Over TLS), which operates on port 853, uses TCP and provides encryption. But it’s also something network operators can easily block since it runs on a specific, separate port. DNS over HTTPS (DoH), on the other hand, rides on HTTPS/port 443, which cannot be blocked in networks without causing major disruptions to the rest of the web traffic. A more detailed comparison is here: https://www.thesslstore.com/blog/dns-over-tls-vs-dns-over-https/ https://www.thesslstore.com/blog/dns-over-tls-vs-dns-over-ht...

dsl 6y ago
You can run DoT on 443 as well. Providers that want to block DoH or DoT are going to block providers based on destination IP or certificate fingerprints, not port numbers.
- middleclick 6y ago
  Providers are hesitant to block IP addresses for a multitude of reasons, one of the simplest ones being that different services can run on a single IP. And running DoT on a non-standard port breaks all sorts of things because it will be ... non-standard.
m3047 6y ago
> DNS over HTTPS (DoH), on the other hand, rides on HTTPS/port 443, which cannot be blocked in networks without causing major disruptions... And your point is what, exactly? TLS allows for traffic redirection and for a time people were using this to circumvent firewalls but the big providers who looked the other way locked it down when their traffic started being blocked.
the8472 6y ago
That kind of reasoning reinforces the existing problem instead of breaking things up by making support for arbitrary ports essential.
corford 6y ago
If there was a coordinated embrace and move to DoT (at least for the "last mile" part between end users and resolvers), network operators wouldn't be able to get away with blocking it (see secure IMAP, secure POP etc. for similar shifts in the past).
- sneak 6y ago
  The internet is decentralized and "coordinated embrace" is not realistic or practical. See also: IPv6. Pretty much the whole of the internet has been jammed into tcp/443 now, and it can't much be helped. Internet engineering needs to cope with the world as it is, not how we wish it were.
  - corford 6y ago
    >The internet is decentralized and "coordinated embrace" is not realistic or practical. I disagree, see the success of: letsencrypt, the wide spread use of 8.8.8.8 and 1.1.1.1; dkim/spf/dmarc; imaps, pop3s, tls ldap. Why should a switch over to DoT be any different? If anything it should be easier. The general need for better security and privacy are much more widely understood and accepted concerns these days.
- tptacek 6y ago
  The opposite is true: most DoT advocacy comes from operators (and suppliers to those operators) who specifically and overtly intend to filter DNS.
  - LogicX 6y ago
    As said DNS operator (founder and CTO of DNSFilter.com) - I concur. We’ve been offering DoT for years, but are about to improve the offering with 0-RTT support. We’re also working on POCs of DoH support, but it’s mostly moot compared to our DoT offerings which cover the whole OS, not just the browser.
    - tptacek 6y ago

by AnonC 6y ago

dsl 6y ago

You can run DoT on 443 as well. Providers that want to block DoH or DoT are going to block providers based on destination IP or certificate fingerprints, not port numbers.

middleclick 6y ago
Providers are hesitant to block IP addresses for a multitude of reasons, one of the simplest ones being that different services can run on a single IP. And running DoT on a non-standard port breaks all sorts of things because it will be ... non-standard.

m3047 6y ago

> DNS over HTTPS (DoH), on the other hand, rides on HTTPS/port 443, which cannot be blocked in networks without causing major disruptions... And your point is what, exactly? TLS allows for traffic redirection and for a time people were using this to circumvent firewalls but the big providers who looked the other way locked it down when their traffic started being blocked.

the8472 6y ago

That kind of reasoning reinforces the existing problem instead of breaking things up by making support for arbitrary ports essential.

corford 6y ago

If there was a coordinated embrace and move to DoT (at least for the "last mile" part between end users and resolvers), network operators wouldn't be able to get away with blocking it (see secure IMAP, secure POP etc. for similar shifts in the past).

sneak 6y ago
The internet is decentralized and "coordinated embrace" is not realistic or practical. See also: IPv6. Pretty much the whole of the internet has been jammed into tcp/443 now, and it can't much be helped. Internet engineering needs to cope with the world as it is, not how we wish it were.
- corford 6y ago
  >The internet is decentralized and "coordinated embrace" is not realistic or practical. I disagree, see the success of: letsencrypt, the wide spread use of 8.8.8.8 and 1.1.1.1; dkim/spf/dmarc; imaps, pop3s, tls ldap. Why should a switch over to DoT be any different? If anything it should be easier. The general need for better security and privacy are much more widely understood and accepted concerns these days.
tptacek 6y ago
The opposite is true: most DoT advocacy comes from operators (and suppliers to those operators) who specifically and overtly intend to filter DNS.
- LogicX 6y ago
  As said DNS operator (founder and CTO of DNSFilter.com) - I concur. We’ve been offering DoT for years, but are about to improve the offering with 0-RTT support. We’re also working on POCs of DoH support, but it’s mostly moot compared to our DoT offerings which cover the whole OS, not just the browser.
  - tptacek 6y ago