4 ms·

ELI5 description?

by SimeVidas 7y ago

ELI5 description?

alex_anglin 7y ago
Like HTTP cookies, but that users don't have control over since they're managed by network infrastructure.
- SimeVidas 7y ago
  I’m sorry, I really don’t know much about DNS. I still have many questions: Who sets it? How is it transmitted? Who can access it?
bluejekyll 7y ago
The abstract from RFC 7873: —— DNS Cookies are a lightweight DNS transaction security mechanism that provides limited protection to DNS servers and clients against a variety of increasingly common denial-of-service and amplification/forgery or cache poisoning attacks by off-path attackers. DNS Cookies are tolerant of NAT, NAT-PT (Network Address Translation - Protocol Translation), and anycast and can be incrementally deployed. (Since DNS Cookies are only returned to the IP address from which they were originally received, they cannot be used to generally track Internet users.) —— At the end of the day, the data can really be any 8 byte set of data for the client part and up to 32 bytes for the server section. Which you could technically use to store anything you want (or the upstream resolver could). The linked article talks about using it for tracking users, which the abstract ironically says isn’t generally possible.
- pests 7y ago
  Specifically the tracking is done here by randomly choosing IP addresses from a pool and correlating connection attempts to the resolved IP to the original DNS request. To quote the article: "With 2 IP addresses available in the pool, a 32-bit identifier requires 32 correlated connections. With 256 IP addresses, a 32-bit identifier requires only 4 correlated connections." IPv6 brings it down to just one.
- DanielDent 7y ago
  I published dnscookie.com in late 2015. I google "dns cookies" and a few other things terms, was surprised that the terminology appeared unused, and it seemed suitable for the concept I was describing. In May 2016, RFC 7873 was published which also uses the term "DNS cookies". These two things share a name but have different meanings. The naming collision is an unfortunate coincidence.
  - bluejekyll 7y ago
    Oh! Wow! That was a huge assumption on my part. I had assumed it was the afore mentioned RFC. That explains why the site make no mention of EDNS or OPT records. TIL...
deleted 7y ago
[deleted]

ELI5 description?

alex_anglin 7y ago

Like HTTP cookies, but that users don't have control over since they're managed by network infrastructure.

SimeVidas 7y ago
I’m sorry, I really don’t know much about DNS. I still have many questions: Who sets it? How is it transmitted? Who can access it?

bluejekyll 7y ago

The abstract from RFC 7873: —— DNS Cookies are a lightweight DNS transaction security mechanism that provides limited protection to DNS servers and clients against a variety of increasingly common denial-of-service and amplification/forgery or cache poisoning attacks by off-path attackers. DNS Cookies are tolerant of NAT, NAT-PT (Network Address Translation - Protocol Translation), and anycast and can be incrementally deployed. (Since DNS Cookies are only returned to the IP address from which they were originally received, they cannot be used to generally track Internet users.) —— At the end of the day, the data can really be any 8 byte set of data for the client part and up to 32 bytes for the server section. Which you could technically use to store anything you want (or the upstream resolver could). The linked article talks about using it for tracking users, which the abstract ironically says isn’t generally possible.

pests 7y ago
Specifically the tracking is done here by randomly choosing IP addresses from a pool and correlating connection attempts to the resolved IP to the original DNS request. To quote the article: "With 2 IP addresses available in the pool, a 32-bit identifier requires 32 correlated connections. With 256 IP addresses, a 32-bit identifier requires only 4 correlated connections." IPv6 brings it down to just one.
DanielDent 7y ago
I published dnscookie.com in late 2015. I google "dns cookies" and a few other things terms, was surprised that the terminology appeared unused, and it seemed suitable for the concept I was describing. In May 2016, RFC 7873 was published which also uses the term "DNS cookies". These two things share a name but have different meanings. The naming collision is an unfortunate coincidence.
- bluejekyll 7y ago
  Oh! Wow! That was a huge assumption on my part. I had assumed it was the afore mentioned RFC. That explains why the site make no mention of EDNS or OPT records. TIL...

deleted 7y ago

[deleted]