From ceeddf79b8464469a5307a1030862c7c4fe289e9 Mon Sep 17 00:00:00 2001 From: Martin Pitt Date: Fri, 24 Jun 2016 07:54:28 +0200 Subject: resolved: add option to disable caching (#3592) In some cases, caching DNS results locally is not desirable, a it makes DNS cache poisoning attacks a tad easier and also allows users on the system to determine whether or not a particular domain got visited by another user. Thus provide a new "Cache" resolved.conf option to disable it. --- man/resolved.conf.xml | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) (limited to 'man') diff --git a/man/resolved.conf.xml b/man/resolved.conf.xml index 920ce9e89b..024ad6a9c1 100644 --- a/man/resolved.conf.xml +++ b/man/resolved.conf.xml @@ -202,6 +202,23 @@ + + Cache= + Takes a boolean argument. If "yes" (the default), + resolving a domain name which already got queried earlier will re-use + the previous result as long as that is still valid, and thus does not + need to do an actual network request. + + However, local caching slightly increases the chance of a + successful DNS poisoning attack, and might also be a privacy problem in + some environments: By measuring the time it takes to resolve a + particular network name, a user can determine whether any other user on + the same machine recently visited that name. If either of these is a + concern, you may disable the local caching. Be aware that this comes at + a performance cost, which is very high with DNSSEC. + + + -- cgit v1.2.3-54-g00ecf