From 109b3f47def64ecd20c00568b335404c1ff97eda Mon Sep 17 00:00:00 2001 From: rpb-ant Date: Fri, 17 Oct 2025 12:16:29 -0400 Subject: [PATCH] Update multisocket README.md (#7621) * Update multisocket README.md I was a bit confused why `multisocket` wasn't working for me, but I eventually found https://github.com/coredns/coredns/blob/38c020941b4938cf5642acfbf5ba5e52a71d320b/core/dnsserver/register.go#L308: ``` // create one server by default if no NumSockets specified numSockets := 1 if group[0].NumSockets > 0 { numSockets = group[0].NumSockets } ``` I tried to summarize my understanding in the README Signed-off-by: Ryan Brewster * Update plugin/multisocket/README.md Co-authored-by: Ville Vesilehto Signed-off-by: Ryan Brewster --------- Signed-off-by: Ryan Brewster Co-authored-by: Ville Vesilehto --- plugin/multisocket/README.md | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/plugin/multisocket/README.md b/plugin/multisocket/README.md index 6fb020249..885c4459f 100644 --- a/plugin/multisocket/README.md +++ b/plugin/multisocket/README.md @@ -62,6 +62,10 @@ If conducting such tests is difficult, follow these recommendations: ## Limitations +The `multisocket` value used for a given listen address is taken from the first server block that binds to that address +in the Corefile. Subsequent server blocks using the same address will not change it. Different addresses may use +different values. + The SO_REUSEPORT socket option is not available for some operating systems. It is available since Linux Kernel 3.9 and not available for Windows at all.