pveproxy: add note about bindv6only sysctl

Seems certain hosting environments (e.g. OVH) set net.ipv6.bindv6only
to 1, which caused problems for those users after the 6.4 upgrade.

Signed-off-by: Stoiko Ivanov <s.ivanov@proxmox.com>

diff --git a/pveproxy.adoc b/pveproxy.adoc
index 8d024185862b14041ea3f808ed737429d113f26c..665e575f4dc67f97d1c9750d8cd675a6c0a66d8c 100644 (file)
--- a/pveproxy.adoc
+++ b/pveproxy.adoc
@@ -62,6 +62,9 @@ The default policy is `allow`.
 Listening IP
 ------------
 
+By default the `pveproxy` and `spiceproxy` daemons listen on the wildcard
+address and accept connections from both IPv4 and IPv6 clients.
+
 By setting `LISTEN_IP` in `/etc/default/pveproxy` you can control to which IP
 address the `pveproxy` and `spiceproxy` daemons bind. The IP-address needs to
 be configured on the system.
@@ -102,6 +105,12 @@ long-running worker processes, for example a running console or shell from a
 virtual guest. So, please use a maintenance window to bring this change in
 effect.
 
+NOTE: setting the `sysctl` `net.ipv6.bindv6only` to `1` will cause the daemons
+  to only accept connection from IPv6 clients. This non-default setting usually
+  also causes other issues. Either remove the `sysctl` setting, or set the
+  `LISTEN_IP` to `0.0.0.0` (which will only allow IPv4 clients).
+
+
 SSL Cipher Suite
 ----------------