added_proxy_setting_in_faq

faq/README.md

@@ -26,6 +26,13 @@ able to setup correct MTU with its counterpart via Path MTU Discovery. Docker ne
 1442 MTU in [Docker](https://docs.docker.com/v17.09/engine/userguide/networking/default_network/custom-docker0/) or
 [Kubernetes](https://docs.projectcalico.org/v3.5/usage/configuration/mtu).
 
+## Issues with proxy in private networks
+OpenStack instances can either use public or private networks. If you are using a private network and you need to access to the internet for updates etc.,
+you can use muni proxy server *proxy.ics.muni.cz*. This server only supports HTTP protocol, not HTTPS. To configure it you must also consider what applications 
+will be using it, because they can have their own configuration files, where this information must be set. If so, you must find particular setting and set up there
+mentioned proxy server with port 3128. Mostly applications use following setting, which can be done by editing file `/etc/environment` where you need to add a line 
+`http_proxy="http://proxy.ics.muni.cz:3128/"`. And then you must either restart your machine or use command `source /etc/environment`.
+
 ## How many floating IPs does my group project need?
 One floating IP per project should generally suffice. All OpenStack instances are deployed on top of internal OpenStack networks. These internal networks are not by default accessible from outside of OpenStack, but instances on top of same internal network can communicate with each other.