What is the difference between the server context and a virtualhost section in the proftpd configuration file? In the sense of what can I do with the former I can't do with the latter.
For example I can not put directives like UseIPv6 or MaxInstances into a virtualhost or the global section but putting it in the server context works just fine. What would then be the correct usage of those sections for the setting mentioned below?
I thought the overall process was the following: Whenever a client connects to the server, the server checks whether there is a virtualhost corresponding to the address the client connected to. If not the server context section gets chosen (except the DefaultServer directive is used to prevent this). So I thought the server context section and a virtualhost section are equally "powerful". But that can't be the case as there are directives which work only in one of the sections.
Long version (additional information):
Basically all I want to do is run a proftp server on a local machine at home and make this server reachable from both the internet and my LAN. And it's working. I compiled proftpd from source (reason below), installed and configured it and it seems to work just as it should. I don't need help getting proftpd to run properly.
I couldn't get the server to run just by reading the proftpd documentation though and I had to keep tinkering with the configuration file until everything worked out just fine. So there is still something about the usage of virtualhosts, global and server context section I don't understand properly and that's why I came up with the questions above.
I read about configuring proftpd behind a router and the meaning of virtualhosts, global and server context section:
I followed multiple guides and searched the forum for similar questions. The server is working, I just don't really understand why it is now and why it didn't before.
This is the structure of my current (working) proftpd.conf:
#server context managing the config for access over the internet ServerName "external" Port 21 #can't be used inside a virtualhost section UseIPv6 off ... #need to masquerade ip for external address MasqueradeAddress myurl.com #needed for passive ftp mode PassivePorts 60000 65535
#virtualhost managing the config for lan access <VirtualHost 192.168.178.54> ServerName "internal" Port 21 PassivePorts 60000 65535 </VirtualHost>
I first thought I should just make two virtualhost sections, one for LAN and one for external access and disable the server context section by setting Port 0. But then there are directives I can't use inside the virtualhost sections. So I'm quite unsure whether I'm using the 3 possible sections as I'm supposed to. Do I need to use the server context section to have some kind of default config? This could be done with the DefaultServer directive according to the documentation.
uname -a: Linux HOSTNAME 3.16.0-4-amd64 #1 SMP Debian 3.16.7-ckt11-1 (2015-05-24) x86_64 GNU/Linux
proftpd -v: ProFTPD Version 1.3.5 The proftpd binary package included in the debian repositories does not support TLS 1.2 and I don't want to use FTP with TLS version below that or even SSL. So I compiled it myself.
This is quite a long text. I tried to shorten it, be precise, avoid unnecessary but provide enough information. If there is anything I could improve or if my question rather belongs to unix and linux stackexchange, just let me know. I chose superuser over serverfault to ask this question because it's about a server environment at home.
Thank you for your time and help.