OsmoGGSN: more info on non-root operation / tun creation

Add examples for 'ip addr add' and mention correspondence to config file,
add examples for enabling masquerading and IP forwarding,
place the non-root config in its own section and highlight the diffs.

Add tiny hint at systemd-networkd.

Change-Id: I02bd9cfa35c7f2fb338d5d92c2e968fe80574a78
This commit is contained in:
Neels Hofmeyr 2017-11-13 02:46:38 +01:00
parent 65d61c347b
commit 43001cbc7a
1 changed files with 16 additions and 5 deletions

View File

@ -250,7 +250,7 @@ The interface creation + configuration must then happen before osmo-ggsn startin
achieved by means such as
* a custom shell script run as root before starting osmo-ggsn (e.g. as init script)
* systemd .netdev and .network files
* systemd .netdev and .network files, if your system is using systemd-networkd (see `networkctl status`).
==== Manual TUN device creation / configuration
@ -266,8 +266,13 @@ create a tun device, you must call it like this:
Where _username_ and _groupname_ correspond to the User and Group that will have ownership over the
device, i.e. the privileges which you intend to run osmo-ggsn under, and _apn0_ will be the
name of the network device created. After creating the interface, you can configure its addresses
using standard means like `ip addr add` or your distribution-specific utilities/tools.
using standard means like `ip addr add` or your distribution-specific utilities/tools
to match the `ip prefix dynamic` config item, and activate the link, for example:
----
# ip addr add 192.168.7.0/24 dev apn0
# ip link set apn0 up
----
==== systemd based TUN device creation+configuration
@ -303,10 +308,16 @@ IPMasquerade=yes <3>
You may not want this if you have proper end-to-end routing set up, and want to have transparent
inbound IP access to your GPRS-attached devices.
The pair of the configuration files above allows you to create and configure tun device which can be
used by OsmoGGSN as follows.
==== Config Changes
.Example: using externally configured tun device as non-root
With the tun device pre-configured in one of the ways outlined above, the main
changes in your osmo-ggsn.cfg file are:
* remove `ip ifconfig` directive,
* make sure that `no shutdown` is present in the `apn` section as well as
`no shutdown ggsn` in the `ggsn` section.
.Example: using externally configured tun device `apn0` as non-root
----
ggsn ggsn0
gtp state-dir /tmp