Troubleshooting OpenVPN Internal Routing (iroute)¶
When configuring a site-to-site PKI (SSL) OpenVPN setup, an internal route must
be configured for the client subnet on the Client Specific Overrides tab set
for the client certificate’s common name, using either the IPv4/IPv6
Remote Network/s boxes or manually using an
iroute statement in the
advanced settings. Each network listed in the IPv4 Remote Network/s and
IPv4 Remote Network/s boxes will have an
iroute created automatically.
Next, ensure that the common name matches and that the internal route is being learned/added as it should be. Log verbosity in OpenVPN may need increased to see if this is working. On Status > OpenVPN the internal routing for the OpenVPN server may also be viewed while the client is connected.
For each network that needs an
iroute statement, the server definition
must also have the same network(s) listed as IPv4/IPv6 Remote Networks or as
route statements in the advanced options box.
Server1 custom options:
push "route a.a.a.0 255.255.255.0"; route b.b.b.0 255.255.255.0;
Client Specific Overrides for Common Name
IPv4 Remote Network/s set to
iroute b.b.b.0 255.255.255.0;
client1 custom options:
(blank -- no route statements needed)
On the server side, every
iroute needs a corresponding
route entries are for the OS to know that the subnet(s) should be routed to
OpenVPN from at the OS level. The
iroute statements are internal to OpenVPN,
so it knows which network goes to which client based on its certificate.