ZyXEL Communications SBG3300-N series User Manual page 234

Chapter 21 L2TP VPN
b. Incorrect server address configured on the client device.
Action: From the Device's GUI, click VPN > IPSec VPN > Setup.
(1) If the Local Gateway Address for Default_L2TPVPN is set to "Any":
From the Device's GUI, click Status. The client device should be configured with one of the
WAN interface IP addresses.
(2) If the Local Gateway Address for Default_L2TPVPN is an IP address:
Use that IP address for the client device to connect.
c. The WAN interface which the Device's L2TP VPN is using is not connected.
Action: From the Device's GUI, click Status. Check if the WAN interface used by L2TP VPN is
connected.
d. The client device has an incorrect IPSec pre-shared key configured.
Action: From the Device's GUI, click VPN > IPSec VPN > Edit Default_L2TPVPN. The client
device should use the same pre-shared key.
e. The L2TP VPN is not fully enabled.
Action: From the Device's GUI,
(1) Click VPN > IPSec > Edit Default_L2TPVPN. Select the Enable checkbox and click Apply.
(2) Click VPN > L2TP VPN > Setup. Select the Enable checkbox and click Apply.
f. L2TP or IPSec is not configured correctly on the client device.
Action: Check the L2TP VPN configuration on the client device.
g. The client entered an incorrect username or password.
Action: From the Device's GUI, click Maintenance > User Account. The client should use one of
the accounts to make the connection.
h. The Device exceeds the maximum number of concurrent L2TP VPN connections.
Action: There are too many clients connected. Wait a while and then retry.
A windows L2TP client fails to connect to the Device with an "invalid certificate" message.
2
Tip: Windows sometimes may show this error even if the client device has been configured with a
correct pre-shared key for authentication. This usually happens at the first connection attempt after
a new connection profile is created. Reconfigure the pre-shared key on the client Windows device
and retry the connection.
An L2TP client device cannot reconnect after it is disconnected.
3
Tip: If a client reconnects right after it is disconnected, the reconnection may fail. Wait 60 seconds
before reconnecting.
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SBG3300-N Series User's Guide