The network
interface are configured to support a multi-homed RRAS server to provide
L2TP/IPsec VPN to clients, one interface is external which is configured behind
a Cisco ASA firewall. Due to L2TP/IPsec being utilized NAT-T is configured to
forward external traffic to this interface. The internal interface is connected
to the Production subnet.
When the server is
booted, you can ping resources both internal and external without issue, if you
use the ping 8.8.8.8 -t command to send continuous ICMP packets, it
begins to fail with General Failure.
It turned out to be,
and you guest it an issue with Microsoft Routing and Remote Access. The fix was
to disable the Inbound and Outbound Filters, although this may seem to
be a security risk in this instance the RRAS server is behind a Cisco ASA
Firewall therefore the software filters on RRAS are not required.
To disable the
filters expand IPv4 and General, then right click on each of the
interfaces and select Properties.
Click Inbound
Filters...
Do the same for the Outbound
Filters but ensure Transmit all packets except those that meet the
criteria below, again click OK.
Now if you attempt to try the ping the resources both externally and internally you will probably find it now works successfully. Yet another fix that would encourage you to deploy a proper hardware VPN concentrator such as a Cisco ASA, Juniper, NetScaler etc.