The server => NW51+ SP7 / BM3.7 +SP3

The Client => VPN 3.8.2
Authentication method = Backward compatibility

The client connects successfully, from NWADMIN BM tools I can see the
connection, everything looks OK but I cannot ping the servers, I cannot
ping the tunnel IP.

In the BM console is displays "Inject Key Inbound failed=-1426" (this
messages shows several times as I try to ping an IP address from the

Any ideas?