NetShark Passthru
Riverbed recommends that you do not use NetShark in passthru mode. Passthru mode is not available on xx70 platforms.
The only reason to use passthru mode is to TAP a SPAN port that another device is already using. For example, an IDS. In passthru mode, you do not have to configure an additional SPAN on the device. With this solution, you are using two ports on the NetShark to monitor a single SPAN port.
When you place the NetShark in passthru mode, it acts as a TAP on a live interface. In passthru mode, the NetShark passes traffic between two physical interfaces on the same card.
Note: The passthru mode does not fail-to-wire. If the NetShark loses power or stops operating for whatever reason, the link does not pass traffic.