What happens to traffic sent to an ltm standby unit self ip address?

I need to test weather traffic will flow though and ltm unit that is in standby right now. It is version 10.2.4 1500 appliance Ive got a server behind the unit with its gateway point to the standby units self ip. I was wondering if a standby would even react to that traffic or how it would process it? I can't go active on this unit until a downtime several weeks away and was wondering weather testing could be done on the standby unit?

 

There is a snat setup on the ltm for the server that would handle the outgoing traffic.

 

Last time I made the standby active I could not reach outside networks. I could ping the gateway but dns would not work nor would ssh traffic go though. I got in this mess because I was trying to upgrade to 10.2.4 from 9.3.1. The path I took was from 9.3.1 to 10.0.0 to 10.2.4. Any ideas would be appreciated