Aireplay question

SephStorm

Attempting a fake authentication attack on a WEP AP. Getting the error that the source MAC is invalid, i'm not surprised since the MAC i'm getting in VMWare for the device is way too long

Results of ifconfig
wlan0mon: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 unspec 18-D6-C7-0D-68-D5-30-3A-00-00-00-00-00-00-00-00 txqueuelen 1000
I copied and pasted the MAC into the command
aireplay -1 0 -e (BSSID) -a (AP MAC) -h (SOURCE MAC) wlan0mon
I also tried removing the trailing zeros but that didn't work, maybe I removed too many.
Any thoughts?

Is the long MAC expected with a USB injection card? Is this due to VMWare or the device being in monitor mode?
Thanks.