Thanks to all STP experts, my quick question is: would a PIX 7.0 running in transparent mode break a spanning tree domain? since the PIX in transparent mode itself doesn't participate in STP, in other words: I have a 6509 with 2 3550 switches out to my wan and a transparent PIX in between them, the other question is how do I make sure that my 6509 does not participate in the same STP domain as the 3550's? thanks again.