Hi raid-zero,  There is no particular reason for using the first two ports, it was just shown that way probably for ease of use and perhaps consistency with FE and BE port usage (also no specific requirement to start from zero and use higher number ports.)  Users can certainly use all four ports on the WAN COM module if they so desire, but as you point out it's largely unnecessary from a bandwidth perspective.  Two 8Gbps port tends to be more than enough WAN bandwidth.  So use the first two, the last two, or any combination - that's fine.  (Now you may want to manually disable the ports not in use to avoid unnecessary/unwanted port connectivity status warnings.)  Minimum HA requirements are two FC WAN COM ports per director.  Gary
The VPLEX FC WANCOM card is a 4 port card, however in every diagram and explanation I've seen for it, only two of the four ports per director are connected.  Is there a specific reason for this?  I know from a bandwidth perspective it is not likely to need 4 x 8Gb, but I am curious to know if there is a specific recommendation to only use the first two FC ports for this purpose.
VPLEX Metro FC WANCOM port count