I have two HDS 9's that are networked together and I want to add another unit on my console. I noticed that there is only 1 port on back for networking so my questions is how do you network all three together? Spliiter?

Are you wanting to share waypoints with the third unit, or share transducers also. If it's waypoints, then a NMEA with a "T" will connect the new one to the other two. For Eithernet, you will need the NEP-2 expansion port.

I think the 9 has 2 Ethernet ports, doesn't it?

I want to share waypoints and transducer. My 9's are flush mounted so I have never seen the back of them. I have a hds 7 on my pontoon and it only has 1 Ethernet port so I assumed all hds only had 1 port.

No sir, the 7 does indeed have just 1 port; but the 9 & 12 both have 2 enet ports.

As usual the scout is correct. Ethernet from the 7 to either 9 should get you what you want.

Correct -- I didn't read "9", the 9's do have dual eithernet ports so they can be daisy chained

Thanks for the help!!!