Backing Up to OS X Server Crashes My Network

Hello Apple Support Communities. I have recently been configuring a home server using Mac OS X Lion server. This server's main task is network backup for the other macs around the house. I have one iMac running 10.7.5, one MacBook Pro running 10.9.5, and one Macbook Pro running 10.10.4. I have the time machine service set up and enabled on the server, and all the macs I am trying to back up "see" the hard drive I have selected to use for the backups. I successfully performed the initial time machine backups on all of the macs via ethernet. Then I transferred both Macbook Pros over to my wireless network. I thought I had everything configured correctly, but the Macbook Pro running 10.10.4 is giving me many problems. Every time it attempts to perform a wireless backup to the server, it crashes my network. No other clients, wired or wireless, can access the internet. All I can do to re-gain web access is to restart my router. This is what really is frustrating me, though. The MacBook Pro running 10.9.5 has not had any trouble completing time machine backups over the wireless connection. The backups always complete successfully via ethernet, but only one of the macs can successfully backup via wireless. Does anybody have any thoughts about why only one MacBook Pro crashes my network during wireless time machine backups?

Thanks in advance,

camtechguy98