Zabbix is linux based very excellent Bandwidth Monitoring, Network Devices, Servers (Linux, Windows,AIX etc..), Services, etc Monitoring tool.
Another Alternate Tool is use "PRTG" Monitoring, we are also using for MAN (Metropolitan Area Network, WAN, Wide Area Network, Lease Line )
I am running Zabbix and monitoring 400+ servers, 70+ Network Devices, Services etc.. Give a Chance to do this.