Infrastructure Network Doubt

[icoctechno]

Hello,

We have some 7 different departments in our Organization and exact details are as follows

For Example

1. 10.66.1.x --- Only for Servers (Gateway 10.66.1.1)

2. 10.66.2.x --- Software (Gateway 10.66.2.1)

3. 10.66.3.x --- Marketing (Gateway 10.66.3.1)

4. 10.66.4.x --- Management (Gateway 10.66.4.1)

5. 10.66.5.x --- Technical (Gateway 10.66.5.1)

We have 3 ISP lines and for some Departments(Marketing and Software) we will give ISP 1 line and other departments like Software,Technical and Servers with ISP2 and ISP3 will be auto failover for ISP1 and ISP2.

Question

1. All the departments should access the Servers (10.66.1.x) and also the internet

2. Auto Failover of internet should happen...

3. Each departments are independent

4. We are going to use some open-source software

Please advice and help me to resolve this query / doubt.

Thanks & Regards
Icoctechno