Soumik
The 3560 should be adequate to provide intervlan routing for the branch and the head office. Your post does not tell us whether the head office has any outside connectivity and this might have some impact on the network design (especially in terms of where default gateways might point and whether some dynamic routing protocol was needed.
But based on the description in this post I believe that a /24 for the head office and another /24 for the branch office, and intervlan routing should be an adequate design.
As far as unmanaged devices are concerned there is always a tradeoff about using unmanaged switches. They are less expensive which makes them attractive in some respects. The fact that you can not configure VLANs on them is not a disadvantage in situations where the traffic is all in one VLAN, such as you describe for the branch office. They generally do layer 2 forwarding pretty well. But they do not provide any ability to do troubleshooting. I had an experience at a customer site where they had a networking problem. Their network had only 1 managed switch and a number of unmanaged switches (most of them daisy chained together). We could tell that something was generating large volumes of invalid traffic. But we had no way to find where it was coming from except to go port by port on the unmanaged switches disconnecting and reconnecting ports until we found the one where the invalid traffic stopped. Following this episode they decided to replace most of their unmanaged switches with managed switches to provide better troubleshooting capabilities. From their perspective the money that they saved by purchasing unmanaged switches became less attractive when compared to the cost of the outage that they endured and the extended nature of the outage because they did not have good ability to troubleshoot it. How does you management think about issues such as this?
HTH
Rick
HTH
Rick
