Switch Question

Depends on the budget and your projection of network growth. My suggestions will be expensive. If D-Link is cheap and if you just want to quick-fix your current problem, then go with D-Link switch.

Here are few points about switches:

1) If you plan to have multiple subnets in the future, go with "managed" "layer 3" switches. Unmanaged means they operate only at layer 2; all ports will be in the same subnet no matter what. Managed L3 switches have VLANs; you can specifies which ports belong to which VLAN. Think of VLANs as subnets at the logical level. Creating VLANs mean that to communicate between different VLANs, you need a router. Now here are more considerations; some managed L3 switches can act as a router (not full-blown) so that you can save $ on buying routers for each VLAN. A couple of ways to create VLANs and not all switches support all: based on MAC, based on protocol, based on switch port a PC/server connects to, based on user-defined settings (VLAN tagging).

2) Managed L3 switches have backplane forwarding rate. Say there are 48 ports and backplane forwarding rate is 32 Gbps, packets will be dropped/blocked/queued when a situation occurs where ALL 48 ports are utilizing full capacity at 1Gbps becoz all ports are connected to backplane and backplane can only forward 32 Gbps max.

3) Other features: 802.1x, Power-over-ethernet (you may need this), QoS (need it if you plan to have VoIP, streaming media, etc.)

For your question, given price difference is not high, I will definitely go with HP. Generally, D-Link brand is consumer class where HP is for Business/Enterprise class. You can consider Dell switches too. Of course, the best is Cisco. When you select a L3 managed switch, cheaper model means lesser features