I am a software engineer and no one in my team is familiar with network setup. My team recently bought 20 PCs for test our software but we only have 2 ports left in the room. And I have suddenly come to take responsibility to setup. Before I request a help from network team, I want to setup them by ourselves first.

I borrowed the Layer-3 Network switch from another team for couple of days to proof setup(HP 5500 HI series - JG311A). I have tried some setup for few days but failed.

Requirement is simple. All corporation computers should be able to access the test PCs by IP addresses, so all PCs should have individual IP addresses. The company provides DHCP, but we can also ask static IPs for all 20 PCs.

Can I test this with the current Layer-3 switch? If can, how? (I know how to use console and commands)

  • 2
    "Before I request a help from network team, I want to setup them by ourselves first.". Why? This is a terrible idea. – JFL Jan 16 '18 at 7:53
  • Removed the off-topic request for product or resource recommendations. – Ron Maupin Jan 16 '18 at 15:11
  • @JFL Because it goes too slow to get a support from the network team because we are located in remote side. Sorry for lack of details. – Jonas Hong Jan 17 '18 at 0:54
  • Did any answer help you? If so, you should accept the answer so that the question doesn't keep popping up forever, looking for an answer. Alternatively, you could provide and accept your own answer. – Ron Maupin Feb 21 '18 at 18:17

You'll need to describe what goes wrong. Essentially, any switch can be used to connect a couple of PCs to a single port, no special setup required.

If your company policy does allow you to configure network devices:

With a managed switch like a HPE 5500HI the only thing you must set up is the password.

The most simple setup is to connect only a single port to the uplink switch. Connecting both ports requires at least (R)STP to be active on both switches, STP will block one of the ports, however, so there's little gain.

Connecting both ports so that they are active requires link aggregation setup on both switches, either static (no protocol) or dynamic (LACP). Connecting two links between two switches without anything set up creates a bridge loop causing a broadcast storm that likely brings down the network.

If both STP and LACP are no options you can split the switch in two using VLANs. Configure one half of the ports untagged for VLAN 1 and the other half untagged for VLAN 2. Make sure GVRP/MVRP are not activated. Now you can connect one port of each VLAN group to one of the uplink ports without causing a loop. Obviously, this is not good practice but this seems to be a temporary situation.

With DHCP, the pool needs to have enough free IP addresses. If this is not possible, things will get much more complicated. You'd need to create a new subnet with its own DHCP server and routing to and from the rest of the network. If this isn't possible either you'll need to set up a NAT router.

  • I tried the simplest one and the vlan one and both worked only for one downlink PC. The others connected later were not able to get proper DHCP config or be connected with static IP setup. By the way your comment was really helpful. – Jonas Hong Jan 18 '18 at 1:44
  • Have you verified that the switch is in factory default config? With various VLANs (e.g.) set up it can't work. – Zac67 Jan 18 '18 at 7:31

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