I am considering connecting two (and possibly three) HP Procurve 1800 switches together with trunks or with LACP. I can't find any substantial answer to my questions via Google or here.
I did find this question Server-to-Switch Trunking in Procurve switch, what does this mean? but the answer to the question seems to be: a) Trunking could mean anything; and b) LACP is defined. The question Is a Trunk or LACP preferred? is not answered - and it is not switch-to-switch but switch-to-server.
I also found this question LAN Design Question with HP Procurve but it also does not answer the question posed above: Is a Trunk or LACP preferred? In any case, this question is relevant to the HP Procurve 2510 and not the HP 1800.
Neither of these questions seem to discuss our exact situation. There are three switches (all HP 1800s):
SW1(VLAN1) <-> SW2(VLAN1) <-> SW3(VLAN1) SW2(VLAN6) <-> SW3(VLAN6)
The switches are all HP 1800-24G (Hardware Version R01) with the following Software Versions:
- SW1: PB.03.01
- SW2: PB.03.01
- SW3: PB.03.04
The links between switches SW2 and SW3 all allow Tagged Packets only and have no PVID (according to the help documentation's recommendations). Other ports are either VLAN 1 or VLAN 6, and allow All Packets. All ports are autonegotiate except the occasional 100Mb Full Duplex settings; others are all 1Gb - none are 10Mb.
The problem is that SW2 seems to not respond to pings quickly and often loses packets (as monitored from the monitoring host on SW3). Other switches are fine and respond appropriately. Connection between hosts seem okay. HTTP response from both SW1 and SW2 on their management interfaces seem slow - slower than SW3.
I suspect a traffic bottleneck and would like to create a bigger pipe. The pings are to the IP address of the switch, and connections to the HTTP port also show slow response times. Presumably, the connections (HTTP and ICMP) are on VLAN1 as that is where the IP would be - and VLAN1 is the management VLAN anyway.
From reading other questions, it sounds like a "trunk" would make it possible to combine the traffic for both VLANs on the same wire - reducing the two connections down to one, or make the traffic go across multiple wires for multiple VLANs. It also sounds like trunks can be combined with LACP, but is that desirable?
- Is a trunk or LACP preferred in this situation? Why?
- What does HP call a "trunk" in this situation?
- How should the VLANs be handled in this situation?
- Am I trying to solve the wrong problem?
- Would a firmware upgrade help?
I'd like an answer to all questions in any case.
UPDATE I forgot to mention that I found this web page which seemed helpful, but also did not answer my questions directly. It sounds like (from the answers there) that trunking is for switch-to-switch communication and LACP is for server-to-switch communication.