3COM Series 5500 VLAN Questions

[chris2016]

Dear All,

I'd like to setup VLANs on some 3Com Series 5500 switches. We already have STP enabled. I've read a lot on the internet, but I'm not sure if I understood everything correctly.

1. Can I use VLAN ID 1 for computers on the network, that is on access ports? The configuration guide says I shouldn't, but unfortunately gives no reason. Furthermore, the same guide says, a trunk port couldn't be added to VLAN 1. Why not? Is VLAN 1 always untagged? Some websites suggest untagged VLAN 1 was required for STP? Is this implicated anyhow?

2. Configuration guide: "a trunk port only allows the packets from the default VLAN to be sent without tags." Is "default VLAN" VLAN ID 1 or is it the PVID specified on the trunk port?

3. To quickly setup some guest Wifi access points: is it possible to keep all machines untagged on VLAN 1, put the APs to VLAN-ID 1 untagged (management) and VLAN-ID 2 tagged trunks (guests, own SSID) and set the ports between the switches to trunk (VLAN-ID 1 untagged, VLAN-ID 2 tagged)? What would be the disadvantage?

Is there any 3Com documentation covering such questions? I've only worked with HP ProCurve and there you can just select in a table tagged / untagged / forbidden for each port and VLAN. That's much clearer. Although I haven't used STP then.

- Chris

[16again · Accepted solution]

-1 You can still use VLAN1 for end devices.  Recommendation not to use VLAN is mainly security (example prevent VLAN hoppping)
-2 On trunk port, only a single VLAN can be untagged. Default this is VLAN1, indeed you can alter with PVID
-3 Your suggested config will work fine

Most H3C comware switches have detailed manual. Config-wise, they're more like Cisco switches.
Studying Cisco exams gave me solid understanding of network foundation, which comes in handy when touching other vendors stuff.

[chris2016]

Thank you very much! This is exactly what I was looking for. I'll get the cisco exams.

- Chris