SG200-26 26-Port VLAN Nightmare

thefrankie63 · ‎01-24-2016

Hi it is almost 3 days I'm trying to configure VLANs on this switch, hope someone may help.I asked friends and Cisco users but I decided at the end to use the community to try to sort out issues.

I've several of these switches at customer sites, they work well but in a couple of customer premises I need to implement VoIp, so I need to implement VLAN to separate and prioritise VoIp traffic. In all sites there several devices, all in the same subnet 192.168.x.x/24, in the subnet are present several systems, between them: DHCP, DNS, SIP PBX server, Firewall ...

The switch has been upgraded to last firmware: 1.4.1.3.

I googled, red a lot of forums and started from the Cisco video here: https://www.youtube.com/watch?v=pP0g89v0y2g, in the 3 minutes video a Voice VLAN has been created. The Voice VID is 100 and all phones are configured as 1UP, 100T and the uplink port is 1UP, 100T. This configuration works but some questions bounce in my mind:

Phones are not isolated, any computer in LAN (1U configured) can ping and access phone web server interface, how can I protect traffic between VLAN ?
Since phones are not configured to use VLAN ID, yet, no frames coming from phones has VLAN info on it seen using Wireshark on a port mirror, how the switch recognises 802.1q frames and assigns VLAN ? I suspect all traffic goes on VLAN 1.
On the same video, there is a GE10 port connected to a Lobby, the phone port is configured as 100UP, I tried to connect a phone using this configuration but the phone cannot talk to DHCP, DNS and SIP server on the LAN, simple unusable. Should I configure the port where DHCP, DNS, SIP server s 100T, 100U ? I tried with no luck.

I saw also a forum post here: https://supportforums.cisco.com/discussion/11797251/vlan-setup-sg-200-26p, port 2 is configured as 1U, 2UP but using 1U is impossible since VLAN 1 is default VLAN and 1U without P is impossible to use, if I change the default VLAN if I need to manage the switch I need to put also configuration PC on a new VLAN.

After all the above tries I start to read documentation and manuals, Cisco and not and

I realised that my router is not a Level 3 Relay but a Level 2, so different VLANs can't talk each other.
I also did put some ports Tagged but tag doesn't exit from port.

I've also some suspect that Web GUI has problem, for my tests I moved interface in General mode but I can't move back to Trunk or Access since I obtain always the error: Acceptable frame type value is only supported in GENERAL mode. I'm going to reset to factory setting my switch and restart testing.