I own:
- 3 switches (layer 2, managed, 24 ports) model Zyxel GS1920-24HP
- 1 router model Zyxel USG 310
My network is segmented into 10 VLANs (1, 2, 3, 4, 5, 6, 7, 8, 10, 11), the central router routes packets between different VLANs (passing from an SPI firewall), from VLANs to Internet and vice versa (passing from an SPI firewall) and from VPNs to some resources on VLANs and Internet. Each VLAN has a subnetmask of 255.255.255.0 with netrange 192.168.X.0 / 24, where X is the VID specific to the VLAN, the router have always address 192.168.X.1 on each VLAN.
Switch1 is located in a second room, while the other 2 in the central rack, where the router is also located.
Switch1:
- connected devices: VLAN5
- switch management: VLAN1
- network communication ports: 2 Gb in LAG
Switch2:
- connected devices: VLAN2, VLAN3, VLAN4, VLAN6
- switch management: VLAN1
- network communication ports: 2 Gb in LAG
Switch3:
- connected devices: VLAN1, VLAN5, VLAN7, VLAN8, VLAN10, VLAN11
- switch management: VLAN1
- network communication ports: 2 Gb in LAG
Router:
- port1: bridge VDSL2 modem (PPPoE session to Internet)
- port2: bridge VDSL2 modem (PPPoE session to Internet)
- The 2 PPPoE sessions are independent and serve different VLANs.
The only VLANs that are replicated in multiple switches are: - VLAN1 which is used to manage the switches from their administration interfaces - VLAN5 which has only 1 device not connected to the switch1 but to the switch3 (for logistic reasons of wiring).
I have two different connecting solutions:
Solution1:
- switch1 LAG1 -> switch3 LAG1
- switch2 LAG1 -> switch3 LAG2
- switch3 LAG3 -> router LAG1
Advantages: The router has on the LAG1 port the 10 VLAN interfaces and don't create VLANs interfaces replication.
Example) LAG1/1, LAG1/2, LAG1/3, LAG1/4, LAG1/5, LAG1/6, LAG1/7, LAG1/8, LAG1/10, LAG1/11
Disadvantages: This solution increase network traffic and latencies because if a VLAN2 device connects to a VLAN3 device the connection follow this flow:
switch2 -> switch3-> router -> switch3 -> switch2.
Solution2:
- switch1 LAG1 -> router LAG1
- switch2 LAG1 -> router LAG2
- switch3 LAG1 -> router LAG3
How can I configure the same VLANs on different LAG ports?
Example) LAG1/1, LAG1/5
LAG2/1, LAG2/2, LAG2/3, LAG2/4, LAG2/6
LAG3/1, LAG3/5, LAG3/7, LAG3/8, LAG3/10, LAG3/11
Which solution should be adopted?
Thanks,
Berto.