Slow connection between VLANs on GS1915-24E

Xydocq

When I try to move a file from a Computer located on lan1 (port3 on the switch) to a NAS located on VLAN20 (port23 on the switch) the connection is very slow. I would say it's like 45% of max possible.

If the Computer is on the same VLAN everything works fine. Speed is at max level.

I was using a TP-Link switch before that had no issues with different VLANs like the GS1915 seems to have.

I use a USG Flex 200, with the switch and a NWA130BE as AccessPoint. So the problem has to be Zyxel related. The NAS is a Synology DS218.

Any help would be appreciated.

Zyxel_Kay

Hi @Xydocq

The GS1915-24E is a Layer 2 switch, which handles traffic forwarding but does not perform inter-VLAN routing. Based on your observation, where connections within the same VLAN work fine but slow down across VLANs, the issue might be related to the inter-VLAN routing process handled by your USG FLEX 200.

When traffic flows between VLANs, the packets must be routed through the firewall. During this process, the firewall analyzes each packet, which can add latency and consume system resources.

Zyxel_Kay

Hi @Xydocq

The GS1915-24E is a Layer 2 switch, which handles traffic forwarding but does not perform inter-VLAN routing. Based on your observation, where connections within the same VLAN work fine but slow down across VLANs, the issue might be related to the inter-VLAN routing process handled by your USG FLEX 200.

When traffic flows between VLANs, the packets must be routed through the firewall. During this process, the firewall analyzes each packet, which can add latency and consume system resources.

Xydocq

Hi @Zyxel_Kay

Thank you for the information.

I kinda figured that out myself, shortly after posting here.

I connected the NAS to the USG with the same speed result as it was when it was plugged in to the switch. It would be nice to be able to disable packet-inspection on the USG for VLAN-traffic. I thought the firewall-rules would disable such a thing, guess I was wrong.