InterVlan Speed Issue

[hamel-d]

I built a VLAN between a Cisco SX350X-24F using 10 GB fiber to the other switch which is a Cisco SG500X-48.   I have VLAN 1 default and I built VLAN 16 .   The VLAN works fine, I can ping, login etc.   The problem I am having is a computer on VLAN 1 connected to a Server on VLAN 1 will read/write at excellent speeds.     But if I connect from VLAN 16 to to the same server on VLAN 1 the speeds are cut in half.   Speeds on equipment connected to VLAN 16 and a Server on VLAN 16 are fast as well.  It just connecting from VLAN 1 to 16 or the other way?    I've been out of switching and routing for awhile, but it seems I am missing an element in the configuration?     The Gateway where the DHCP is at is a SonicWall NS-4650 on a 10 GB Ethernet Port as well.

Thank you

[Joseph W. Doherty]

So what's the routing device, and where is it in relationship to your two VLANs?

[hamel-d]

SonicWall NS-4650 is the Gateway and Hands Out IP addresses on both VLANs.  ---> Connects to the SX350X through 10 GB fiber ---Then Port 1 of the SX350X --- Connects via 10 GB fiber to the remote SG500X 

[hamel-d]

Here is a quick scenario

[Joseph W. Doherty]

Hmm, just found this:

SonicWall NSA 4650 Network Security Appliance

The SonicWall NSA 4650 secures growing medium-sized organizations and branch office locations with enterprise-class features and uncompromising performance.

• Firewall Inspection Throughput: 6.0 Gbps
• Full DPI Throughput: 3.0 Gbps
• IPS Throughput: 2.3 Gbps
• VPN Throughput: 3.0 Gbps

Unclear what the device's routing performance is, but if it's the device doing the routing between your VLANs, and you see a noticeable difference between L2 transfers vs. L3 transfers, the L3 routing device could very easily be the reason for the lessor performance.

[hamel-d]

I disabled DPI LAN to LAN, also had a tech call with SonicWall.  I am going to try and build 2 VLANs on the Cisco SX350x at layer 3 and have the remote SG500x switch hand out DHCP and see if that makes a difference.  If it does then I can point to the SonicWall as the issue.