Strange behavior: device networking ok, but lost networing after start generate vlan traffic.

Hi guys,

I've a strange behavior just after start generate vlan traffic from a specific NIC.

I setup a test enviroment, with an ERPoe-5, a virtualization host, two virtual guest and one laptop to admin and testing the setup.

  - ERPoe-5 setup with default WAN2-LAN2 wizard configuration
  - ERPoe-5 built-in switch(eth2,eth3,eth4) has setup taged vlan20, vlan30, and default untaged vlan1 (10.10.10.0/24)
  - ERPoe-5:eth2 has connected the testing laptop via a vlan aware nic
  - ERPoe-5:eth4 has connected the virutalization host via vlan aware nic: 
      * vlan20 10.10.20.0/24 (virtualization servers network) 
      * vlan30 10.10.30.0/24 (virtual guests network)

Server and virtual guests works properly on their respective vlans, ERPoe-5 seems to work properly, no problems.

But I've a strange problem with the laptop. I can properly setup the eth0 laptop interface for default untaged vlan1 and for example the taged vlan 8 to communicate with server. In first time, no problems in setup and all seems to work properly, I can ping from laptop to all networks and devices, ICMP packets are traveling ok. Normal traffic at untaged lan works properly, I can access to http configuration service on ERPoe-5 and ssh to any host.

But if I try use taged vlan8 I have this strange behavior: I can properly ping from laptop to all subnetworks, works perfectly as I said, but if I try normal traffic as access to http services or ssh, something goes wrong, networking stops work properly, and NO ping can be due after that, any gateway or device at any network are unreachable, no ICMP packets and no normal packets, all are unreachable.

All problems just after I try to use taged vlan, before that all works ok. The problem are focused on laptop networking, not entire network. After restart laptop or network NIC, all works properly again, I can ping and generate normal traffic, until I make a normal traffic (not ICMP) request within a vlan taged network.

I tried stop iptables and downsize the MTU, but not lucky.All seems to be a problem on laptop NIC side, sure not ERPoe-5 issue. I would ask for your wide experience if know why about this behavior is produced. Or if you can give me some steps to try fix or locate more precisely where is the problem.

Thank you guys!!