You must ensure promiscious mode is enabled on the port group you’ve assigned to the vmnic on the GNS3 VM. This is achieved by setting the VLAN ID to “All (4095)”Įnabling Promiscuous mode on the port group You will also need to ensure the port group is configured to permit all vlan’s. There is no need to add vlan’s that you intend to use with the cloud link as tagged frames passed from the GNS3 cloud to the host’s Ethernet port will be forwarded to the VMware vSwitch, as long as 8021q is enabled on the kernel detailed earlier in this post. You only need to configure a vlan at the host level for management of the VM. With many VM’s this could become annoying each time you upgrade GNS3 you need to reconfigure the networking settings on each VM 🙁

I’m hopeful that one day the GNS3 team will prevent the networking configuration from being overwritten during upgrades. Please note, you’ll need to keep a record of your interface configuration as when you update the GNS3 VM the networking is overwritten. This approach requires a vlan be created on the VM at the host level in the below example the interfaces file on GNS3 VM was modified to create a vlan 31: sudo nano /etc/network/interfaces A single vmnic was assigned to each GNS3 VM for both management of the VM and for 802.1q traffic to the VMware vSwitch. You could use another vmnic to handle your 802.1q connections but I prefer to use a single vmnic where possible. To load it permanently so it survives reloads of the VM: sudo su -c 'echo '8021q' > /etc/modules' Load 802.1q into the kernel: sudo modprobe 8021q Enabling 802.1q on the GNS3 VMįirst install vlans on the GNS3 VM: sudo apt-get install vlan That approach doesn’t scale well, especially if your trying to emulate a complex topology with many vlans. When researching how to present multiple vlans to the GNS3 VM, I discovered some people use a vmnic per vlan. As long as your using VMware compatible network adapters 802.1q works fine with ESXi.

Recently I needed this work so I thought I’d give it a go running the GNS3 VM on ESXi. From my research I believed the issue to be due to the network interface card / drivers not supporting / stripping the 802.1q vlan tags. I’ve been using the GNS3 VM on VMware Workstation for years, so far I’ve been unable to get virtual devices on the GNS3 VM to link to external networks using 802.1q. This post details my experiences getting the GNS3 VM on ESXi to work with 802.1q.

Can39t connect to gns3 vm