How do I verify VLAN tagging on a dedicated server?
VLAN connectivity requires agreement between the server interface and the adjacent switch or provider network. A VLAN ID configured only on one side may isolate the server. Identify whether the service expects tagged traffic, an untagged access network or a bridge with VLAN filtering before changing anything.
Before you start
- Authorised access to the dedicated server and the named inspection tools.
Instructions
1. Inspect the VLAN interface definition
Use the actual interface name from the deployed configuration. The sample naming convention is common but not required.
ip -d link show dev enp1s0.100The detailed output identifies the VLAN ID and parent link. The name itself is not proof of the configured tag.
2. Check address placement and the physical path
Compare the VLAN interface, any bridge/bond layers and the provider’s assigned VLAN. The operating-system address should be on the interface intended by the network design.
ip -br address
ip -br linkDo not move the management IP between parent and VLAN interfaces without console access and a reviewed network plan.
Check the result
- The host tag, parent link, switch/provider assignment and IP route all match, and a permitted endpoint on that network is reachable.
Troubleshooting
- The VLAN interface is up but traffic fails
- Check switch tagging, allowed VLANs, parent-link state, MTU and destination routing.
- A bridge carries the VLAN
- Inspect bridge VLAN membership and filtering as well as the VLAN subinterface; the design may use either or both layers.
Official references
Use the documentation for your installed version when a flag, service name or platform feature differs.