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VLAN Interface

RansNet routers support IEEE 802.1Q VLANs, allowing a single physical interface to be divided into multiple logical sub-interfaces. Each sub-interface is tagged with a VLAN ID and operates as an independent Layer-3 interface with its own IP address.

VLAN Architecture

In the diagram above, eth1 carries three tagged VLANs (vlan20, vlan30, vlan40) over a single trunk link to a downstream switch. Each VLAN sub-interface is presented to the Kernel FIB as a separate routed interface, while eth0 remains a standard untagged Layer-3 uplink.

Prerequisites

Before configuring VLAN interfaces, ensure the following:

  • The parent physical interface (eth0, eth1, etc.) must be enabled
  • The connected peer port (e.g., upstream switch port) must be configured as an 802.1Q trunk with the relevant VLANs permitted
  • Each VLAN sub-interface requires its own IP address assignment
  • Physical interfaces are in VLAN 1 by default (untagged)

Note

VLAN interfaces bridged to wireless interfaces operate in bridge mode rather than pure routing mode.

GUI Configuration

Navigate to Device Settings → Network → Interfaces, then click + Add Interface and select VLAN (Sub-interface).

Add VLAN Interface

Once you're in the VLAN interface edit mode, set the VLAN interface name (format: vlan + VLAN ID, e.g., vlan19) and select the parent physical interface.

Add VLAN Interface

Settings

Field Description
VLAN Interface Name Logical name for this sub-interface, formatted as vlan + VLAN ID (e.g., vlan19, vlan100). This determines the VLAN tag used on the wire.
Main Interface Parent physical interface this sub-interface is created on (e.g., eth1)
Admin Status Enable or disable this sub-interface
IPv4 Address Set to Static IPv4 Address to manually assign, or DHCP to obtain from upstream. Multiple IPs can be added via + Add IPv4 Address/Prefix.
IPv6 Address IPv6 address assignment (optional)

Other Settings:

Option Description
Bond Mode Include this VLAN in a link aggregation bond
DynDNS Enable Dynamic DNS updates for this interface's IP
Enable Tracking Enable interface tracking for link-state or VRRP monitoring
MTU Override MTU for this sub-interface (default: 1500)
Proxy ARP Enable Proxy ARP so the device responds to ARP requests on behalf of hosts on other subnets
Bridge Bridge this VLAN to a wireless SSID or other interface (operates in Layer-2 bridge mode)
VRRP (High Availability) Configure VRRP for gateway redundancy on this VLAN
Route Metric Administrative metric for routes via this interface
Netflow Export Enable NetFlow traffic export on this interface
VRF Assign to a VRF instance for traffic segmentation

CLI Configuration

Enable parent interface and create VLAN sub-interfaces

The CLI syntax for a VLAN sub-interface is:

interface vlan <parent-port-number> <vlan-id>

For example, interface vlan 1 20 creates VLAN ID 20 on eth1 (port 1).

Multiple VLANs on the same physical interface

interface eth1
  enable

interface vlan 1 10
  description "Management VLAN"
  enable
  ip address 192.168.10.1/24

interface vlan 1 20
  description "Data VLAN"
  enable
  ip address 192.168.20.1/24

interface vlan 1 30
  description "IoT VLAN"
  enable
  ip address 192.168.30.1/24

Verification

show interface vlan1

Example output (below vlan1 is bridged to wireless SSIDs)

  ================================================================================
  Interface : br-vlan1
================================================================================

  Network Information
  ----------------------------------------
  Admin State            : UP
  Link State             : UP
  MAC Address            : ee:ce:65:2f:34:2a
  MTU                    : 1500 bytes
  IPv4 Address           : 10.18.18.1/24
  IPv4 Broadcast         : 10.18.18.255
  IPv6 Address           : fe80::ecce:65ff:fe2f:342a/64 [link]

  VLAN Information
  ----------------------------------------
  VLAN ID                : 1
  Parent Interface       : eth1
  RX Frames              : 1272581
  RX Bytes               : 189871757
  RX Multicast/BC        : 52700
  TX Frames              : 1084385
  TX Bytes               : 308633299

  Bridge Information
  ----------------------------------------
  Bridge ID              : 7fff.eece652f342a
  STP                    : Disabled
  Member Interfaces      : ath0 ath01 ath1 ath11 vlan1

  Physical Information
  ----------------------------------------
  Link Detected          : yes

================================================================================

To view all interfaces including VLAN sub-interfaces:

show interface