The interface panel#
Clicking a row on Interfaces opens a side panel. Its settings start as the
router has them; Save changes adds what you changed to the pending changes and closes
the panel, and the Commit Bar applies them. Esc closes the panel and drops what was
typed. In Advanced mode the panel also shows the commands Save changes will stage.
Status and Traffic#
Read-only, from what the router reports now.
| Field | Meaning |
|---|---|
| Status | Up, Down or Unknown |
| MAC address | the address the port uses now |
| MTU | the MTU in force now, which is not necessarily the configured one |
| Addresses | every address the router holds on it, link-local ones included |
| Received, Sent | bytes and packets since the interface came up |
| Receive errors / drops, Send errors / drops | a rising receive count points at cabling or a duplex mismatch; drops on a shaped interface are how the shaper signals congestion |
Advanced mode adds the kernel's link flags and queue discipline.
Settings#
| Setting | What it does |
|---|---|
| Description | free text; the Description column, and the label beside an uplink |
| Addresses | the static addresses, each with its prefix length: add one in the box, remove one with its ×. See Addressing |
| Address from DHCP, IPv6 address from DHCPv6 | the router asks for an address on this interface. On Ethernet ports, bonds, bridges and VLANs |
| MTU | in bytes, 68 to 16000; empty is the default, 1500 |
| MAC address | on Ethernet ports, bonds and bridges: the address the port uses instead of its hardware address. For an ISP that serves only the MAC address of the router it replaced. Empty uses the hardware address, shown in the field |
| Disabled | the link goes down, every address on it stops answering, and every route through it is withdrawn |
A value that the router would refuse — an address without a prefix length, a MAC address with five parts — is named under its field and Save changes stays disabled.
Bridge#
On a bridge:
- Member ports lists its ports. Remove one with its ×, or add one from the list. The list offers only ports that can join: no address of their own, in no other bridge or bond, and not one of this bridge's own VLANs. When the bridge carries VLANs, a port added here carries them too.
- Spanning tree turns the spanning tree protocol on or off. Turn it on when the bridge could form a loop with a switch.
Bond#
On a bond:
- Mode is how the ports share traffic: LACP (802.3ad, the default), active backup, balance by hash, round robin, transmit load balancing, adaptive load balancing or broadcast.
- Balance by, for LACP and balance by hash, is what chooses the port for each flow: MAC addresses (the default), MAC and IP addresses, IP addresses and ports, or the same inside a tunnel.
- Member ports works as on a bridge, and offers Ethernet ports only.
Hardware offload#
On an Ethernet port, the nine offload features the router can set, in two columns:
| Column | What it is |
|---|---|
| Configured | whether the configuration asks for the feature; the checkbox is the only thing you change |
| Active | what the network card reports it has on now: On, Off, or a dash |
Active is read once, when the panel opens, and again after a commit or when you press Read again; it is never polled.
A drift badge on a feature means the configuration asks for it and the card reports it off. The other way round is not drift: an unset feature is not a request for "off". A port that is not configured yet shows Active and no checkboxes, with a note saying so.
Deleting#
Delete interface (or Delete VLAN), pressed twice, removes the interface and everything under it.
A VLAN is deleted the way Networks deletes one, so it takes what it owns with it: its DHCP scope, the DNS forwarder's entries for it, its access policy, and its place on a bridge's ports. A VLAN that is a link rather than a network — an uplink on DHCP, a PPPoE carrier — is deleted on its own. A VLAN that is a network says so at the top of the panel, with a link to where its DHCP, DNS and access policy are edited.
Deleting does not change other settings that name the interface — a firewall rule, a NAT rule, a QoS policy. Change those too, or the router may refuse the commit.
See also#
- Interfaces — the table this panel opens from.
- Adding an interface — making a new one.
- Addressing — address values and MTU.
- Networks — a VLAN's DHCP, DNS and access policy.