Filter
Top Products
Chapter 6 - Configuring Ethernet Interfaces
Chapter 6 - Configuring Ethernet Interfaces
Introduction
This chapter familiarizes the user with:
• Reading the Ethernet LEDs
• Configuring Ethernet Network Interfaces
• Configuring VLANs
• Configuring PPPoE
Ethernet Interface Fundamentals
RuggedCom manufactures dual Ethernet Interface boards in a variety of formats.
Some (most notably the optical interfaces) have the same outward appearance but
different order numbers. A complete set of descriptions is displayed on the console
during boot and can be found after boot in the file /var/cache/ruggedrouter/inventory.
LED Designations
The RuggedRouter includes two sources of LED indicated information about Ethernet
ports, the front panel LEDs and the LED Panel.
A LED is associated with each port, next to the Ethernet interface RJ45 socket. This
LED is off when the link is disconnected, remains solidly on when the link is
established and flashes briefly from on to off when traffic occurs.
The LED Panel also summarizes this information. LEDs 1-4 reflect traffic on
Ethernet port 1-4. LEDs 5-8 reflect the link status of the same ports.
VLAN Interface Fundamentals
A virtual LAN (VLAN) is a group of devices on one or more LAN segments that
communicate as if they were attached to the same physical LAN segment. VLANs are
extremely flexible because they are based on logical instead of physical connections.
When VLANs are introduced, all traffic in the network must belong to one or another
VLAN. Traffic on one VLAN cannot pass to another, except through an intranetwork
router or layer 3 switch.
The IEEE 802.1Q protocol specifies how traffic on a single physical network can be
partitioned into VLANs by “tagging” each frame or packet with extra bytes to denote
which virtual network the packet belongs to.
VLAN Tag
A VLAN tag is the identification information that is present in frames in order to
support VLAN operation. If an Ethernet frame is VLAN tagged, the EtherType value
(immediately following the Source MAC address) is set to 0x8100, denoting 802.1Q
(VLAN). The next 2-bytes of the VLAN tag contain: a 3-bit User Priority Field that
may be used as a priority level for Ethernet frames, a 1-bit Canonical Format Indicator
(CFI) used to indicate the presence of a Routing Information Field (RIF), and finally
the 12-bit VLAN Identifier (VID) which uniquely identifies the VLAN to which the
Ethernet frame belongs. These four bytes, known as the VLAN tag, are followed by
the rest of the Ethernet frame, starting with the length field.
RuggedCom 57