User guide

Chapter 4
Physical and Layer 2 Interfaces
This Chapter
This chapter introduces the physical and logical interfaces available on the base
unit router and the optional interfaces available as expansion options for the
PIC bay. Topics covered are:
■
“Interfaces” on page 42
■
“Naming Interfaces” on page 43
■
“Ethernet Ports” on page 44
■
“Asynchronous Port” on page 44
■
“Synchronous Ports” on page 46
■
“Switch Ports” on page 46
■
“Virtual LANs” on page 48
■
“Point to Point Protocol (PPP)” on page 49
■
“Frame Relay” on page 50
■
“Integrated Services Digital Network (ISDN)” on page 53
■
“Configuring ISDN” on page 55
■
“Installing Port Interface Cards (PICs)” on page 62
Once you have configured the Layer 2 interfaces, you can configure a Layer 3
protocol to route traffic between these interfaces. A simple network overview
showing the relationship between physical interfaces, data link protocols, and
network routing protocols is shown in Figure 4 on page 42.