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Frame Relay Protocols 539
Layer 3 Addressing
This section examines three cases of Layer 3 addressing when using Frame Relay. Figure 8-11
starts the first case with an illustration of a fully meshed Frame Relay network. In a full mesh,
each router has a direct connection to every other router, allowing the Frame Relay cloud to be
treated as one Layer 3 network. Figure 8-11 also shows IPX and IP addresses. The IPX and IP
addresses would be configured as subcommands on the serial interface. Table 8-13 summarizes
the addresses used in Figure 8-11.
Figure 8-11
Full Mesh with IP and IPX Addresses
The second case is a partially meshed Frame Relay network (see Figure 8-12). Because all four
routers do not have VCs to each other, each VC uses a different set of Layer 3 groups. Table
8-14 shows the IPX and IP addresses for the partially meshed Frame Relay network illustrated
in Figure 8-12. The addresses would be configured as subcommands on the serial interface.
(Note: The notation /24 signifies a subnet mask with 24 binary 1s--in other words,
255.255.255.0.)
Table 8-13
IP and IPX Addresses, with No Subinterfaces
Router
IP Address of
Frame Relay
Interface
IPX Network of
Frame Relay
Interface
IPX Address
Mayberry
199.1.1.1
199
199.0200.aaaa.aaaa
Mount Pilot
199.1.1.2
199
199.0200.bbbb.bbbb
Raleigh
199.1.1.3
199
199.0200.cccc.cccc
Mayberry
Raleigh
Mount Pilot
199.1.1.1
192.0020.AAAA.AAAA
199.1.1.3
199.0020.CCCC.CCCC
199.1.1.2
199.0020.BBBB.BBBB
s0
s0
s0
Frame Relay
Full Mesh
ch08.fm Page 539 Monday, March 20, 2000 5:17 PM