Installation guide

Making External Connections to Cisco 4000 Series Routers 4-47
Preparing to Make Connections
If the BRI module in Figure 4-1 were replaced by a second Ethernet module, the unit
addresses would be as listed in Table 4-2.
Table 4-2 Unit Numbering for Serial and Two Ethernet Modules
Figure 4-2 shows a chassis configured with three Ethernet modules.The unit numbering of
these modules would be as listed in Table 4-3.
Table 4-1 Unit Numbering for Serial, Ethernet, and ISDN BRI Modules
Slot Number Interface and Ports Unit Address Number
1 Serial port (labeled port 3)
Serial port (labeled port 2)
Serial port (labeled port 1)
Serial port (labeled port 0)
3
2
1
0
2 Ethernet port (top)
Ethernet port (bottom)
1
0
3 BRI port (labeled port 3)
BRI port (labeled port 2)
BRI port (labeled port 1)
BRI port (labeled port 0)
3
2
1
0
Slot Number Interface and Ports Unit Address Number
1 Serial port (labeled port 3)
Serial port (labeled port 2)
Serial port (labeled port 1)
Serial port (labeled port 0)
3
2
1
0
2 Ethernet port (top)
Ethernet port (bottom)
1
0
3 Ethernet port (top)
Ethernet port (bottom)
3
2