Port-naming in Cisco Router

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1. Naming Convention — The Rule

Cisco interface names are built from three parts (simple form used on many modular routers):

<Type><Slot>/<Port>

• Type = Ethernet, FastEthernet, GigabitEthernet, Serial, etc.

• Slot = the module slot number in the router chassis where the network module or WIC is inserted. Packet Tracer numbers these 0,1,2,... as you inserted modules.

• Port = the physical port index on that module (usually 0 for single-port modules; multi-port modules will show 0,1,2...).

Notes:

• Some platforms add a third number (e.g., GigabitEthernet0/0/0) — that’s slot/subslot/port on other platforms. For CCNA labs you’ll most often see Type slot/port.

• Subinterfaces use a dot: GigabitEthernet2/0.10 (common for router-on-a-stick / VLANs).

2) Map Your Modules → show output

You gave these module descriptions and the show ip int brief list. Here’s the direct mapping (based on slot number ordering Packet Tracer uses):

Module (your list)	Displayed interface name
PT-ROUTER-NM-1CE (single Ethernet)	Ethernet0/0
PT-ROUTER-NM-1CFE (single FastEthernet copper)	FastEthernet1/0
PT-ROUTER-NM-1CGE (single Gigabit with GBIC slot)	GigabitEthernet2/0
PT-ROUTER-NM-1FFE (single FastEthernet fiber)	FastEthernet3/0
PT-ROUTER-NM-1FGE (single Gigabit fiber/copper via GBIC)	GigabitEthernet4/0
Dual-serial WIC (two serial ports)	Serial5/0 (and Serial5/1 if the second port is enabled/seen)

So your show ip int brief matches exactly the modules in slots 0..5:

Router#show ip interface brief 
Interface              IP-Address      OK? Method Status                Protocol
 
Ethernet0/0            unassigned      YES unset  administratively down down
 
FastEthernet1/0        unassigned      YES unset  administratively down down
 
GigabitEthernet2/0     unassigned      YES unset  administratively down down
 
FastEthernet3/0        unassigned      YES unset  administratively down down
 
GigabitEthernet4/0     unassigned      YES unset  administratively down down
 
Serial5/0              unassigned      YES unset  administratively down down
Router#

Cisco Packet Tracer (Version 6.2.0.0052)

65KB

Port-naming-in-Cisco-Router.pkt

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