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Clearing & Reloading the Router
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Clearing Existing Router Configuration

Because the pod consists of actual routers, there's a good chance that the routers will contain existing
configurations that might cause problems for a new scenario. It's generally a good idea to clear the
startup configuration of each router prior to beginning test. Of course, this is not a good idea on "live"
production equipment, but it works well for our purposes.

r3 has been used in the examples that follow. The same basic procedures apply to all five routers.

To erase the existing configuration, follow these steps:

1. First, access the router using the normal procedures:

[shelluser ~]$ r3  
Negotiating binary mode on output.
Connected to termserver.
Escape character is '^]'. Router>

2. Next, enter privileged mode (enable) and erase the existing configuration:

Router#erase startup-config
Erasing the nvram filesystem will remove all files! Continue? [confirm]y[OK]
Erase of nvram: complete Router#

Restart (reload) the router

3. Reload the router to eliminate any remaining configuration from memory. Do not save the
configuration if prompted to do so. We want an empty configuration on restart.
Note that the router restart process can take several minutes to complete. Be patient.

System configuration has been modified. Save? [yes/no]: no
Proceed with reload? [confirm]y
00:08:52: %SYS-5-RELOAD: Reload requested
System Bootstrap, Version 11.0(10c)XB1, PLATFORM SPECIFIC RELEASE SOFTWARE (fc1)
Copyright (c) 1986-1997 by cisco Systems
2500 processor with 14336 Kbytes of main memory

Notice: NVRAM invalid, possibly due to write erase.

F3: 7509084+107268+573328 at 0x3000060 [... additional boot messages ...]

Cisco Internetwork Operating System Software
IOS (tm) 2500 Software (C2500-I-L), Version 12.1(2), RELEASE SOFTWARE (fc1)
Copyright (c) 1986-2000 by cisco Systems, Inc.
Compiled Tue 09-May-00 19:57 by linda
Image text-base: 0x0303E424, data-base: 0x00001000

cisco 2521 (68030) processor (revision K) with 14336K/2048K bytes of memory.
Processor board ID 10353997, with hardware revision 00000003
Bridging software.
X.25 software, Version 3.0.0.
Basic Rate ISDN software, Version 1.1.
1 Token Ring/IEEE 802.5 interface(s)
2 Serial network interface(s)
2 Low-speed serial(sync/async) network interface(s)
1 ISDN Basic Rate interface(s)
32K bytes of non-volatile configuration memory.
8192K bytes of processor board System flash (Read ONLY)

4. On restart, you will be asked if you wish to proceed through the initial configuration dialog. You may enter a base configuration at this time, but generally it's easiest to skip this step.

--- System Configuration Dialog ---

Would you like to enter the initial configuration dialog? [yes/no]: n

5. The router will complete the initialization process, and eventually return control to you. Press ENTER a few times until you get the Router> prompt. The exact display shown will depend on the router in use.

Press RETURN to get started!
00:00:05: %LINK-3-UPDOWN: Interface Serial0, changed state to up
00:00:05: %LINK-3-UPDOWN: Interface Serial1, changed state to up
[... additional interface messages ...]
00:02:07: %LINEPROTO-5-UPDOWN: Line protocol on Interface TokenRing0, changed state to down
00:02:07: %SYS-5-RESTART: System restarted --
Cisco Internetwork Operating System Software
IOS (tm) 2500 Software (C2500-I-L), Version 12.1(2), RELEASE SOFTWARE (fc1)
Copyright (c) 1986-2000 by cisco Systems, Inc.
Compiled Tue 09-May-00 19:57 by linda Router>

6. At this point, the router is running in a minimal configuration with no interfaces enabled. You can now enter configuration commands directly, or copy an existing configuration using cut and paste, or tftp.