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Can't access IP after Factory Reset

Last Modified: 2013-02-11
We have a single Cisco 851W router, it was working fine until we needed to make a change and discovered we no longer had the passwords for it -- so we attempted the password recover procedure and lost everything.

Since the router no longer seem to be working we decided to restore Factory Defaults in the hopes of using the Cisco SDM GUI to reconfigure it after the fact.

We ran a "write erase" command followed by a "reload".

To our surprise this rest the router to a Factory Default which was not the same as the "Out-Of the Box" configuration.

Plugging a network cable into FE0 and setting my laptop to network settings of / using either a straight-through cable or a cross-over cable returns "Request timed out." when attempting to ping

I ran out to chapters bought a couple books in Cisco and have been scouring the net for instructions as to how to manually reconfigure the router to a minimum level such that I can ping it and then use the SDM software.

Please help and giving me an IOS set of script commands to configure my router to enable SDM access again?

The attached file contains a boot capture trace, a flash directory and the current configuration.

Watch Question

You should be able to do the following to get an IP address back on it.
From the Commnand line
conf t
interface FastEthernet40
 ip address

After this you should be able to telnet to it from FE0

oops, sorry. it should be

conf t
interface FastEthernet0
 ip address
I'll assume you already know how to log onto the router since you posted the running config.

To set the IP address you'll need to do the following:
enable     -   Enter's privilege mode
conf t      -    Enters configure mode
int fa0/0   -    Enter interface mode for fa0/0
ip add   - Set IP
no shut    - enable interface.

username iqualin password PASSWORD      - Set username for login
ip http server
ip http authentication local

line vty 0 4
privilege level 15
login local
transport input telnet ssh


When I try to do:

Router# conf t
Router(config) interface FastEthernet0
Router(config-if)  ip address

I get the error message:

% IP addresses may not be configured on L2 links.

I think it means that the FastEthernet ports are not real and its got something to do with Vlan1 configuration but that's just me reading from the books I bought last night.


When I try to do:

Router# conf t
Router(config) int fa0/0

I get the error message:

% Invalid input detected at '^' marker.

Where the ^ points to the / character.

If I drop the /0 and just use int fa0 I fail at the next line with the same L2 links error message.

int vlan 1
ip add x.x.x.x mask

what IOS version?


The IOS Version information and all other details are in the Trace.txt file attached in the original post.

I think the IOS Version is:
Cisco IOS Software, C850 Software (C850-ADVSECURITYK9-M), Version 12.4(4)T6, RELEASE SOFTWARE (fc2)

The flash ROM file name is:

You'll see in the configuration dump I have;
interface Vlan1
 ip address
Sorry its int fa0 not fa0/0

If you get a L2 error you will have to issue a no switchport command under fa0
Though vlan 1 will work as well.


I tried the following to no avail;
1) I issued a "switchport access vlan 1" under int fa0 -- still could not ping the port.
2) I issued a "no switchport access vlan 1" under int fa0 -- but it still gave me the L2 error when I tried to issue the "ip address" command.

I'm really not impressed with the router -- you'd think that returning it to factory defaults would mean the the FastEthernet port 0 would be configured for IP and ready for SDM access.

But, instead Factory defaults seem to return the unit to the useful equivalent of a "Paper Weight" with a serial interface where only the original developer can program it!!!

Sorry just venting.

my only expereince with the 800 series is replacing it with an ASA.  
Get rid of the dinosaur, spend $500 get an ASA 5505 which i will assume meets your requirements if you are currently using the 800 as your gateway device. I still use the 800 for wireless, at the clients site.

I see in the trace that the vlan 1 ip is
this means you would only be on the same subnet if your ip is .2-.6 is that whats causing you the problem?

which one of these ports is the outside interface?


My Laptop is configured with IP /
The laptop is direct wired from its ethernet port to the FastEthernet0 port and the serial/console cable is connected too to the laptop.  Nothing else is plugged into the Router.
sharedit, you have to issue "no switchport" with no arguments on the fa0
Sorry I meant to address that to jgaulin


donmanrobb, when I execute the following;
conf t
int fa0
no switchport

I get the error: % Incomplete command.

if it says incomplete command then hit a ? after the command to see your options

command ?

Try issuing "ip routing" from the config prompt then try adding the IP


Issued the "ip routing" but still get the L2 error when doing the "ip address" on int fa0.
Okay one last time we'll try the following:

no switchport mode access
no switchport
ip add

If that doesn't work try fa4 instead

Isnt this device fairly old? Im not familiar with the "no switchport" command on devices other than layer 3 switches.  This device is not a layer 3 switch, it is a very basic gateway/wireless/switch kind of like a linksys.

am i inncorect?

int vlan 1
no ip add
ip add "whatever"  mask

go into each interface and do no shutdown

put your laptop on the same subnet and try to ping.
try and ping from inside the router.

i dont think there are any no switchport commands, because each port ,with the exception of the gateway interface which i believe is FastEthernet4,  IS a switchport.

you would do a no switchpot command if you were going to assign a new routable subnet to the port, but that is only available on a layer3 switch.  

Im not 100% but i think you can abandon the no switchport.  I am fairly positive it is the VLAN interface that needs to be configured.


If any one is interested I can provide VNC access to the PC with the HyperTerminal session -- for a more hands-on approach?  Not sure if this is against EE rules & regulations?  Let me know and I'll post a temporary URL and PWD.
The command is most known on Layer 3 switches however in this case we have a Layer 3 router operating in layer 2, so its the same logic, though these ports might be permanent l2 ports so vlan1 might be necessary.
I'd like to have a look, email me the info :)

not as basic as a linksys, but you cant route between the switchports.


How do I email you through the EE interface?
You can't through the interface, just send off an email to donmanrobb@hotmail.com with the info


Email Sent -- it may end up in the hotmail SPAM folder since its from a Rogers mails server.
This one is on us!
(Get your first solution completely free - no credit card required)


Since I'm not a cisco export I don't claim to understand why a DECnet bridge group was or how it got into my Factory Default reset but I much appreciate donmanrobb's help in getting my SDM connectivity back up and running.
Does anyone know what the resolution was to this old post?  I am having the same issue with a newer Cisco881.


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