Cisco 881 vlan isolation, unknown interfaces, and basic configuration questions

[Joe Conklin]

Hello,

I've configured my router as needed and everything is working. However I have a few questions.

First at cli if I issue the show vlans command it returns No Virtual LANs configured. If I check through CCP I see them.. Why is that I can't see them via the show vlans command?

Second I have two random random interfaces called NVI0 Null0. NVI0 is shown at cli but it doesn't shown through the CCP. The other interface Null0 is shown through the CCP but not through the cli. What are those two interfaces and their purposes? I believe NVI0 is a virtual NAT interface, but I couldn't be sure and I didn't understand the purpose. The Null0 interface I believe is used to prevent routing loops when you run a routing protocol but I have yet to issue or deploy EIGRP, RIP, or other.

Third how do I disable CCP-Exp so it won't run through a web browser? I am using the CCP not the CCP Exp and I don't want the CCP EXP to be accessible. Can I just delete the file or file(s) from flash and accomplish what I want?

-#- --length-- -----date/time------ path
1     28461436 Mar 01 1984 00:01:00 c880data-universalk9-mz.150-1.M4.bin
2         3331 Feb 05 2011 17:19:36 cpconfig-8xx.cfg
3      2941440 Feb 05 2011 17:19:54 cpexpress.tar
4         1038 Feb 05 2011 17:20:04 home.shtml
5       115712 Feb 05 2011 17:20:12 home.tar
6      1697952 Feb 05 2011 17:20:30 securedesktop-ios-3.1.1.45-k9.pkg
7       415956 Feb 05 2011 17:20:42 sslclient-win-1.1.4.176.pkg
8          720 Feb 27 2011 06:29:06 vlan.dat

And last I want to backup my IOS. I'm confused as to which file is my IOS. c880data-universalk9-mz.150-1.M4.bin looks like it by the size, but I couldn't understand what securedesktop-ios-3.1.1.45-k9.pkg was. Also when I checked out the current IOS releases they are at version 12.4 or about, so how is it my router runs a version 15 IOS?

[Reza Sharifi · Accepted solution]

Hi Joe,

Since I don't know what CCP and CCP-Exp is, I only answer your last question.

c880data-universalk9-mz.150-1.M4.bin is your current IOS you are running and you should be able to see the same name if you issue command "sh ver"

You can use TFTP to back up your IOS.

Also, Cisco directly went from IOS 12 to 15.  There is no IOS !3 and 14, so you are running the latest main line image

HTH

Reza

[Joe Conklin]

Thats helpful for the last question, thanks. I'll still need help with the others if anyone can answer those.

The CCP is the Cisco Configuration Professional. It is the replacement for the Security Device Manager. The CCP Express is a very scalled down version of the Cisco Configuration Profession which is basically the equivalent of a Linksys web gui for an IOS router. It is pitiful. Hence I want to remove access to it, and don't plan on using it.

[cadet alain · Accepted solution]

Hi,

To see the VLANS on a router with a switch module you must issue sh sw-vlan command.

You can delete CCP express without any problem.

The NVI is indeed created when you issue nat command on interface and for Null0 just do a sh run to see if it is in the running

and if not post the screenshot where you this interface.

Regards.

Alain.

[Joe Conklin]

show sw-vlans doesn't work, and in fact on the Cisco 881 Router below are the show commands available that begin with the letter S

fw881#show s?
sampler         sasl            scp            sctp
secure          sessions        smf            snapshot
snmp              sntp            sockets        spanning-tree
ssh                 ssm             sss            stacks
standby           startup-config  storm-control  subscriber
subscriber-policy  subsys

Below is where I see Null0 in my running config but I still don't understand where it came from or what its being used for on my router.

interface Null0
no ip unreachables

[cadet alain · Accepted solution]

Hi,

Sorry I did a typo for the command , this is sh vlan-switch and not what I told you before.

For Null0, I don't see why CCP put it here if it doesn't appear in the routing table.

Regards.

Alain.

[Bekzod Fakhriddinov]

hi Joe . have u ever such issue on 881 : the device behind of SVI can not reach outside devices although there are routing tables ?