Cisco 2901 LAN Interface "shuts down" intemitently

[onyangoliech]

I recently installed a cisco 2901 router. The router is connected to hosts using a SG 200-50 50-Port Gigabit Smart Switch

Problem is the router internal interface keeps shutting down without notice and randomly. At that time I cannot ping the interrface from a LAN PC even though I can ping other hosts on the LAN. The ISP link is okay since I can put a static IP on my computer and access the net.

[mfurnival]

Can you provide the output of the logging buffer from the router and / or the switch?

[Richard Burts]

When this problem occurs do you have console access to the router? If so it would be very helpful if you would provide some outputs taken while the problem is happening. These would include the outputs of show ip interface brief and the output of show arp.

When the problem happens does it impact all PCs connected through the switch or does it affect some PCs? It might also be helpful if you would post the configuration of the router and perhaps of the switch.

HTH

Rick

[bendatcrox]

Morning,
On the SG200 side are you using smartport? If you are don't.

I have had significant problems with IOS based devices plugged into SB series switching. Either disable smartports altogether or set the port type to "other" on the SG200 side.

Sent from Cisco Technical Support iPhone App

[johnlloyd_13]

hi,

do you see any duplicate IP errors (same with LAN GW) in 'show log'?

[onyangoliech]

Thanks for the response guys, sorry I did not have access to the router. I do have a console connection to the router. sh ip int b shows that all interfaces are up, both status and Protocol. The only one that is administratively down is the Embedded-Service-Engine 0/0

I will capture the 'show log' output the next time it's down. I came this morning only to find it up again having left it down last week.

[onyangoliech]

These are the router logs I got from last nights shutdown...any clues coz I can't see anything wrong

ROUTER#sh log

Syslog logging: enabled (0 messages dropped, 2 messages rate-limited, 0 flushes, 0 overruns, xml disabled, filtering disabled)

No Active Message Discriminator.

No Inactive Message Discriminator.

    Console logging: level debugging, 15 messages logged, xml disabled,

                     filtering disabled

    Monitor logging: level debugging, 0 messages logged, xml disabled,

                     filtering disabled

    Buffer logging:  level debugging, 15 messages logged, xml disabled,

                    filtering disabled

    Exception Logging: size (4096 bytes)

    Count and timestamp logging messages: disabled

    Persistent logging: disabled

    Trap logging: level informational, 18 message lines logged

        Logging Source-Interface:       VRF Name:

Log Buffer (8192 bytes):

Jan  2 12:00:04.527: %IOS_LICENSE_IMAGE_APPLICATION-6-LICENSE_LEVEL: Module name = c2900 Next reboot level = ipbasek9 and License = ipbasek9

Jun 11 08:42:48.619: %IFMGR-7-NO_IFINDEX_FILE: Unable to open nvram:/ifIndex-table No such file or directory

Jun 11 08:42:59.275: %LINK-3-UPDOWN: Interface GigabitEthernet0/0, changed state to up

Jun 11 08:42:59.275: %LINK-3-UPDOWN: Interface GigabitEthernet0/1, changed state to up

Jun 11 08:43:00.439: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/0, changed state to up

Jun 11 08:43:00.439: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/1, changed state to up

Jun 11 08:43:02.479: %LINEPROTO-5-UPDOWN: Line protocol on Interface Tunnel1, changed state to down

Jun 11 08:43:02.479: %LINEPROTO-5-UPDOWN: Line protocol on Interface NVI0, changed state to up

Jun 11 08:43:03.511: %LINK-5-CHANGED: Interface Embedded-Service-Engine0/0, changed state to administratively down

Jun 11 08:43:04.511: %LINEPROTO-5-UPDOWN: Line protocol on Interface Embedded-Service-Engine0/0, changed state to down

Jun 11 08:43:07.419: %SYS-5-CONFIG_I: Configured from memory by console

Jun 11 08:43:10.575: %SYS-5-RESTART: System restarted --

Cisco IOS Software, C2900 Software (C2900-UNIVERSALK9-M), Version 15.1(4)M4, RELEASE SOFTWARE (fc1)

Technical Support: http://www.cisco.com/techsupport

Copyright (c) 1986-2012 by Cisco Systems, Inc.

Compiled Tue 20-Mar-12 18:57 by prod_rel_team

Jun 11 08:43:10.663: %SSH-5-ENABLED: SSH 1.99 has been enabled

Jun 11 08:43:10.767: %SNMP-5-COLDSTART: SNMP agent on host AUSTCO-MELB is undergoing a cold start

Jun 11 08:43:11.387: %LINEPROTO-5-UPDOWN: Line protocol on Interface Tunnel1, changed state to up

ROUTER#sh ip int b

Interface                  IP-Address      OK? Method Status                Protocol

Embedded-Service-Engine0/0 unassigned      YES NVRAM  administratively down down

GigabitEthernet0/0         192.168.0.1     YES NVRAM  up                    up

GigabitEthernet0/1         "external ip address"  YES NVRAM  up                    up

NVI0                       192.168.0.1     YES unset  up                    up

Tunnel1                    172.16.1.1      YES NVRAM  up                    up

ROUTER#ping "external ip address"

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to "external ip address", timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 1/3/4 ms

ROUTER#ping 192.168.0.1

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 192.168.0.1, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/1 ms

ROUTER#ping 192.168.0.5

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 192.168.0.5, timeout is 2 seconds:

.....

Success rate is 0 percent (0/5)

ROUTER#ping 192.168.0.100

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 192.168.0.100, timeout is 2 seconds:

.....

Success rate is 0 percent (0/5)

ROUTER#ping 192.168.0.110

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 192.168.0.110, timeout is 2 seconds:

.....

Success rate is 0 percent (0/5)

ROUTER#ping 192.168.0.150

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 192.168.0.150, timeout is 2 seconds:

.....

Success rate is 0 percent (0/5)

ROUTER#ping 192.168.0.240

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 192.168.0.240, timeout is 2 seconds:

.....

Success rate is 0 percent (0/5)

ROUTER#

[Richard Burts]

Thanks for the outputs. They are helpful, though I think they are not enough for us to identify the issue yet. I notice a couple of things in the logs, though I am not sure that either necessarily point to the problem.

- the logs indicate that the router just rebooted. Do we know what caused the reboot?

- We see this address on the Gig interface which is expected

GigabitEthernet0/0         192.168.0.1     YES NVRAM  up                    up

and we see that address also on this interface

NVI0                       192.168.0.1     YES unset  up                    up

So I am a bit curious about what is going on with NVI0? Can you tell us anything? Or post parts of the config?

I had asked for the output of show arp on the router when the problem was happening. I suspect that I can predict what we would see, but it might be helpful if you could get us that output the next time that the problem happens.

It might also be helpful if you can tell us how you re-establish connectivity. When the problem happens and you do not have connectivity between the router and the LAN what do you do to get things working again?

This reminds me a bit of an experience that I had at a customer site. We had a Cisco device connected to a non Cisco device which connected to a LAN. We found that when the Cisco reloaded or rebooted that we lost connectivity through the non Cisco device. We determined that there is some incompatibility with that device such that every time the Cisco rebooted the other device stopped talking to us. We would have to shut/no shut or disconnect/connect the interface and then things would go back to normal. I wonder if this could be the situation in your problem?

HTH

Rick

[onyangoliech]

Thanks Richard I'll print out the arp table when it goes down next. I read that the NVI0 is used for routers where NAT is not used. I have NAT on my router and if turning it off will help I don't mind doing that. I have never used the interface before anyway.

I restarted the router after downloading the log but still the Interface did not come up. I then restarted the switch and the connection was restored. As I indicated in the initial post it's a SG 200-50 50-Port Gigabit Smart Switch. I'm planning to take the router down the whole night today and do a continuous ping and pipe the output to a file...just to rule out the possibility that another machine is taking over the router ip address.