[c-nsp] 1700-series router falls off the Ethernet

Thu Aug 25 02:52:42 EDT 2005

I have had a similar problem a few months ago. I believe it was between a
Cat 2900XL (me) and a Nortel switch (customer) - the Ethernet would go down
after a few hours of operation.

We fixed it by adjusting the duplex and speed settings on both sides until
we found a combination that would work without creating any errors.

YMMV

Vincent

> -----Original Message-----
> From: cisco-nsp-bounces at puck.nether.net [mailto:cisco-nsp-
> bounces at puck.nether.net] On Behalf Of Ed Ravin
> Sent: mercredi 24 août 2005 21:59
> To: Adam Maloney
> Cc: tkern at CHARMER.COM; cisco-nsp at puck.nether.net
> Subject: [c-nsp] 1700-series router falls off the Ethernet
> 
> The story so far - a few users with Cisco 1700-series routers
> have reported that every now and then (once or twice a month?)
> the router stops receiving Ethernet packets on FastEthernet0.
> 
> It just hit me again: as usual, "clear interface faste0" fixed it.
> I ran a few "show int" commands, but forgot to do "show controller" as
> suggested below.
> 
> Here's what I saw with "show int faste0":
> 
>   MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,
>      reliability 255/255, txload 1/255, rxload 1/255
>   Encapsulation ARPA, loopback not set
>   Keepalive set (10 sec)
>   Full-duplex, 100Mb/s, 100BaseTX/FX
>   ARP type: ARPA, ARP Timeout 04:00:00
>   Last input 00:06:47, output 00:00:00, output hang never
>   Last clearing of "show interface" counters never
>   Input queue: 0/75/148038/0 (size/max/drops/flushes); Total output drops:
> 0
>   Queueing strategy: fifo
>   Output queue :0/40 (size/max)
>   30 second input rate 0 bits/sec, 0 packets/sec
>   30 second output rate 0 bits/sec, 0 packets/sec
>      610775024 packets input, 1948694396 bytes
>      Received 87789888 broadcasts, 0 runts, 0 giants, 0 throttles
>      38153 input errors, 0 CRC, 0 frame, 38153 overrun, 0 ignored
>      0 watchdog
>      0 input packets with dribble condition detected
>      433012508 packets output, 3503679533 bytes, 135000 underruns
>      135000 output errors, 0 collisions, 8 interface resets
>      0 babbles, 0 late collision, 0 deferred
>      0 lost carrier, 0 no carrier
>      0 output buffer failures, 0 output buffers swapped out
> 
> And when I ran "show int" a second time around 15 seconds later:
> 
>   MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,
>      reliability 255/255, txload 1/255, rxload 1/255
>   Encapsulation ARPA, loopback not set
>   Keepalive set (10 sec)
>   Full-duplex, 100Mb/s, 100BaseTX/FX
>   ARP type: ARPA, ARP Timeout 04:00:00
>   Last input 00:07:02, output 00:00:05, output hang never
>   Last clearing of "show interface" counters never
>   Input queue: 0/75/148038/0 (size/max/drops/flushes); Total output drops:
> 0
>   Queueing strategy: fifo
>   Output queue :0/40 (size/max)
>   30 second input rate 0 bits/sec, 0 packets/sec
>   30 second output rate 0 bits/sec, 0 packets/sec
>      610775024 packets input, 1948694396 bytes
>      Received 87789888 broadcasts, 0 runts, 0 giants, 0 throttles
>      38153 input errors, 0 CRC, 0 frame, 38153 overrun, 0 ignored
>      0 watchdog
>      0 input packets with dribble condition detected
>      433012511 packets output, 3503679789 bytes, 135000 underruns
>      135000 output errors, 0 collisions, 8 interface resets
>      0 babbles, 0 late collision, 0 deferred
>      0 lost carrier, 0 no carrier
>      0 output buffer failures, 0 output buffers swapped out
> 
> Notice that input queue, errors, and input packets are all frozen,
> while output packets seem to still be going out (3 packets totaling
> 256 bytes - other than that and the last input time, none of the
> numbers changed).
> 
> I was pinging the router during the interval between the two "show
> int" commands, just to make sure there was input traffic.
> 
> Any ideas?  This is clearly a bug, since I'm not the only one getting
> it, and it's not limited to any one router.  I've already swapped out
> the router, the cable, and upgraded the IOS at least once.
> 
> 	-- Ed
> 
> On Thu, May 05, 2005 at 01:47:16PM -0500, Adam Maloney wrote:
> > On Thu, 5 May 2005, Kern, Tom wrote:
> > > I have a 1700 router which is my internet router. it has a frame-relay
> > > serial int and an etherent int.  About twice a month, the ethernet
> > > int dies. Actually, it says eth0 up, line protocol up but i can't
> > > connect to the internal network from the router. I can
> > > however ping out on the frame.
> ...
> >
> > > well, the router says nothing. I was wondering what I should turn on
> to
> > > make it more verbose.
> >
> > Get some show int eth0 and show controller eth0 output (twice, a few
> > seconds apart).  Look at the interface queues and "last input" timers.
> > Check if these or the packet counters or error counters are increasing
> > between the two times you get the output.
> >
> > Check bugtool and see if this is a known bug for your IOS version.
> There
> > have been bugs in the past where an interface input queue will wedge
> under
> > certain conditions.
> >
> > I would also try unplugging the ethernet cable from the cisco, waiting a
> > few secs, and then plugging it back in to see if that bounces the
> > interface hardware.
> >
> > You might also try putting a cheap hub or switch between the cisco and
> the
> > firebox, and see if that makes any difference.
> >
> > > Rebooting the firebox doesn't help. only reloading the router clears
> the
> > > issue
> >
> > I assume you did a shut/no shut on the interface before reloading?
> > _______________________________________________
> _______________________________________________
> cisco-nsp mailing list  cisco-nsp at puck.nether.net
> https://puck.nether.net/mailman/listinfo/cisco-nsp
> archive at http://puck.nether.net/pipermail/cisco-nsp/