negative buffer size

bberry · ‎10-11-2012

I am not sure if this question belongs here or in the WAAS catagory as I am running the router with WAAS express. I am figuring here since it revolves around the status of the buffers on the router.

I have a 2911 running WAAS Express connected to my AVPN network via a full T1 link. The location is always reporting slow response and I will admit there are times when the link is running close to the full T1 speed. But today I noticed that the size on the input queue is reporting a negative number. Could this be pointing toward an underlying issue that is creating this slowness? I have never noticed this before and I do not have it on other locations running the same platform. Any thoughts?? My interface config is listed at the bottom.

Serial0/0/0 is up, line protocol is up

Hardware is GT96K with integrated T1 CSU/DSU

Description: AT&T AVPN CKT#DHEC457563 T1 port

Internet address is 10.1.4.105/30

MTU 1500 bytes, BW 1544 Kbit/sec, DLY 20000 usec,

reliability 255/255, txload 19/255, rxload 207/255

Encapsulation PPP, LCP Open

Stopped: CDPCP

Open: IPCP, loopback not set

Keepalive set (10 sec)

Last input 00:00:00, output 00:00:00, output hang never

Last clearing of "show interface" counters 00:13:22

Input queue: -130107/75/0/0 (size/max/drops/flushes); Total output drops: 0

Queueing strategy: fifo

Output queue: 0/40 (size/max)

5 minute input rate 1257000 bits/sec, 134 packets/sec

5 minute output rate 121000 bits/sec, 86 packets/sec

118464 packets input, 129851700 bytes, 0 no buffer

Received 0 broadcasts (0 IP multicasts)

0 runts, 0 giants, 0 throttles

0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort

81978 packets output, 15226393 bytes, 0 underruns

0 output errors, 0 collisions, 0 interface resets

0 unknown protocol drops

0 output buffer failures, 0 output buffers swapped out

0 carrier transitions

DCD=up DSR=up DTR=up RTS=up CTS=up

interface Serial0/0/0

description AT&T AVPN CKT#DHEC457563 T1 port

bandwidth 1544

ip address 10.1.4.105 255.255.255.252

ip access-group 155 out

ip flow ingress

ip flow egress

ip virtual-reassembly in

ip virtual-reassembly out

encapsulation ppp

logging event subif-link-status

no peer neighbor-route

no fair-queue

service-module t1 timeslots 1-24

service-module t1 remote-alarm-enable

service-module t1 fdl both

waas enable interface Serial0/0/0
description AT&T AVPN CKT#DHEC457563 T1 port
bandwidth 1544
ip address 10.1.4.105 255.255.255.252
ip access-group 155 out
ip flow ingress
ip flow egress
ip virtual-reassembly in
ip virtual-reassembly out
encapsulation ppp
logging event subif-link-status
no peer neighbor-route
no fair-queue
service-module t1 timeslots 1-24
service-module t1 remote-alarm-enable
service-module t1 fdl both
waas enable

Raju Sekharan · ‎10-11-2012

Defintely hitting a bug

What is the code you are running ?

bberry · ‎10-11-2012

I am only seeing this at the one location. I have half a dozen or so other locations that are running the same version and on the ones I have checked so far are not displaying this issue.

hart_r uptime is 16 weeks, 2 days, 3 hours, 9 minutes

System returned to ROM by power-on

System restarted at 10:15:46 CDT Tue Jun 19 2012

System image file is "flash0:c2900-universalk9-mz.SPA.151-4.M1.bin"

Last reload type: Normal Reload

hart_r uptime is 16 weeks, 2 days, 3 hours, 9 minutes

System returned to ROM by power-on

System restarted at 10:15:46 CDT Tue Jun 19 2012

System image file is "flash0:c2900-universalk9-mz.SPA.151-4.M1.bin"

Last reload type: Normal Reload

Raju Sekharan · ‎10-12-2012

Look at this bug

CSCtl87463 -ve input queue size of interface on running traffic

Symptoms: Queue length becomes negative.

Conditions: The symptom is observed when Cisco IOS-WAAS is configured on the 
interface.

Workaround: There is no workaround.

Your code doesn't have fix for this

15.1(4)M3 has fix for this

Thanks

Raju

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bberry · ‎10-12-2012

rajs2,

Could this possibly affect overall through put in the router? I am running WAAS but like I said this is the only one that is displaying the negative numbers. It is also the one that has the highest utilization most of the time. All locations are usually running at the maximum 250 TCP connections.

Brent

Raju Sekharan · ‎10-12-2012

This will not have any impact on your traffic. it just shows wrong counters.

Thanks

Raju

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