08-09-2007 06:24 AM - edited 03-03-2019 06:15 PM
I've got a Cisco 2611 router running an IP-only GD release of 12.2(40). 48MB RAM. I've got a 384K frame-relay port attached to a WIC card; the PVC is 192K. Pertinant parts of 'show interface' are below. Do you think I have a queue problem, or a wiring problem?
Input queue: 0/75/0/0 Total output drops: 96
54 input errors, 52 CRC, 1 frame, 0 overrun, 0 ignored, 1 abort
The interface never goes down on layer3 or layer2; it's always up, but these errors come in abound one every 5-6 seconds or so. Traffic might hit 100% of the PVC speed once every 12 hours, but it does *not* do it constantly.
08-09-2007 06:40 AM
What are you more concerned with here, the output drops or the input errors. The output drops are an indication of oversubscription, even if only for a millisecond. Since the default output queue is 40 packets, all it takes is a single burst of 41+ packets to fill this queue and have a drop, which wont show up on any monitoring tool. If you paste in your FR main/subinterface configuration I can let you know how to make your output queue bigger.
As for the input errors, this usually indicates a line problem. You can try doing loopback tests at different points in your network to narrow it down, or you can just ignore them if they dont have much of an impact. What kind of serial interface module are you using?
08-09-2007 06:59 AM
Here's the pertinant parts of my config:
_____________________________________________
rtr-TAGS1#show run
Building configuration...
Current configuration : 2753 bytes
!
version 12.2
service timestamps debug uptime
service timestamps log uptime
service password-encryption
!
hostname rtr-TAGS1
!
ip subnet-zero
!
no ip domain-lookup
!
ip multicast-routing
ip multicast cache-headers
multilink virtual-template 1
!
!
interface Ethernet0/0
ip address 192.168.147.1 255.255.255.0
ip pim dense-mode
ip cgmp
no ip mroute-cache
half-duplex
!
interface Ethernet0/1
ip address 192.168.149.1 255.255.255.0 secondary
ip address 192.168.150.5 255.255.255.252
ip pim dense-mode
no ip mroute-cache
half-duplex
!
interface Serial0/2
description Frame Relay to the Columbia DOC
no ip address
no ip proxy-arp
encapsulation frame-relay
no ip mroute-cache
no service-module t1 remote-loopback full
service-module t1 timeslots 1-6
frame-relay lmi-type cisco
!
interface Serial0/2.371 point-to-point
description frame-relay to Columbia subinterface
ip address 192.168.146.2 255.255.255.252
no ip proxy-arp
ip pim dense-mode
no ip mroute-cache
no cdp enable
frame-relay interface-dlci 371 CISCO
!
rtr-TAGS1#show int s0/2
Serial0/2 is up, line protocol is up
Hardware is PQUICC with Fractional T1 CSU/DSU
Description: Frame Relay to the Columbia DOC
MTU 1500 bytes, BW 384 Kbit, DLY 20000 usec,
reliability 255/255, txload 18/255, rxload 7/255
Encapsulation FRAME-RELAY, loopback not set
Keepalive set (10 sec)
LMI enq sent 361, LMI stat recvd 361, LMI upd recvd 0, DTE LMI up
LMI enq recvd 0, LMI stat sent 0, LMI upd sent 0
LMI DLCI 1023 LMI type is CISCO frame relay DTE
Broadcast queue 0/64, broadcasts sent/dropped 122/0, interface broadcasts 59357
Last input 00:00:06, output 00:00:00, output hang never
Last clearing of "show interface" counters 01:00:14
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 96
Queueing strategy: weighted fair
Output queue: 0/1000/64/96 (size/max total/threshold/drops)
Conversations 0/6/256 (active/max active/max total)
Reserved Conversations 0/0 (allocated/max allocated)
Available Bandwidth 288 kilobits/sec
5 minute input rate 12000 bits/sec, 13 packets/sec
5 minute output rate 28000 bits/sec, 26 packets/sec
62944 packets input, 7651894 bytes, 0 no buffer
Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
143 input errors, 137 CRC, 5 frame, 0 overrun, 0 ignored, 1 abort
140261 packets output, 21092377 bytes, 0 underruns
0 output errors, 0 collisions, 0 interface resets
0 output buffer failures, 0 output buffers swapped out
0 carrier transitions
DCD=up DSR=up DTR=up RTS=up CTS=up
!
SHow interface switching:
!
Serial0/2 Frame Relay to the Columbia DOC
Throttle count 0
Drops RP 0 SP 0
SPD Flushes Fast 0 SSE 0
SPD Aggress Fast 0
SPD Priority Inputs 487 Drops 0
Protocol Path Pkts In Chars In Pkts Out Chars Out
Other Process 0 0 6115 79495
Cache misses 0
Fast 0 0 0 0
Auton/SSE 0 0 0 0
IP Process 3649 247900 812869 129102133
Cache misses 1465
Fast 963444 130889574 1176117 191863603
Auton/SSE 0 0 0 0
08-10-2007 06:24 AM
Original poster here -- Another interesting test I did proved that even when I'm experiencing CRC errors, I don't drop any packets. I tried pinging with 36-byte packets, and 1400-byte packets, and everything arrives OK with no drops. Does this further implicate a queueing problem?
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