[nsp] Finding broadcast source

From: Blake Fithen (fithen@NetworksPlus.com)
Date: Fri Dec 29 2000 - 22:02:12 EST


Hi list, having trouble finding a source of what I believe
is a broadcast related problem. If I do a "debug atm error"
I get a ton of:

Dec 29 13:24:58.776 cst: ATM(ATM3/0): Encapsulation error1, link=7,
host=C7F0B537
Dec 29 13:24:58.968 cst: ATM(ATM3/0.6) Send:Error in encapsulation, No VC
for address 0x613DE328
Dec 29 13:24:58.968 cst: ATM(ATM3/0.6) Send:Error in encapsulation, No VC
for address 0x613DE328
Dec 29 13:24:58.968 cst: ATM(ATM3/0): Encapsulation error1, link=7,
host=C7F0B537
Dec 29 13:24:59.168 cst: ATM(ATM3/0.6) Send:Error in encapsulation, No VC
for address 0x613DE328
Dec 29 13:24:59.168 cst: ATM(ATM3/0.6) Send:Error in encapsulation, No VC
for address 0x613DE328
Dec 29 13:24:59.168 cst: ATM(ATM3/0): Encapsulation error1, link=7,
host=C7F0B537
Dec 29 13:24:59.368 cst: ATM(ATM3/0.6) Send:Error in encapsulation, No VC
for address 0x613DE328
Dec 29 13:24:59.368 cst: ATM(ATM3/0.6) Send:Error in encapsulation, No VC
for address 0x613DE328
Dec 29 13:24:59.368 cst: ATM(ATM3/0): Encapsulation error1, link=7,
host=C7F0B537
Dec 29 13:24:59.376 cst: ATM(ATM3/0.6) Send:Error in encapsulation, No VC
for address 0x613DE328

As you can see by the time stamp they are plentiful. Two Cisco
engineers are stumped. I've tried the recommendations at:

http://www.cisco.com/warp/public/121/debug_atm_err.html

to no avail. Tried to catch the IP address (0x613DE328 =
97.61.227.40) with host and network based filters. Tried
"debug ip packet [access-list #] but I can't catch anything.
The filter counters do not increase. If I ping the address
they increase. Ping fails, the address is defined nowhere
on our network, not in the routing table, and is a reserved
address according to ARIN. The CRC's on the physical
interface increase with the broadcasts IE:

  Encapsulation(s): AAL5
  4096 maximum active VCs, 81 current VCCs
  0 carrier transitions
  Last clearing of "show interface" counters 00:11:12
  Input queue: 0/75/4392 (size/max/drops); Total output drops: 413
  Queueing strategy: Per VC Queueing
  5 minute input rate 5040000 bits/sec, 1643 packets/sec
  5 minute output rate 2337000 bits/sec, 1616 packets/sec
     1083680 packets input, 411377591 bytes, 0 no buffer
     Received 1776 broadcasts, 0 runts, 0 giants, 0 throttles
     2554 input errors, 2554 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
     1069621 packets output, 194037151 bytes, 0 underruns

TELCO says circuit is clean. If I look at the individual VC's there
are CRC's increasing on only two VC's that are going to the same
location. All other VC's are very clean.

nwp-7206#sh atm vc 34
ATM3/0.6: VCD: 34, VPI: 10, VCI: 33
VBR-NRT, PeakRate: 1500, Average Rate: 500, Burst Cells: 1
AAL5-LLC/SNAP, etype:0x0, Flags: 0x20, VCmode: 0x0
OAM frequency: 0 second(s)
InARP DISABLED
Transmit priority 2
InPkts: 60248, OutPkts: 72273, InBytes: 8214927, OutBytes: 34713706
InPRoc: 193, OutPRoc: 599, Broadcasts: 0
InFast: 60055, OutFast: 71586, InAS: 0, OutAS: 0
InPktDrops: 0, OutPktDrops: 0
CrcErrors: 1869, SarTimeOuts: 0, OverSizedSDUs: 0
OAM cells received: 0
OAM cells sent: 0
Status: UP
nwp-7206#
nwp-7206#
nwp-7206#sh atm vc 36
ATM3/0.6: VCD: 36, VPI: 10, VCI: 34
VBR-NRT, PeakRate: 1500, Average Rate: 500, Burst Cells: 1
AAL5-LLC/SNAP, etype:0x0, Flags: 0x20, VCmode: 0x0
OAM frequency: 0 second(s)
InARP DISABLED
Transmit priority 2
InPkts: 128997, OutPkts: 110917, InBytes: 16306927, OutBytes: 36009889
InPRoc: 99, OutPRoc: 473, Broadcasts: 0
InFast: 128897, OutFast: 110241, InAS: 0, OutAS: 0
InPktDrops: 0, OutPktDrops: 0
CrcErrors: 1787, SarTimeOuts: 0, OverSizedSDUs: 0
OAM cells received: 0
OAM cells sent: 0
Status: UP
nwp-7206#
nwp-7206#

Any comments would be greatly appreciated.

Thanks, blake



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