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6500 packet drop issues

Vladislav Vyakin
Beginner
Beginner

Hello

Im upgrade 6509 from sup720 to 2T. After upgrade I have some issues on network with packet drop.
new IOS Version 15.1(2)SY9

1) issue
About once a day, monitoring show about 100% CPU.

c6509_1#sh processes cpu sort 1 | exclude 0.00
CPU utilization for five seconds: 99%/41%; one minute: 72%; five minutes: 80%
PID Runtime(ms) Invoked uSecs 5Sec 1Min 5Min TTY Process
438 4391888 3299421 1331 43.59% 25.18% 26.48% 0 IP Input
188 1456760 4932453 295 2.71% 2.48% 2.62% 0 slcp process
377 1107176 125483 8823 4.00% 1.99% 1.84% 0 Lif stats hw rea
24 345556 3073253 112 1.91% 1.10% 1.12% 0 ARP Input
418 66472 743697 89 0.79% 0.37% 0.36% 0 Switch IP Host T
...

ssh go down and print 1 symbol per 1 minute. Configuration is possible only from console. Network go unstable, large amoun of packets lost.

After some research I found that restart of one vlan interface make network stable immediately.

c6509_1#sh processes cpu history
88888999999999999999999999999999999999999999999999999
7777722222999999999999999999999999999999999999999999999999
100 ************************************************
90 ************************************************
80 *****************************************************
70 *****************************************************
60 *****************************************************
50 *****************************************************
40 *****************************************************
30 *****************************************************
20 *****************************************************
10 **********************************************************
0....5....1....1....2....2....3....3....4....4....5....5....
0 5 0 5 0 5 0 5 0 5

Affected vlan have pretty simple config with only 2 secondary ip address

c6509_1#sh run int vlan 6
Building configuration...
Current configuration : 214 bytes
!
interface Vlan6
ip address 10.214.108.1 255.255.255.0 secondary
ip address 10.214.109.1 255.255.255.0 secondary
ip address 10.214.104.5 255.255.252.0
no ip redirects
load-interval 30
hold-queue 250 in
end

2) issue
on neighbors routers, connected to this switch I see large amount of overrun errors

c2921_2#sh int gi 0/0
GigabitEthernet0/0 is up, line protocol is up
...
Last clearing of "show interface" counters 05:26:16
Input queue: 13/1000/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: fifo
Output queue: 0/40 (size/max)
5 minute input rate 1997000 bits/sec, 3586 packets/sec
5 minute output rate 1729000 bits/sec, 3143 packets/sec
413256950 packets input, 3392353819 bytes, 0 no buffer
Received 2559639 broadcasts (68 IP multicasts)
0 runts, 0 giants, 0 throttles
163383393 input errors, 0 CRC, 0 frame, 163383393 overrun, 0 ignored

What could it be?

1 Reply 1

Reza Sharifi
Hall of Fame Expert Hall of Fame Expert
Hall of Fame Expert

Hi,

Does it stabilize if you remove "hold-queue 250 in" command?

HTH

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