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Flow Control sending pause frames, ASA still getting overrun errors

As the title says, a switch is receiving pause frames, but the ASA is still getting overrun errors.  We have played with the settings for flowcontrol, but nothing seems to stop these errors.  I have performed troubleshooting as per this document:


There does not seem to be any significant resource hogs, Is there a misconfiguration on one of the devices?  I am trying to find out what will fix the overrun issue.  What else should I try?


Console output of the two connected interfaces:

*ASA 5525x* - Version ASA 9.4(2)11

ASA1# sho int gi 0/1
Interface GigabitEthernet0/1 "Inside", is up, line protocol is up
Hardware is i82574L rev00, BW 1000 Mbps, DLY 10 usec
Auto-Duplex(Full-duplex), Auto-Speed(1000 Mbps)
Input flow control is unsupported, output flow control is on
MAC address 0078.8847.87f3, MTU 1500
IP address, subnet mask
96959814285 packets input, 20072810163568 bytes, 0 no buffer
Received 279155 broadcasts, 0 runts, 0 giants
3967982 input errors, 0 CRC, 0 frame, 3967982 overrun, 0 ignored, 0 abort
0 pause input, 0 resume input
0 L2 decode drops
195761529692 packets output, 228626395757828 bytes, 424459 underruns
1611 pause output, 339 resume output
0 output errors, 0 collisions, 20 interface resets
0 late collisions, 0 deferred
511 input reset drops, 79 output reset drops
input queue (blocks free curr/low): hardware (496/362)
output queue (blocks free curr/low): hardware (468/0)
Traffic Statistics for "Inside":
96955623491 packets input, 18217124488226 bytes
195761954647 packets output, 225071328596014 bytes
168532556 packets dropped
1 minute input rate 18647 pkts/sec, 3674933 bytes/sec
1 minute output rate 39880 pkts/sec, 45959787 bytes/sec
1 minute drop rate, 39 pkts/sec
5 minute input rate 17684 pkts/sec, 3429228 bytes/sec
5 minute output rate 46221 pkts/sec, 54987848 bytes/sec
5 minute drop rate, 32 pkts/sec
ASA1# sho run int gi 0/1
interface GigabitEthernet0/1
flowcontrol send on 16 20 26624
nameif Inside
security-level 100
ip address


*C6824-X-LE-40G* - Version 15.2(02)SY [Rel 1.0]

C6824#sho int te 1/1/24
TenGigabitEthernet1/1/24 is up, line protocol is up (connected)
Hardware is C6k 10000Mb 802.3, address is 706b.b99a.b988 (bia 706b.b99a.b988)
Description: TO_ASA
MTU 1500 bytes, BW 1000000 Kbit/sec, DLY 10 usec,
reliability 255/255, txload 7/255, rxload 99/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Full-duplex, 1000Mb/s, media type is 10/100/1000BaseT
input flow-control is on, output flow-control is off
Clock mode is auto
ARP type: ARPA, ARP Timeout 04:00:00
Last input never, output never, output hang never
Last clearing of "show interface" counters never
Input queue: 0/2000/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: fifo
Output queue: 0/40 (size/max)
5 minute input rate 390797000 bits/sec, 41416 packets/sec
5 minute output rate 30701000 bits/sec, 17646 packets/sec
134005935676 packets input, 154259099562516 bytes, 0 no buffer
Received 412337 broadcasts (409808 multicasts)
1 runts, 0 giants, 0 throttles
1 input errors, 1 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog, 0 multicast, 1950 pause input
0 input packets with dribble condition detected
64911682697 packets output, 16586145887747 bytes, 0 underruns
0 output errors, 0 collisions, 3 interface resets
0 unknown protocol drops
0 babbles, 0 late collision, 0 deferred
0 lost carrier, 0 no carrier, 0 pause output
0 output buffer failures, 0 output buffers swapped out
C6824#sho run int te 1/1/24
Building configuration...

Current configuration : 191 bytes
interface TenGigabitEthernet1/1/24
description TO_ASA
switchport mode access
switchport access vlan 998
flowcontrol receive on
spanning-tree portfast edge




VIP Mentor

Re: Flow Control sending pause frames, ASA still getting overrun errors



on the ASA GigabitEthernet0/1 interface, set the duplex setting to 'full' manually instead of leaving it at the default auto. Also, try some other value, e,g. 'flowcontrol send on 95 200 10000'  (this value is from the Cisco doc for 9.4.).

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