Switchport was running with reduced speed of 100 Mbps instead of 1000 Mbps

[Alpha9827]

The switchport (to which one of the physical NIC of ESXi Server is connected) was running with reduced speed of 100 Mbps instead of 1000 Mbps, although the speed was set to auto at both end. There was no error or speed-duplex mismatch alert on the switchport. Issue resolved after the switchport was bounced.

- Is any other alert gets generated automatically when the switchport negotiates at a lower speed?

- If not, is there any configuration to generate this kind of alert on its own?

Running on Catalyst 4500 L3 Switch Software (cat4500e-UNIVERSALK9-M), Version 03.08.06.E RELEASE SOFTWARE (fc4)

!
interface GigabitEthernet1/6/24
description ## XXXXXXXXXXXXXXXXXXXXXXXXXXX #
switchport access vlan 4
switchport mode access
switchport priority extend trust
auto qos trust
storm-control broadcast level 15.00
qos trust extend
spanning-tree portfast edge
spanning-tree guard root
service-policy input AutoQos-4.0-Input-Policy
service-policy output AutoQos-4.0-Output-Policy
end

[balaji.bandi]

try below commands on the switch

speed 1000

speed nonegotiate

if still now working

can you post-show interface g x/x 

[Alpha9827]

From VMware side it was suggested to use auto negotiation as a standard practice.

XXXXXXXXX#sh int Gi1/6/24
GigabitEthernet1/6/24 is up, line protocol is up (connected)
Hardware is Gigabit Ethernet Port, address is 0462.7344.5d97 (bia 0462.7344.5d97)
Description: ## XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX $#
MTU 1500 bytes, BW 1000000 Kbit/sec, DLY 10 usec,
reliability 255/255, txload 1/255, rxload 7/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Full-duplex, 1000Mb/s, link type is auto, media type is 10/100/1000-TX
input flow-control is on, output flow-control is on
Auto-MDIX on (operational: on)
ARP type: ARPA, ARP Timeout 04:00:00
Last input never, output never, output hang never
Last clearing of "show interface" counters 3w0d
Input queue: 0/2000/0/0 (size/max/drops/flushes); Total output drops: 512928
Queueing strategy: Class-based queueing
Output queue: 0/40 (size/max)
5 minute input rate 29325000 bits/sec, 2982 packets/sec
5 minute output rate 3765000 bits/sec, 1337 packets/sec
3249254212 packets input, 4292784185479 bytes, 0 no buffer
Received 57433 broadcasts (1479 multicasts)
0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 input packets with dribble condition detected
1400191099 packets output, 712991715204 bytes, 0 underruns
0 output errors, 0 collisions, 1 interface resets
0 unknown protocol drops
0 babbles, 0 late collision, 0 deferred
0 lost carrier, 0 no carrier
0 output buffer failures, 0 output buffers swapped out

[Georg Pauwen]

Hello,

you could run the EEM script below. The script will run every 60 seconds (you can change that interval) and check if the interface runs at auto/100, if that is the case, a syslog message will be generated, and the interface will be bounced:

event manager applet INTERFACE_SPEED
event timer watchdog time 60
action 1.0 cli command "enable"
action 2.0 cli command "show interfaces status | inc Gi1/6/24"
action 3.0 string match "*a-100*" "$_cli_result"
action 4.0 if $_string_result eq "1"
action 5.0 syslog msg "Interface speed of GigabitEthernet1/6/24 has changed to a-100"
action 6.0 cli command "conf t"
action 7.0 cli command "interface GigabitEthernet1/6/24"
action 8.0 cli command "no shut"
action 9.0 end

[Deepak Kumar]

@Georg Pauwen  I think you missed "Shut" command in the EEM

[Georg Pauwen]

Good catch ! You are absolutely right. So the script would look like this:

event manager applet INTERFACE_SPEED
event timer watchdog time 60
action 1.0 cli command "enable"
action 2.0 cli command "show interfaces status | inc Gi1/6/24"
action 3.0 string match "*a-100*" "$_cli_result"
action 4.0 if $_string_result eq "1"
action 5.0 syslog msg "Interface speed of GigabitEthernet1/6/24 has changed to a-100"
action 6.0 cli command "conf t"
action 7.0 cli command "interface GigabitEthernet1/6/24"
action 8.0 cli command "shut"
action 9.0 cli command "no shut"
action 9.1 end