Table of Contents

Some Cisco CLI Commands a must to remember. So I am posting this here for my own reference

WLC How to Configure AP

Enable IP SLA features

license boot module c1900 technology-package datak9

Reset stats on IP SLA

“ip sla restart <ID>”

How To Force Your Cisco Switch To Use 3rd Party SFPs

Despite the error displayed, which leaves no hope for a solution, keep smiling as you're about to be given one.

There are two undocumented commands which can be used to force the Cisco Catalyst switch to enable the GBIC port and use the 3rd party SFP:

(config)# service unsupported-transceiver
(config)# no errdisable detect cause gbic-invalid

When entering the service unsupported-transceiver command, the switch will automatically throw a warning message as a last hope to prevent the usage of a 3rd party SFP.

The no errdisable detect cause gbic-invalid command will help ensure the GBIC port is not disabled when inserting an invalid GIBC.

Since the service unsupported-transceiver is undocumented, if you try searching for the command with the usual method (?), you won't find it:

The same applies for the no errdisable detect cause gbic-invalid command.

We tried both service unsupported-transceiver & no errdisable detect cause gbic-invalid commands on 2960G, 3560G, 3750G, 4507R and 4507R-E Catalyst switches and all accepted the commands without a problem. In fact if the Catalyst switch is running IOS 12.2(25)SE and above, the undocumented commands are available.

Show device mac

show interfaces | i (.* line protocol is )|(.* address is)

Display the current maximum throughput level configured on a Cisco router

show platform hardware throughput level

Check Flapping Ports

show logging | include LINEPROTO|changed state

show logging | include LINK-3-UPDOWN
show logging | include LINK-3-UPDOWN


show interfaces status err-disabled


show interfaces [interface] counters


show interfaces [interface] | include flapping

show interfaces [interface] | include Last input

For Aruba/HPE

show interfaces brief
show logging -r | include "Link state"

Verify Cable Health

test cable-diagnostics tdr interface Gi1/0/10

show cable-diagnostics tdr interface Gi1/0/10

Check for port errors

show interface GigabitEthernet1/0/1 | include line protocol|error|CRC|collis|drops

Check for STP ERRORS

sh logs

show spanning-tree inconsistentports

show spanning-tree blockedports

show spanning-tree detail | in ieee|from|occur|is exec