I always found it odd that I couldn’t negate terminal commands in IOS like other commands.
Eg; no Terminal Monitor
I just assumed it wasn’t there, until I saw another engineer execute to disable term mon.
Router# terminal no monitor
It seems in IOS the terminal commands are special in that they require the terminal key word before the no keyword to negate sub-commands.
It is possible to use 3rd party SFP’s in a Cisco 3750 with the following commands:
Switch(config)#no errdisable detect cause gbic-invalid
The first command will generate the following warning from cisco :
” Warning: When Cisco determines that a fault or defect can be traced to
the use of third-party transceivers installed by a customer or reseller,
then, at Cisco’s discretion, Cisco may withhold support under warranty or
a Cisco support program. In the course of providing support for a Cisco
networking product Cisco may require that the end user install Cisco
transceivers if Cisco determines that removing third-party parts will
assist Cisco in diagnosing the cause of a support issue.”
I wouldn’t recommend using non-Cisco SFP’s in production environments, but for a lab save the bucks and go for it.
I discovered a really cool feature of IOS that is probably common knowledge but I was never aware of.
You can perform a ping sweep of a directly connected network by pinging the broadcast or Network address.
The output is as follows :
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.1.255, timeout is 2 sec
Reply to request 0 from 192.168.1.19, 4 ms
Reply to request 0 from 192.168.1.59, 40 ms
Reply to request 0 from 192.168.1.57, 40 ms
Reply to request 0 from 192.168.1.56, 40 ms
This is incredibly useful for doing discovery and populating the routers ARP table after a reboot.