MacBook Pro runs very slow when on battery

A colleague gave me a 2010 MacBook Pro and I notice that it runs very slow when running on battery. Boot-up takes a very long time and everything is lagging. It is practically unusable. When the power supply is plugged in however, it works normally. I tried the usual prescribed troubleshooting from Apple to reset the SMC but that still didn’t fix the issue.

Finally I came across this discussion on Apple Support Communities. The root cause seems to be faulty temperature sensor damaged by liquid spill. Because the sensor is faulty, macOS assumes the system is overheating and drops the CPU cycle which in turns makes everything runs much slower. Read More

Setup port channel between a pair of Cisco ASA and a switch stack

For better redundancy, we may want to use port channel to connect a highly available active/passive pair of Cisco ASA to a switch stack. An important aspect to know is to create separate port channels on the switch stack, one for each ASA. On each ASA, it is still a single port channel because the configuration is replicated between the units. If you group all interfaces on the switch stack into a single port channel connecting to both ASA, the port channel will not be established because of the separate ASA system IDs. A single port channel is also not desirable because you do not want traffic to be sent to the standby ASA. Read More

Cisco ASA – A group cannot contain services of different types

In Cisco ASA 6.4.9 – and older possibly – it is possible to mix different types of service in a group. So you can have TCP and UDP or TCP-UDP and TCP in the same group.

Later versions of ASA do not allow this. In ASDM, you will get error message like below if you attempt to do this.

Additionally, if you had created a group with mixed types of service, later version of ASDM will not show this service group.