Hone

Lessons · Network switches · upgrading the software

An upgrade, in the order the steps depend on each other

Check the space, copy the image, name it in a boot system line, save, then reload. Five steps, and the order is not a preference.

Hone is a place to practise programming. This is one of its lessons, written out in full and free to read without an account.

What it is for

Software upgrades are the job that goes wrong at 6am with the plant waiting. Every failure mode is one of these steps out of order or missing.

How to think about it

Do the four safe steps first and leave the reload until you are sure. And before you start: console access, and the old image still on the disk, so a failed boot is one line rather than a site visit.

Worked example

enable
The # prompt.
dir flash:
One. What is there, and how much room is left. The image is about 11 MB, so read the free figure.
copy tftp://192.168.7.4/c2960-lanbasek9-mz.152-2.E9.bin flash:
Two. The new image, onto the disk, beside the old one.
dir flash:
Both are there. The old one stays: it is the way back.
configure terminal
Three.
boot system flash:c2960-lanbasek9-mz.152-2.E9.bin
The box now knows which to load.
end
Out.
write memory
Four. Without this, the reload reads a startup configuration that has never heard of the new image.
show version
Still running the old one, and it will be until it restarts. That is the reload, and it is the only step that interrupts anything.

Your turn

Save, so the boot line survives the restart.

write 

The trap

Deleting the old image to make room and then discovering the new one does not boot. Delete it after the new version has come up and been checked, not before.

Practise upgrading the software on HoneA question on it now, a coding challenge where there is one, and it is remembered for review. Free, no email needed.