Hi,

I have some routers to upgrade on:

v4.10
v5.2
v5.25
v6.10

Upgrading from v6.10 to current stable seems to be fine. When I click download upgrade on v5.25 it goes to v6.40.8, does this mean you should try upgrade straight to? Also anything significant break?

Thanks!

edit: I should also mention these are remote so im reluctant to just 'try' it.

OMG, naughty corner for you!

How far is remote?
Personally I would expect something to break no matter which way you do this. Either roll the dice on upgrading all in one hit or take smaller chunks at it from the download archive.
https://mikrotik.com/download/archive

My suggestion for upgrades:

1. export configuration to plain text using command /export verbose file=exported-config.rsc and copy file to management computer
2. first upgrade to latest release with same major version number (e.g. upgrade the 4.10 device to 4.17)
3. then upgrade it to lowest version with next major version number you can get (e.g. upgeade 4.17 to 5.7)
4. repeat steps #2 and #3 until you reach version 6.0
5. upgrade 6.0 device to 6.40
6. upgrade 6.40 device to 6.42
7. upgrade 6.42 device to latest long-term (6.44.5 as of today)
8. upgrade routerboot (/system routerboard upgrade) once in a while, possibly each time you upgrade ROS

Steps #5 and #6 are needed because major change regarding bridge functionality was introduced in 6.41 ... upgrade scripts were fixed in 6.42.

I'd be very hesitant to do the upgrades remotely as the chances of something going wrong are not neglectable. If "remote" is far from your residence, it would be wiser to plan site visit and do the upgrades on site. In that case I'd follow different upgrade path:

1. export configuration to plain text using command /export verbose file=exported-config.rsc and copy file to management computer
2. netinstall device to latest long-term
3. perform routerboot upgrade (/system routerboard upgrade)
4. configure stuff needed (use exported config from step #1 as a reminder) but use factory default configuration as a basis

Using factory default as a basis is specially important when it comes to firewall, latest ROS versions come with a very decent default rule set and would likely pose a major improvement over whatever it is done on the ancient ROS installations you're faced with. Which itself makes this upgrade path preferred over the first one ...