Update zyxel USG FLEX 100 (4.55 to 5.21)

Wassim

Hello everyone,

I have a zyxel USG FLEX 100 and I need to update it. However, it is in version 4.55 and I would like to upgrade it to 5.21. Normally, I would have to go through intermediate versions but these are not available since the ftp has been closed.

Do you have a link to get the old versions of this firmware or should I update directly to 5.21? In the last case, I would have to do a reset and then restore my configuration?

PeterUK

You can get 5.10(ABUH.0)C0 here 
Download Library | ZyXEL

backup your config and try upgrading  

mMontana

I stand by @peteruk suggestion of backing up configuration.
Which means outside the device, at least 1 copy.
If something goes wrong, back to defaults then apply.

Zyxel_Emily

Hi @Wassim,

You can upgrade USG FLEX 100 from 4.55 to 5.21 directly. Before upgrading, remember to back up startup-config.conf of firmware 4.55. Then upload firmware 5.21 to standby firmware partition. More details can be found in this discussion. 

PeterUK

You can get 5.10(ABUH.0)C0 here 
Download Library | ZyXEL

backup your config and try upgrading  

mMontana

I stand by @peteruk suggestion of backing up configuration.
Which means outside the device, at least 1 copy.
If something goes wrong, back to defaults then apply.

Zyxel_Emily

Hi @Wassim,

You can upgrade USG FLEX 100 from 4.55 to 5.21 directly. Before upgrading, remember to back up startup-config.conf of firmware 4.55. Then upload firmware 5.21 to standby firmware partition. More details can be found in this discussion.