I cannot find EOL information on M4600
@Norman The M4600 has not had an end of sale or end of life announced yet. The larger appliances tend to be supported for longer due to the hardware capabilities of those systems.
When it is eventually announced, it will be posted here:https://www.watchguard.com/wgrd-trust-center/end-of-life-policy
In general, most devices will have a 3 year gap between the end of sale (when they're placed on that page) and end of life.
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