firmware upgrade and downgrade

Each partition maintains a separate config.

BIG-IPs have 3 "configuration sources"

• The "binary config" or "running config". This is held by MCPd and is what the actual TMM data-plane uses. Upon each boot, this config is read and used. This configuration can occasionally become corrupted.
• The "config files", bigip.conf, bigip_base.conf, profile_base.conf, and bigip.confs in partitions. These are read by MCPd and transformed into the "binary config" when you do a mcp reload and when you do "load sys config all".
• The REST configuration. This is held by restjavad and is used for iAppLX stuff (SSL Orchestrator, Access Guided Configuration, a few others)

The bigip.conf has a line at the top that has the version in plain text. This text prevents MCP from trying to load a config from the wrong version. You can remove this line and MCP will try to load it anyway.

F5 doesn't "support" (you can't open support cases on it) loading configs from older versions. However you can usually follow this procedure to make it work:

1- copy the confs to the partition.

2- load the config: tmsh load /sys config all

3- Edit the config file to remove or fix areas that cause errors

4- go to step 2