I recently could not figure it out for a while why my router has no network and ‘ping’ returns “operation not permitted” error. Turns out I missed single quite in firewall config:
config zone
option name 'wan'
list network 'wan'
list network 'wan4'
list network 'wan6he'
list network 'wan6p'
list network 'wan6te'
list network 'wan6r48'
list network 'wan4u
option input REJECT
option output ACCEPT
option forward REJECT
option masq 1
option mtu_fix 1
option masq6 0
It seems that you were directly editing the config files. I personally do the same and I accept the risks that I might make a typo that could 'break' things.
If you use LuCI (web interface) and/or UCI on the command line, things like quotes and the like will always be entered properly. This doesn't stop logical or some types of syntax issues (this is the price of a highly sophisticated and flexible environment), but it will prevent typos of this type from causing you grief.
Sure I can use uci or luci. Question is it expected behavior, blocked all network access, including local access to the router just because of a single quote typo? I can’t suggest a solution right now, just raising a question.
Just like a programming language or even regular written languages, a single typo can indeed cause unexpected results.
The config files are a series of instructions with defined syntax and formatting. When there are errors in the syntax/formatting, it can be difficult to predict the resulting behavior.
So while I wouldn't necessarily say that the specific thing you experienced is "expected behavior," I would say that it is "not unexpected." That is to say -- it's not that the system is designed to interpret this type of error and fail in a specific way, but rather that it's encountered an invalid config file that results in undefined behavior.
For future debugging: uci show network would like have announced the error for you.
Uci is rather strict with errors.
With most of the config files that is ok, and errors are rather harmless, but with the core services config files it can have effects, like you noticed.
There is the failsafe mode for recovering from this type of errors.
