I live in a home , and we have a router and 3 computers are connected to it.
Now i want to add this network to the trusted zone , but what if for example my brother stumbles upon a worm on his computer , will the comodo firewall still stop the worm entering MY computer ?
Not true. When the network is trusted you won’t be asked.
Trusting the local network increases risk to some extend. When the worm would exploit a zero day security breach and if the buffer overflow detection of D+ does not see the BO (it does not detect all of them) you will get infected.
Why do you want to make your local network shared? Do you want to share files between your and your brother’s computer?