5.3 not accepting connections - What I'm missing?

[Maximiliano Eschoyez]

Dear all,

I've recently moved from FreeBSD 4.8 to 5.3. After the upgrade, I
found that my computer doesn't accept outside connections anymore.

The problem is: I can't connect to my computer through different
services (FTP, Telnet, SSH, etc.) and also, I can't redirect X output
to my display. I've verified that the corresponding daemons are
running and that all the steps to X redirection are done, but nothing
happens. I'm not using a firewall.

Looking deeply into the problem, I've found that also my computer
doesn't reply to ping request. But changing the kernel variable
'net.inet.icmp.bmcastecho' it started to work. There is something I
have to change to accept connections that I didn't notice?

I think that this problem is related to security reasons, but I didn't
find how to open a little bit my computer.

Summarizing: from my computer, I can connect to any other machine, but
I can't do the opposite connections.

I hope someone could help me. Thanks in advance, 

-- 
   M at X