Firewall conflict with Multibit wallet

[HeroCat]

Is that possible that firewall conflict with Multibit wallet, in result you loose BTC. May be not all firewalls, just some of them. What you guys think ? This is important question - you can loose BTC.

[shorena]

Unless you talk about malware infected "personal" firewall. No.

And in the above case its not the firewall, but the malware.

[jim618]

If you have port 8333 closed via a firewall MultiBit won't be able to reach the Bitcoin network and be able to sync.

This would also mean you couldn't send bitcoin.

As long as you have access to your private keys (and no-one else does) you wouldn't lose your bitcoin though.

[allgoodthings1]

Just to clarify, port 8333 is not closed by default on most (if any!) firewall with respect to outbound traffic. So -- unless by some fluke, your router has arbitrarily closed port 8333 for ALL traffic (outbound and inbound) -- you can perfectly run any bitcoin software (including Multibit) without opening the port on your router.

The only time you need to open the port is for inbound traffic, and that's only if you're running Bitcoin Core, bitcoind or btcd -- the full blockchain programs -- and want to make your copy of the blockchain available for others to reach and use for verification. This is often referred to as running a full node.