Me and my brother want to play mods together. We play on LAN servers, but when we try to play we both have a connection error. How do we keep Minecraft from crashing?

So many different things could be going wrong here... The mod could be crashing, your network could be faulty, give me more info... What mods? What version of minecraft? What is your router brand name? What operating system does your computer run?

Hope I can help... Mod crashes are my worst enemy as well