Gmod Forces Friend to Download Addons He Already Has

My friend and I are trying to run a Hamachi server, enabling some addons that we both have. However, every time he tries to join it forces him to download them as if he doesn’t even have them. I don’t know if this is a result of using Hamachi or something, but some assistence would be appreciated. Thanks!

If the addons differ in any way, like on .gma and the other legacy OR they are different versions you would have to download it. I also know that when you join someone’s lan game you are forced to have the same addons.(Unless you have multiplayer downloads off) [del]If one of your computers can handle it and you plan on playing together a lot, I recommend you make a local server (not ran off of gmod)
http://wiki.garrysmod.com/page/Hosting_A_Dedicated_Server <-- that should help
[/del] Running a local server for 2 people won’t likely be beneficial.