[0.13.1] Unable to see friend's public server

[Skumby]

I was playing with a friend yesterday fine. Upon both of us updating to 0.13.1 today, I was not able to see his server, nor was he able to see my server. We tried both the save file from yesterday and creating a new game, without success.

0.001 2016-06-29 13:01:59; Factorio 0.13.1 (Build 22864, win64, steam)
0.001 Operating system: Windows 10
0.001 Program arguments: "C:\Program Files (x86)\Steam\steamapps\common\Factorio\bin\x64\Factorio.exe"
0.001 Read data path: C:/Program Files (x86)/Steam/steamapps/common/Factorio/data
0.001 Write data path: C:/Users/Andrew/AppData/Roaming/Factorio
0.001 Binaries path: C:/Program Files (x86)/Steam/steamapps/common/Factorio/bin
0.017 Graphics options: [FullScreen: true] [VSync: true] [UIScale: 100%] [MultiSampling: OFF] [Graphics quality: normal] [Video memory usage: high] [Light scale: 20%] [Screen: 0] [DXT: false]
0.019 Available display adapters: 2
0.019 [0]: \\.\DISPLAY1 - NVIDIA GeForce GTX 680 {0x05, [0,0], 1920x1080, 32bit, 120Hz}
0.019 [1]: \\.\DISPLAY2 - NVIDIA GeForce GTX 680 {0x01, [-1600,5], 1600x1200, 32bit, 60Hz}
0.019 Create display on adapter 0. Size 1280x720 at position [310, 162].
0.069 Initialised Direct3D:[0] NVIDIA GeForce GTX 680; driver: nvd3dumx.dll 10.18.13.6519
0.080 Video memory size (dedicated video/dedicated system/shared system/available): 1989/0/8168/4088 MB
0.109 Desktop composition is active.
0.175 Loading mod core 0.0.0 (data.lua)
0.179 Loading mod base 0.13.1 (data.lua)
0.283 Checksum for core: 1399339455
0.283 Checksum for mod base: 2679425721
0.795 Initial atlas bitmap size is 16384
0.797 Created atlas bitmap 16384x6371
1.060 Created atlas bitmap 4096x968
7.901 Sprites loaded
7.901 Convert atlas 4096x968 to: trilinear-filtering
8.125 Loading sounds...
9.507 Custom inputs active: 0
9.542 Factorio initialised
17.360 Info WindowsUDPSocket.cpp:59: Opening socket at port (0)
36.389 Info WindowsUDPSocket.cpp:159: Socket closed
38.006 Steam API shutdown.
38.009 Goodbye