Did I get connection flooded?

[SolidSonicTH]

My router started acting really erratic, dropping my AiMesh network and being unusable.

I did some digging in my logs and I found several entries that looked like this:

Aug 7 22:56:59 vpnserver1[2289]: 104.35.248.96:65051 MULTI: new incoming connection would exceed maximum number of clients (1024)
Aug 7 22:56:59 vpnserver1[2289]: 104.35.254.146:52684 MULTI: new incoming connection would exceed maximum number of clients (1024)
Aug 7 22:56:59 vpnserver1[2289]: 104.35.228.36:45170 MULTI: new incoming connection would exceed maximum number of clients (1024)
Aug 7 22:56:59 vpnserver1[2289]: 104.35.228.36:42075 MULTI: new incoming connection would exceed maximum number of clients (1024)
Aug 7 22:56:59 vpnserver1[2289]: 104.35.228.36:50856 MULTI: new incoming connection would exceed maximum number of clients (1024)
Aug 7 22:56:59 vpnserver1[2289]: 104.35.228.36:53899 MULTI: new incoming connection would exceed maximum number of clients (1024)
Aug 7 22:56:59 vpnserver1[2289]: 104.35.228.36:5458 MULTI: new incoming connection would exceed maximum number of clients (1024)
Aug 7 22:56:59 vpnserver1[2289]: 104.35.228.36:60458 MULTI: new incoming connection would exceed maximum number of clients (1024)
Aug 7 22:56:59 vpnserver1[2289]: 104.35.228.36:20185 MULTI: new incoming connection would exceed maximum number of clients (1024)
Aug 7 22:56:59 vpnserver1[2289]: 104.35.228.36:34214 MULTI: new incoming connection would exceed maximum number of clients (1024)
Aug 7 22:56:59 vpnserver1[2289]: 104.35.228.36:27369 MULTI: new incoming connection would exceed maximum number of clients (1024)

Early on there were also some TCP requests from this 104.35.x.x subnet before it started giving these "exceed maximum" messages.

Did this cause my network to crap itself? Is it avoidable in the future (besides taking down my OpenVPN server)?

 

[ColinTaylor]

Possibly. The messages might be from a DoS attack, or just aggressive port scanning. Are you running your VPN server on the default port (UDP 1194) or some common port (e.g. TCP 443, TCP 10000, etc)? If so change to a non-common port and see if the problem goes away.

 

[SolidSonicTH]

It stopped after I reset the router a couple of times but, yes, I've got it using the default port value.