You can use an online whois to lookup destination ip addresses as Habitual probably did for you
you can google port numbers (or look at /etc/services) to get an idea what service is using that port
6771 is often used by a p2p service called transmission, perhaps someone on your lan is using this?
If you have run a p2p app recently, and you have quit the application, peers will still try to connect for a while and your firewall will reject them. One of those 3 lines has a TTL of one, and all have a local ip of 192.168.88.199 - this sounds like local broadcast traffic
one of my favourites is (as root)
this will tell you what services you have running and which ports they are using
gives similar info
you should be able to match this info with your log output to help you see what is going on on your network.