There have been a lot of good things written about Core’s recent release 0.13.1 and the advantages SegWit could provide. A less public feature, however, is that SegWit partitions the network; a 0.13.1 node only connects to other 0.13.1 nodes. Because of this, the SegWit soft fork has properties of a hard fork.
Starting a Bitcoin node means you connect to a network of other nodes. You find your first peers with the help of a public DNS seed, you connect to them, they tell you the addresses of other peers, and you connect to them. After establishing your set of friends, you can download the blockchain from them and help to spread transactions in the network.
Usually, your node is friend with a variety of other nodes; nodes of every country, old nodes, new nodes,