When connecting, client.connect() returns 0
You need to provide more than just the IP address. The Arduino also needs to know the default router address in order to send packets to the right place.

Unfortunately there isn't a way of giving it that information without also giving it a DNS address, so you have to do that as well.

You need to have:

IPAddress gateway(192, 168, 1, 1);
IPAddress dns(8, 8, 8, 8);
IPAddress ip(192, 168, 1, 25);


And then in setup:

Ethernet.begin(mac, ip, dns, gateway);


Alternatively you can rely on DHCP to give you all the details, and just use:

Ethernet.begin(mac);