This isn't on the level of some other providers, they'll still null route you if you go over an unspecified amount of traffic. IIRC they use Juniper and Corero.

This is the reply I got from their support, just a few days ago:

>In short, our DDoS protection works by filtering out DoS-like traffic and is applied via the Linode network, so all Linodes are automatically protected. If your server were to be on the receiving end of a larger attack that impacts the Linode's host, we would need to prevent your server from receiving traffic until the attack ends. If you're concerned that you might be the target of a large DoS attack, there are a number of third-party DDoS mitigation services that you can use alongside your Linode.

>We aren't able to provide specific numbers since effects can vary depending on the attack. If you wanted to be sure your Linode is protected, we would recommend utilizing a third-party DDoS protection service overtop of your Linode's included protection. You also have the option of waiting to apply third-party protection until a null route is found to be necessary.