There's nothing you can do against a DDoS when you are a "standard" ISP subscriber. The bandwidth of your ISP connection is so low, compared with the bandwidths that DDoSes take up nowadays, that your connection will always saturate. Filtering at your end will not make a difference.
Theoretically speaking, your ISP could do something, by filtering before the packets enter your connection (for example by filtering at the edges of their network), but practically they don't do that because it requires resources e.g. money.
If we are talking about a server, then you can buy protection. You might have noticed an error message from CloudFlare when you browse to the BC forums but don't get a reply. CloudFlare is a company that offers (D)DoS protection, Bleeping Computer is a customer.
PS: to (D)DoS your connection the attackers need to know your IP address.
SANS ISC Senior Handler
Microsoft MVP 2011-2016 Consumer Security, Windows Insider MVP 2016-2019
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