I'm using two routers in my home network, as described in this question (router B in the diagram). Therefore, router B is not accessible from the internet.
Going over the logs of this router, I was surprised to find what is logged as "SYN flood". I have several entries such as:
Nov 18 21:27:50 [ATTACK]: SYN Flood from 184.108.40.206
Nov 18 12:58:16 [ATTACK]: SYN Flood from 220.127.116.11
There are 3-4 such entries per day. I haven't noticed any disruption in use. The IPs are supposed to originate from companies such as Google or Microsoft, but something tells me they are spoofed.
- How can a router which is not accessible from the internet be a subject of such an attack? Note that I have full control of all devices connected to it, and they are all trustworthy/up-to-date.
- Does a SYN flood attack against a home router have a meaning anyway? I was under the impression SYN flood attacks are related to servers.
I also took a look at this question, and I should note I don't have any port forwarding active.