As folks are becoming more focused on IPv6, developing a solid security strategy with regards to IPv6 networking is essential. Needing some training on IPv6 or IPv6 Security - check out our courses here.
That said, one way to gather information or take down an IPv6 network is to use a SYN FLOOD attack.
Wikipedia deines a
A SYN flood is a form of denial-of-service attack in which an attacker sends a succession of SYN requests to a target's system in an attempt to consume enough server resources to make the system unresponsive to legitimate traffic.
This is a well known attack in IPv4 networks and carries forward into IPv6.
Using Wireshark, here is a brief view of what it looks like:
Looking at the attack, it is fascinating what is happening.
Clearly the attack has determined the network to be FC00:1::/64 which is actually correct.
Then we see TCP SYN's being sent out followed by ICMPv6 Neighbor Solicitations to the SNMA address (look at packets 6 and 7 for example). This causes the Firewall to not shut doen the port as these "may" be legitimate packets.
The randomness of the IID seems to indicate that there was no desire to "scan" or find any devices. Instead, what is happening is an attempt to fill up/poison the IPv6 Neighbor Tables (these are IPv6's replacement for ARP tables in the IPv4 world).
You will note we are using our IPv6 default profile - it can be found in our profile repository here.
And, if you would like a copy of this .pcap-ng file for your own self study, you can download it here.