SYN flood on [2.0.33]

• Messages sorted by: [ date ][ thread ][ subject ][ author ]
• Next message: Stephen R. van den Berg: "Re: Thread+network crashes in 2.0/2.1"
• Previous message: Gadi Oxman: "Re: IDE still misbehaving in pre-2.1.89-4 [WAS: Can't set UltraDMA mode 2 on Quantum Fireball SE]"
• Next in thread: Andi Kleen: "Re: SYN flood on [2.0.33]"
• Reply: Andi Kleen: "Re: SYN flood on [2.0.33]"

There was recently a following problem :

Kernel stop responding on 25th port, believing all income connections
are flood. There are a lot "Warning: possible SYN flood from ..." messages.
All of them came from mail relays, e.g. nic.funet.fi, portcullis.itis.com,
etc, including our local mail relays. I don't believe this was a real attack.

There are also a lot of "validated probe" messages , but I never could
reach 25th port telnetting on it. I got "connected" once, but nothing followed.
In other cases connection failed on timeout.

reboot healed this, of course.

So the question is what made such things to happen, how I can prevent this
or correct the problem without reboot()ing.

Thanx beforehand.

Bye.

--
Man is the measure of all things.
		-- Protagoras

--
    With best of best regards, Pawel S. Veselov (aka Black Angel)
                   Internet e-mail : vps@mindless.com
    Web page : http://www2.math.spbu.ru/~vps/ | ICQ UIN : 5252265


-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu






 Next message: Stephen R. van den Berg: "Re: Thread+network crashes in 2.0/2.1"
 Previous message: Gadi Oxman: "Re: IDE still misbehaving in pre-2.1.89-4 [WAS: Can't set UltraDMA mode 2 on Quantum Fireball SE]"

 Next in thread: Andi Kleen: "Re: SYN flood on [2.0.33]"
 Reply: Andi Kleen: "Re: SYN flood on [2.0.33]"