TO UNSUBSCRIBE: email "unsubscribe issforum" in the body of your message to
[EMAIL PROTECTED]  Contact [EMAIL PROTECTED] for help with any problems!
----------------------------------------------------------------------------

Hi Everyone,

Recently as well as detecting the normal inbound SYNfloods our RealSecure
v6.5 is detecting outbound SYNfloods which have spoofed source addresses
which reside within our network. The spoofed source addresses from our
network are Internet RIPE reserved but often are not live and active. The
destination port is often 80 but can be other ports.

My question is are these real SYNfloods? The sources address are not active
so if they are whatever is generating them is definitely spoofing the
source. 

I'm I right in thinking that the sensor cannot alert a SYNflood in the wrong
direction (as it can with backdoor signatures) because it only looks for
initial the SYN so the direction is always confirmed.

The alert appears as:- (please note I have substituted the addresses with
letters)

'SYNFlood' event detected by the RealSecure 'wcciss001' at 'x.x.x.x'.
Details:
 Source Address: 0.0.0.0
 Source Port: Any
 Source MAC Address: 08:00:20:9D:76:9D
 Destination Address: a.b.c.d  (where a.b.c.d is an external Internet
address)
 Destination Port: HTTP (80)
 Destination MAC Address: 08:00:20:C2:41:F8
 Time: 2002-07-05 09:11:19 UTC
 Protocol: TCP (6)
  Priority: medium
 Actions:
DISPLAY=Default:0,LOGDB=LogWithoutRaw:0,EMAIL=Default:0,SNMP=Default:0
 Event Specific Information:
  :SPOOFEDSRC: w.x.y.z (where w.x.y.z is an Internet address within our
datacentre)
*** Past Updates ***

Cheers

Jon Hughes
Network Analyst






*********************************************************************
This email  and any files  transmitted with it  are  confidential and
intended solely for the use of  the individual or entity to whom they
are addressed.  If you are  not the intended recipient,  you must not 
copy,  distribute or take any action in reliance on it.

Opinions  expressed  are  those of the  individual sender and  not of
Accenture.

If you have received this email in  error please notify the sender by
return email.

This footnote  confirms that  this email message has been checked for
viruses and inappropriate content.

Accenture reserves  the  right to monitor  email  communications from
external and internal sources for the purpose of ensuring correct and
appropriate use of Accenture communication equipment.


*********************************************************************



Reply via email to