RE: Please help with this strangeness

["Shawn Jackson" <sjackson () horizonusa com>]

        That is weird networking! Usually ISP's assign a '30 block' to
people using NAT, in which case you only have one usable networking
address. The broadcast address lives at the 'top' of the block, so it
would not be 68. Maybe your assignment looks like:

68      -> Network Address
69      -> ISP Router
70      -> Your NAT/Firewall
71      -> Broadcast Address

Can you give more specifics on the address/networking details? From the
logs it looks like the ISP router is a little chatty and might be
configured that way. That's assuming that 69 is your ISP router. If 69
is a host, they could be keep-alive packets. They are TCP Type 8, which
is an Echo (TCP PING).

Shawn Jackson
Systems Administrator
Horizon USA
1190 Trademark Dr #107
Reno NV 89521

www.horizonusa.com
Email: sjackson () horizonusa com
Phone: (775) 858-2338
             (800) 325-1199 x338


-----Original Message-----
From: Michael Thompson [mailto:mike () thompsonmike co uk] 
Sent: Wednesday, January 14, 2004 7:03 PM
To: security-basics () securityfocus com
Subject: Please help with this strangeness

Hi Security-basics,


I was going through all my security logs today and I noticed something
a little odd, and wonderd if anyone could offer any insight? I am not
that good at detailed security!

I have a IPBlock assigned from my ISP, where 81.174.224.68 to
81.174.224.70.

As I understand it, 68 is a broadcast address, 69 is assigned to the
router, 70 is for a server, which I dont use at the present time.

Now, in my snort logs, which is connected to the outside of the
firewall I get the following logs..

[**] [1:483:2] ICMP PING CyberKit 2.2 Windows [**]
[Classification: Misc activity] [Priority: 3] 
01/15-02:49:35.625784 81.174.224.69 -> 81.174.224.70
ICMP TTL:111 TOS:0xA0 ID:45600 IpLen:20 DgmLen:92
Type:8  Code:0  ID:512   Seq:52213  ECHO
[Xref => http://www.whitehats.com/info/IDS154]

[**] [1:483:2] ICMP PING CyberKit 2.2 Windows [**]
[Classification: Misc activity] [Priority: 3] 
01/15-02:49:35.641759 81.174.224.69 -> 81.174.224.68
ICMP TTL:110 TOS:0xA0 ID:45598 IpLen:20 DgmLen:92
Type:8  Code:0  ID:512   Seq:51701  ECHO
[Xref => http://www.whitehats.com/info/IDS154]

[**] [1:483:2] ICMP PING CyberKit 2.2 Windows [**]
[Classification: Misc activity] [Priority: 3] 
01/15-02:49:35.642071 81.174.224.69 -> 81.174.224.70
ICMP TTL:110 TOS:0xA0 ID:45600 IpLen:20 DgmLen:92
Type:8  Code:0  ID:512   Seq:52213  ECHO
[Xref => http://www.whitehats.com/info/IDS154]

[**] [1:483:2] ICMP PING CyberKit 2.2 Windows [**]
[Classification: Misc activity] [Priority: 3] 
01/15-02:49:35.649566 81.174.224.69 -> 81.174.224.71
ICMP TTL:111 TOS:0xA0 ID:45601 IpLen:20 DgmLen:92
Type:8  Code:0  ID:512   Seq:52469  ECHO
[Xref => http://www.whitehats.com/info/IDS154]

[**] [1:483:2] ICMP PING CyberKit 2.2 Windows [**]
[Classification: Misc activity] [Priority: 3] 
01/15-02:49:35.665945 81.174.224.69 -> 81.174.224.71
ICMP TTL:110 TOS:0xA0 ID:45601 IpLen:20 DgmLen:92
Type:8  Code:0  ID:512   Seq:52469  ECHO
[Xref => http://www.whitehats.com/info/IDS154]  


Now, I thought of welchia or one of its many variants, and all
machines are clean, the DHCP records show only one machine on the
network connected mostly, thats my machine. It's clean.

What could be causing these broadcasts? Any one have any ideas?

-- 

Best regards,
 Michael (mike () thompsonmike co uk)
   
Join the American Non-Sequitur Society -- we don't make sense, but we do
like pizza. 

http://www.thompsonmike.co.uk/
PGP KeyID := 0xA9547E32

'To see a world in a grain of sand
And heaven in a wild flower
To hold infinity in the palm of your hand
And eternity in an hour'

Using TheBat! Version 2.02.3 CE
Running On Windows XP (2600, Service Pack 1)
Sent From OneAndOne

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