Security Basics mailing list archives
RE: IP announce DOS
From: "Burton Strauss" <BStrauss3 () comcast net>
Date: Fri, 10 Jun 2005 10:31:44 -0500
Fer sure... Addresses come in two kinds ... If the address space was allocated TO YOU, either directly by a regional registry (ARIN, RIPE, LACNIC, APNIC, AFRINIC, etc.) or by IANA, you have the rights to move it. If the address space was allocated to the ISP and subdivided, by them, then you DO NOT own it and can not move it. (Hence called portable and non-portable). You can check the status of a block by doing a whois query (whois -h whois.arin.net <address>) and you'll usually be able to figure it out from the output: $ nslookup www.skylist.net <snip /> Name: www.skylist.net Address: 66.219.61.67 $ whois -h whois.arin.net 66.219.61.67 [Querying whois.arin.net] [Redirected to rwhois.corenap.com:4321] [Querying rwhois.corenap.com] [rwhois.corenap.com] %rwhois V-1.5:003fff:00 cache02.ns.corenap.com (by Network Solutions, Inc. V-1.5.7.3) network:Auth-Area:66.219.32.0/19 network:ID:NET-66-219-61-0-1 network:Network-Name:NET-66-219-61-0-1 network:IP-Network:66.219.61.0/24 network:Org-Name:SKYLIST, Inc. network:Street-Address:Private Residence network:City:Austin network:State:TX network:Postal-Code:78720 network:Country-Code:US network:Tech-Contact:hostmaster () corenap com network:Updated:20050517 network:Updated-By:hostmaster () corenap com network:Class-Name:network %ok If you look, you'll see that there are two blocks - a big one to Corenet and a subnet to Skylist. If it were your space, portable, then you should only see the single allocation (sometimes this is listed in the output as 'NetType: Direct Allocation'. -----Burton -----Original Message----- From: Thomas Ng [mailto:thomasng () ida gov sg] Sent: Thursday, June 09, 2005 10:50 PM To: 'Alex Thurlow'; security-basics () securityfocus com Subject: RE: IP announce DOS Hi, Shouldn't it be that each ISPs have their own big blocks? Chances are, the class C given to you is in the middle of one of these huge blocks. I am not sure what is your agreement with the old and new ISP, but I don't think it is that simple to transfer the same set of IPs from one ISP to another. It is technically possible ... but I don't think it is that simple. Usually what I do when I change ISP is to just ask for a new set of IPs from the new ISP, change the DNS, allow the TTLs to run out and shift to the new sets of IP address. If you play with the DNS correctly, you can get minimal downtime, dependent on size and sophistication of your network. Rgds, Thomas
-----Original Message----- From: Alex Thurlow [mailto:buddychrist () gmail com] Sent: Thursday, June 09, 2005 5:24 AM To: 'security-basics () securityfocus com' Subject: IP announce DOS Importance: High I'm not positive this is the correct list to ask, but it is a security concern, so I thought I would. The company I work for had T1 lines running to our office provided by a local provider. We had our own C block of IPs being announced by them and routed to us over those T1s. Our relationship with them went sour (for many reasons I won't get
into
here), and we had to move to a different provider. We had the routing switched over to them. Everything was fine. Here it is a few weeks later, and suddenly our old provider starts announcing these IPs
again.
The end result is a partial DOS attack (hence writing to this list) as some people can't reach us. They won't stop the announcement. I
don't
know all the details on what they've said there as it's now gone to executives and legal people dealing with them. Is there anything we
can
do here from a network standpoint? Someone we can report them to?
How
do people protect themselves from just anyone announcing IPs that
aren't
theirs? Thanks in advance, Alex Thurlow ________________________________________ SKYLIST Email Marketing Solutions that Deliver Service You Can Trust You are receiving this email message from a representative of SKYLIST, Inc. 13171 Pond Springs Road, Austin, TX 78729 Toll Free: 877.250.2922 To cease all communication with SKYLIST, visit http://www.skylist.net/unsubscribe or send an email to unsubscribe () skylist com
Current thread:
- IP announce DOS Alex Thurlow (Jun 09)
- Re: IP announce DOS Micheal Espinola Jr (Jun 09)
- RE: IP announce DOS Burton Strauss (Jun 10)
- RE: IP announce DOS David Gillett (Jun 09)
- RE: IP announce DOS Thomas Ng (Jun 10)
- RE: IP announce DOS Burton Strauss (Jun 10)
- <Possible follow-ups>
- RE: IP announce DOS Andrew Shore (Jun 10)
- RE: IP announce DOS David Gillett (Jun 13)
- Re: IP announce DOS Alex Thurlow (Jun 10)
- Re: Re: IP announce DOS crabdog (Jun 13)
- Re: IP announce DOS Micheal Espinola Jr (Jun 09)