On 4/26/14, 9:44 AM, Carlos Pignataro (cpignata) wrote:
> Hi,
> 
> I do not think that "L3 VPN" appropriately qualifies the type of "VPN 
> Leakages" described in this document. It seems to me that "split tunnel AF 
> bug" describes it better. One definition of "L3VPN" is at 
> https://tools.ietf.org/html/rfc4031#section-3.1
> 
> It would also be interesting to ask the L3VPN WG about it.
> 
> Please find a couple more comments inline on the Abstract.
> 
> On Apr 24, 2014, at 6:11 AM, [email protected] wrote:
> 
>>
>> A New Internet-Draft is available from the on-line Internet-Drafts 
>> directories.
>> This draft is a work item of the Operational Security Capabilities for IP 
>> Network Infrastructure Working Group of the IETF.
>>
>>        Title           : Layer-3 Virtual Private Network (VPN) tunnel 
>> traffic leakages in dual- stack hosts/networks
>>        Author          : Fernando Gont
>>      Filename        : draft-ietf-opsec-vpn-leakages-05.txt
>>      Pages           : 10
>>      Date            : 2014-04-24
>>
>> Abstract:
>>   The subtle way in which the IPv6 and IPv4 protocols co-exist in
>>   typical networks, together with the lack of proper IPv6 support in
>>   popular Virtual Private Network (VPN) tunnel products, may
> 
> I believe that "lack of proper IPv6 support in popular VPN tunnel products" 
> needs to be either substantiated or dropped. Also, it's not clear to me what 
> is "proper support" versus (perhaps) "improper support".

I disagree and i think the comments from present and past implementers
(myself included) corroborate this assertion. naming specific products
doesn't actually serve a useful purpose.

>>   inadvertently result in VPN tunnel traffic leaks.  That is, traffic
>>   meant to be transferred over an encrypted and integrity protected VPN
>>   tunnel
> 
> The title says "L3VPN Tunnels", but in general L3VPN Tunnels do not imply 
> encryption. IP-in-IP, GRE, and L2TPv3 can create L3VPN tunnels without 
> encryption or integrity protection.
> 
>> may leak out of such tunnel and be sent in the clear on the
>>   local network towards the final destination.  This document discusses
>>   some scenarios in which such VPN tunnel traffic leakages may occur as
>>   a result of employing IPv6-unaware VPN software.
> 
> This paragraph seems closer to describing the actual problem: "IPv6 unaware 
> tunnel encapsulation" -- it seems to me that this is not a "VPN" problem.
> 
> Lastly, please note that there are instances where the demultiplexing of IPv6 
> from IPv4 before tunnel encapsulation is a deliberate action: 
> http://www.cisco.com/c/en/us/td/docs/ios/12_0s/feature/guide/l2tpv29s.html#wp1276833
> 
> Thanks,
> 
> Carlos.
> 
>>  Additionally, this
>>   document offers possible mitigations for this issue.
>>
>>
>> The IETF datatracker status page for this draft is:
>> https://datatracker.ietf.org/doc/draft-ietf-opsec-vpn-leakages/
>>
>> There's also a htmlized version available at:
>> http://tools.ietf.org/html/draft-ietf-opsec-vpn-leakages-05
>>
>> A diff from the previous version is available at:
>> http://www.ietf.org/rfcdiff?url2=draft-ietf-opsec-vpn-leakages-05
>>
>>
>> Please note that it may take a couple of minutes from the time of submission
>> until the htmlized version and diff are available at tools.ietf.org.
>>
>> Internet-Drafts are also available by anonymous FTP at:
>> ftp://ftp.ietf.org/internet-drafts/
>>
>> _______________________________________________
>> OPSEC mailing list
>> [email protected]
>> https://www.ietf.org/mailman/listinfo/opsec
> 
> _______________________________________________
> OPSEC mailing list
> [email protected]
> https://www.ietf.org/mailman/listinfo/opsec
> 


Attachment: signature.asc
Description: OpenPGP digital signature

_______________________________________________
OPSEC mailing list
[email protected]
https://www.ietf.org/mailman/listinfo/opsec

Reply via email to