Subject: [lisp] Anycast PETR range for interworking

From: "Job W. J. Snijders" <[email-masked]>
Date: Fri, 26 Feb 2010 12:23:32 +0100

Dear Fellow LISPers,

I quote from the interworking-01 draft "Proxy Egress Tunnel Routers (PETRs)
allow for LISP-NR sites to communicate with non-LISP sites in the case where
the access network does not allow for the LISP-NR site send packets with the
source address of the site's EID(s)." 

The two main reasons for using a PETR: 
	- "Avoiding strict uRPF failures - Some provider's access network require 
	the source of the packets emitted to be within the addressing scope of the
	 access networks."
	- "Traversing a different IP Protocol - A LISP site may want to transmit
	 packets to a non-LISP site where the some of the intermediate network
	 does not support an IP protocol (v4 or v6)."

Currently there are a handful PETR devices that I know of, which all have
different IP addresses. To me it seems that the PETR devices could use IP
addresses that are anycasted to the internet in a similar way the 6to4 prefix
is anycasted. This would allow for ease of configuration on LISP-NR sites and
would serve as a service to the public. 

I want to propose to RIPE to assign a IPv4 /24 and an IPv6 equivalent for
"Experimental Purposes"[1] to us (the current testbed). Requesting PI or PA
space dedicated for this purpose does not seem applicable because of various
reasons. The advantage of "experimental ranges" is that because of their
temporary nature RIPE will be less strict compared to 'normal' requirements:
within these ranges we can only account for 1 IPv4 /32 and 1 IPv6 /128. 

I already have a sponsoring LIR[2], and through my sponsor I will announce
this prefix in europe, and would encourage other people that have PETR capable
devices to start using this prefix too, thus increasing the PETR capacity and
making the mechanism more resilient. Also I can take the lead in documenting
the experiment and and making sure we adhere RIPE policies. 

If the experiment succeeds we want to move forward, I guess we should write a
draft explaining and defending the need for a "Special Purpose" prefix,
similar to RFC 3068, in addition to the interworking draft. 

Any thoughts on the subject would be appreciated very much! If the list
supports me I will contact RIPE and start the paperwork. 

Kind regards,

Job Snijders

[1] http://www.ripe.net/docs/ripe-389.html
[2] InTouch NV, Amsterdam, http://www.intouch.eu/

---

From: Sam Hartman <[email-masked]>
Date: Fri, 26 Feb 2010 07:16:37 -0500

>>>>> "Job" == Job W J Snijders <[email-masked]> writes:

    Job> which all have different IP addresses. To me it seems that the
    Job> PETR devices could use IP addresses that are anycasted to the
    Job> internet in a similar way the 6to4 prefix is anycasted. This

As Robbin and I have discussed, we believe that PETR devices need some
for of authentication and access control between the PETR and ITR.  This
is needed to avoid the PETR being used to assist in address spoofing
attacks.

So, while anycast may be useful, I don't think it will be nearly as
useful as say for 6to4.