[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

RE: Observation from tonight's Bar BOF on IPsec Failover



Hello Charlie,

 

The summary is good and thanks for sharing it with us. As one of the participants in yesterday’s discussion, my observation was that we went into solution discussion too soon w/o having any discussion on the scenario and scope for the proposed work item. I believe there are fundamental differences among the group of participants on the scope/scenario.

 

However, we spent a good amount of time discussing a solution that is being proposed by a few of the participants. I see that the solution has major issues (I brought up one of them during the discussion, regarding two gateways coming up at the same time in the network for the same host/client simply because there was a transient loss of connection at the host with the existing gateway). Moreover, a host assisted ticket based solution will run into deployment issues in a wireless network where access and paging channels are scarce resources.

 

Regarding the usefulness of maintaining the internal IP address, it is a fundamental requirement if applicability statement includes mobile IP. Even otherwise, it will be a very strong requirement if the solution is deployed in the real world networks (e.g. 3G wireless networks).

 

If requirement 4 is not addressed, it won’t be a failover solution; it will be rather optimized re-connection mechanism w/Io IP session continuity. Without gateway – gateway communication, we still have to live with the scenario where the host/client brings up multiple IPsec/IKEv2 sessions simply because it is confused, or in a radio fade zone, or simply it is a rouge host/client.  

 

I strongly believe that a scalable and deployable IPsec/IKEv2 failover solution must include gateway – gateway communication. It will address all the requirements that you listed below in a much more secure, scalable, and efficient way. I still believe that is how we need to address it. The solution and the direction that some of the participating members want to take unfortunately exclude that in their solution.

 

In summary, I would like to say, it is not that we don’t want a solution for IPsec/IKEv2 failover. It is the way a solution is being pushed here is what not acceptable. The scope of the work must include gateway – gateway communication for the stated reasons.

 

BR,

Kuntal

 

 


From: owner-ietf-ipsec-failover@xxxxxxxxxxxxx [mailto:owner-ietf-ipsec-failover@xxxxxxxxxxxxx] On Behalf Of Charlie Kaufman
Sent: Wednesday, December 05, 2007 12:30 AM
To: ietf-ipsec-failover@xxxxxxxx
Cc: tim.polk@xxxxxxxx
Subject: Observation from tonight's Bar BOF on IPsec Failover

 

I noticed something at tonight’s Bar BOF that I believe will be a critical factor in whether an eventual BOF succeeds: different groups seemed to have very different scenarios they were trying to address (which is OK) and they didn’t seem to understand or respect the important scenarios of the other groups (which is not).

 

As I see it, there are four things the IPsec Failover protocol is trying to save over just redoing a fresh IKE exchange in the case of failover. The first two relate solely to performance; the second two have user visible implications.

 

1)   The cost of a fresh Diffie-Hellman calculation.

2)   The cost of two round trips during the exchange.

3)   Rerunning an EAP exchange that could involve user participation.

4)   Keeping the “internal” IP address so that open tunneled TCP connections can stay open and applications that cache the client’s IP address don’t need to be restarted.

 

The protocol being proposed could facilitate achieving all of those goals in their particular scenarios. Some people seemed to believe that (4) was the really important consideration and the others were nice-to-have. Others seemed to think that 1-3 were the important considerations and (4) was unrealistic. It is unrealistic in some scenarios, but very realistic in others. MOBIKE provides such capabilities, and it would be worth exploring how much overlap there is in the goals of these two protocols. There may have been people who valued different subsets of those features who weren’t quite as vocal.

 

If these groups want to jointly present a proposal (and the chances of success are much greater if they do), they need to learn to (at least in “public”) speak respectfully of the needs of the other groups – which probably implies understanding them. It appears there is an “everybody wins” protocol on the table; we just all need to get behind it (and its successors).

 

               --Charlie

"This email message and any attachments are confidential information of Starent Networks, Corp. The information transmitted may not be used to create or change any contractual obligations of Starent Networks, Corp. Any review, retransmission, dissemination or other use of, or taking of any action in reliance upon this e-mail and its attachments by persons or entities other than the intended recipient is prohibited. If you are not the intended recipient, please notify the sender immediately -- by replying to this message or by sending an email to postmaster@xxxxxxxxxxxxxxxxxxx -- and destroy all copies of this message and any attachments without reading or disclosing their contents. Thank you."