[Mip6-firewall] HA behind firewall - proposal

[Vijay Devarapalli]

Yaron Sheffer wrote:
> I agree that we need to add an IKEv2 pinhole. But note that the mere 
> fact of having an IKEv2 exchange from address X does not mean that it 
> was successful and all later ESP packets from the same address are 
> legitimate.

It will be separate pin holes. The first one would say allow all 
IKE_SA_INIT, IKE_AUTH, etc.. messages through to a well known address
like the home agent address. IKEv2 messages to other addresses may be
blocked.

The second pinhole would say all ESP protected packets (both transport
mode and tunnel mode) to a well known address like the home agent
address. All other ESP protected packets may be dropped. The firewall
has to trust the home agent to drop those ESP protected packets that
do not pass all the IPsec checks.

Vijay

> 
> 
>     Yaron
> 
> 
> Vijay Devarapalli wrote:
> 
>> Suresh,
>>
>> This does address bootstrapping the MIPv6 home address via the
>> IKEv2 exchange. The home address would be unknown until then.
>>
>> What might want to add is to require the firewall to allow all
>> IKEv2 messages also through to the home agent address.
>>
>> Vijay
>>
>> Suresh Krishnan wrote:
>>   
>>> Hi Folks,
>>>    I feel that a BCP for firewall admins would be the best way to 
>>> address the HA being behind a firewall.
>>>
>>> * This firewall MUST NOT drop IPSec traffic bound to the Home Agent. The 
>>> home agent address needs to be configured on the firewall to explicitly 
>>> allow all IPSec traffic. If this traffic is found to be not legitimate, 
>>> a host based firewall or the HA implementation can drop the packet
>>> * If an MN is providing services (i.e. allows incoming connections), the 
>>> firewall needs to allow connection requests with the MN HoA as the 
>>> destination address. The address(es) of such MN(s) need to be configured 
>>> on the firewalls
>>> * The firewall MUST permit all HoT messages with a destination address 
>>> of a known MN HoA, if there was a HoTI message sent out with the same 
>>> source address. The firewall might verify if the home test init cookie 
>>> matches the one sent
>>>
>>> I believe that these rules are reasonable, but some of these might not 
>>> be acceptable to firewall admins. But, since the home network is 
>>> providing a service, there is not much room to maneuver without changing 
>>> the MIP6 protocol and end nodes (which might be another option).
>>>
>>> Cheers
>>> Suresh
>>> _______________________________________________
>>> Mip6-firewall mailing list
>>> Mip6-firewall at zeke.ecotroph.net
>>> https://zeke.ecotroph.net/mailman/listinfo/mip6-firewall
>>>     
>>
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