[CentOS] Optimal VPN

Fri Dec 10 15:37:38 UTC 2010
Ross Walker <rswwalker at gmail.com>

On Dec 10, 2010, at 8:48 AM, Les Mikesell <lesmikesell at gmail.com> wrote:

> On 12/10/10 2:42 AM, David Sommerseth wrote:
>> On 09/12/10 17:29, Steve Clark wrote:
>>> On 12/09/2010 10:30 AM, David Sommerseth wrote:
>>>> On 25/11/10 14:12, J.Witvliet at mindef.nl wrote:
>> [...snip...]
>>>> 
>>>>> Furthermore, openvpn is only compatible with openvpn, while using ipsec you might be able to connect to other boxes.
>>>>> 
>>>> That is mostly true, except for those vendors adding their own
>>>> proprietary extensions to their ipsec implementations ... thus making it
>>>> a vendor lock-in again.
>>>> 
>>>> 
>>> Hmm... We run ipsec, (using ipsec-tools on both Linux and FreeBSD),
>>>  to Cisco, Juniper, NetScreen and many others without problem.
>>> What vendors are you talking about?
>> 
>> I don't have personal hand-on experiences with ipsec issues.  However, I
>> would expect things to work flawlessly as long as you don't enable
>> vendor specific features, or if you enable compatible features.
>> 
>> <http://www.veiligmobiel.com/IPsecCompatibility.htm>
>> 
>> And I believe it will be even more differences if you try to use a
>> "tunnelled" setup versus a "transport" setup, where the tunnelled mode
>> will act more a like a SSL based VPN.  If I have understood it correctly.
> 
> On Ciscos I've always run GRE tunnels with only the GRE packets going through 
> ipsec to get interfaces that can handle dynamic routing protocols, multicast, 
> etc.  Is there a way to get that kind of tunnel interface with ipsec alone?

No, because IPSec tunnel mode works for a given routable network segment and multicast routing isn't handled.

I too use GRE tunnels over IPSec transport mode for site-to-site connectivity, so I can support OSPF and other multicast protocols.

For road warriors I use either l2tp (windows) or openvpn (Linux).

-Ross