FlexVPN Remote Access AnyConnect

Hi Laz,

I am extremely flattered by your compliments thank you. I am novice in the cisco world.
I think very highly of any individual who has acquired a CCIE. I see them as a role-model!

As of late networking and virtualization has become a hobby activity, subsequently this aids ones ability to learn rather quickly.

The issue came to my attention, after reading cisco article on IKEv2:

Under the proposal section it states:

“Manually configured IKEv2 proposals must be linked with an IKEv2 policy; otherwise, the proposals are not used in the negotiation”

consequently when a proposal is manually configured, this must be called/linked to a policy for example:

> Crypto IKEv2 proposal nwlesson_Proposal
> {Encryption Algorithm} e.g aes-cbc256 etc
*> {Integrity Algorithm} any hash of your choice e.g SHA etc *
> {Pseudo-Random function (PRF)} The PRF algorithm is the same as integrity algorithm, subesquently this does not to separately configured
{Diffie-Hellman(DH) Group}

I discovered yesterday in the lab, if you want this proposal to be utilised in the IKEv2 negotiation it MUST be called/linked by a policy for example:

Crypto IKEv2 Policy nwlesson_Policy
proposal nwlesson_Proposal (our proposal we configured above)

During a friday night dinner out with the family. I kept thinking, what happens if we don’t link the proposal to a policy?

Subsequently from 10pm untill 1am in the lab, I tested this theory. The configured proposal(encryption, Integrity, PRF algorithm and DH group) is not utilised in the SA_INIT exchange of the IKEv2 negotiation, if there isn’t a policy!

subsequently the question becomes, what proposal is being utilised if the one we configured isn’t being used in the exchange?

The answer: the default proposal!(remember smart defaults?)

now on this fantastic article by Rene that allowed me to learn about FlexVPN in general, I am very appreciative of this tutorial! it’s simply outstanding!

You will notice there is no policy that links the proposal, just a authorization policy which technically is completely different. Subsequently we are not using those proposal declared in the tutorial for the negotiation we are simply using default values provided by IOS:

in order to utilise the proposa(IKEV2_PROPOSAL)l that was declared in the lesson we must include the following in the tutorial guide:

Crypto IKEv2 Policy nwlesson_Policy
proposal IKEV2_PROPOSAL

many thanks again!

Taha