The Internet Key Exchange (IKE) protocol, described in RFC 2409, is a key
management protocol standard which is used in conjunction with the IPsec
standard. IPsec can be configured without IKE, but IKE enhances IPsec by
providing additional features, flexibility, and ease of configuration for the IPsec
As mentioned in the T_IPsec chapter, IPsec security associations (SAs) must exist
in order for IPsec to protect network traffic. IKE manages those SAs on behalf of
IPsec, and automatically negotiates protection policies between IPsec peers. ...
A colleague once asked if I could help him understand the Diffie-Hellman key exchange protocol . . . without digging through the math. My answer was, “Yes, I can, but not easily.” Doing so requires a few diagrams because, in this particular case, a picture is worth several complex equations!
First things first. What is Diffie-Hellman (DH), and why should you care? DH is a mathematical algorithm that allows two computers to generate an identical shared secret on both systems, even though those systems may never have communicated with each other before.
This document serves as a design guide for those intending to deploy a site-to-site VPN based on IP
Security (IPsec). The designs presented in this document focus on Cisco IOS VPN router platforms.
The primary topology described in this document is a hub-and-spoke design, where the primary
enterprise resources are located in a large central site, with a number of smaller sites or branch offices
connected directly to the central site over a VPN. A high-level diagram of this topology is shown in
If a Security Association (SA) was previously established with Internet Key Exchange (IKE), what
will the following command do on the router?
A. It clears the SA symmetric key.
B. It clears the SA authentication key.
C. It deletes SA from the SA database.
D. It re-initializes every peer’s secret key.
It's an exciting time to be a competitive local exchange carrier (CLEC). With more carriers entering the
market, customers know they have many options for service. In fact, shopping around for the most
economical and best quality solution is becoming almost as basic for businesses as casual Fridays. For
new competitors, the key to getting customers' attention is finding a cost-effective way to deliver and
differentiate their services. The opportunity is clear when CLECs take a look at the exploding T1 service