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Chapter 9. Securing Data Transmission and Authentication. Securing Traffic with IPSec. IPSec allows us to protect our network from within IPSec secures the IP protocol IPSec has two principle goals: To protect the contents of IP packets
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Chapter 9 Securing Data Transmission and Authentication
Securing Traffic with IPSec • IPSec allows us to protect our network from within • IPSec secures the IP protocol • IPSec has two principle goals: • To protect the contents of IP packets • To provide defense against network attacks through packet filtering and the enforcement of trusted communication. • Attacks that IPSec can prevent and reduce: Packet Sniffing Man in the Middle Data Modification Denial of Service Identity Spoofing
Understanding IPSec • IPSec can be deployed in the following scenarios: • LAN – Client/Server and peer to peer LANs • WAN – Router to Router • Remote Access – Dial up clients and Internet access from private networks • Both sides require a shared IPSec policy to establish the security settings that will be used. • IPSec can be configured to use one of two modes: • Transport mode – Use this mode when you require packet filtering and when you require end-to-end security. • Tunnel mode – Use tunnel mode for site-to-site communications that cross the Internet. Gateway-to-Gateway protection
Understanding IPSec contd. • IPSec provides security using a combination of individual protocols. • Authentication Header (AH) – protocol provides authentication, integrity, and anti-replay for the packet. This protocol does not encrypt, but protects from modification. • Encapsulating Security Payload (ESP) – provides confidentiality of the packet (encryption).
Understanding Security Associations • SA – is the combination of security services, protection mechanisms, and keys agreed to by communicating peers. • When traffic meets a filter that is defined in the policy, the security parameters much then be negotiated. The SA is what is agreed upon. • Internet Key Exchange (IKE) – an algorithm used to generate the secret keys agreed upon in the SA.
IPSec Policies • Policies are the security rules that define the desired security levels negotiated in the SA. • The policy also define which traffic is “interesting” and whether or not to negotiate IPSec or just send the information with out modification. • Components of a Policy: • Tunnel setting • Network Type • IP filter • IP protocol Port • IP filter list • Filter Action • Authentication method
Creating IPSec Policies • Go to local security Policy • Use “IP security policies” for policies that must be compatible with versions of Windows older than Vista/Server 2008 • Use Windows Firewall with Advanced Security for Vista/Server 2008 systems.
Breaking it all down • Example on board
Configuring Network Authentication • When a computer connects to a network it must be authenticated. Typically this is done through Active Directory and Kerberos. • However, if there is no AD domain or you have older clients you may need to change the Authentication type to NTLM. • Computer Configuration->Policies->Windows Setting-> Security Settings->Security Options->Network Security:NTLM