crecode.com

In this chapter, the term IP packet refers to either an IPv4 datagram or an IPv6 packet. in .NET Print QR Code JIS X 0510 in .NET In this chapter, the term IP packet refers to either an IPv4 datagram or an IPv6 packet.




How to generate, print barcode using .NET, Java sdk library control with example project source code free download:
In this chapter, the term IP packet refers to either an IPv4 datagram or an IPv6 packet. use none none writer toassign none with none 2/5 Industrial CHAPTER 8 / IP SECURITY Table 8.1 Tunnel Mode and Transport Mode Functionality Transport Mode SA AH Authenti none none cates IP payload and selected portions of IP header and IPv6 extension headers. Encrypts IP payload and any IPv6 extension headers following the ESP header. Encrypts IP payload and any IPv6 extension headers following the ESP header.

Authenticates IP payload but not IP header.. Tunnel Mode SA Authenticat none none es entire inner IP packet (inner header plus IP payload) plus selected portions of outer IP header and outer IPv6 extension headers. Encrypts entire inner IP packet. Encrypts entire inner IP packet.

Authenticates inner IP packet.. ESP ESP with Authentication 8.2 IP SECURITY POLICY Fundamental to the operation of IPsec is the concept of a security policy applied to each IP packet that transits from a source to a destination. IPsec policy is determined primarily by the interaction of two databases, the security association database (SAD) and the security policy database (SPD). This section provides an overview of these two databases and then summarizes their use during IPsec operation.

Figure 8.2 illustrates the relevant relationships..

Security Associations A key conce pt that appears in both the authentication and confidentiality mechanisms for IP is the security association (SA). An association is a one-way logical connection between a sender and a receiver that affords security services to the traffic carried on it. If a peer relationship is needed for two-way secure exchange, then two security associations are required.

Security services are afforded to an SA for the use of AH or ESP, but not both.. Key exchange IKEv2 SPD Security policy database IKE SA IKEv2 SPD IPsecv3 Security policy database IPsecv3 IPsec SA Pair Security association database ESP protects data Security association database Figure 8.2 IPsec Architecture 8.2 / IP SECURITY POLICY A security none for none association is uniquely identified by three parameters. Security Parameters Index (SPI): A bit string assigned to this SA and having local significance only. The SPI is carried in AH and ESP headers to enable the receiving system to select the SA under which a received packet will be processed.

IP Destination Address: This is the address of the destination endpoint of the SA, which may be an end-user system or a network system such as a firewall or router. Security Protocol Identifier: This field from the outer IP header indicates whether the association is an AH or ESP security association. Hence, in any IP packet, the security association is uniquely identified by the Destination Address in the IPv4 or IPv6 header and the SPI in the enclosed extension header (AH or ESP).

. Security Association Database In each IPs none for none ec implementation, there is a nominal2 Security Association Database that defines the parameters associated with each SA. A security association is normally defined by the following parameters in an SAD entry. Security Parameter Index: A 32-bit value selected by the receiving end of an SA to uniquely identify the SA.

In an SAD entry for an outbound SA, the SPI is used to construct the packet s AH or ESP header. In an SAD entry for an inbound SA, the SPI is used to map traffic to the appropriate SA. Sequence Number Counter: A 32-bit value used to generate the Sequence Number field in AH or ESP headers, described in Section 8.

3 (required for all implementations). Sequence Counter Overflow: A flag indicating whether overflow of the Sequence Number Counter should generate an auditable event and prevent further transmission of packets on this SA (required for all implementations). Anti-Replay Window: Used to determine whether an inbound AH or ESP packet is a replay, described in Section 8.

3 (required for all implementations). AH Information: Authentication algorithm, keys, key lifetimes, and related parameters being used with AH (required for AH implementations). ESP Information: Encryption and authentication algorithm, keys, initialization values, key lifetimes, and related parameters being used with ESP (required for ESP implementations).

Lifetime of this Security Association: A time interval or byte count after which an SA must be replaced with a new SA (and new SPI) or terminated, plus an indication of which of these actions should occur (required for all implementations).. Nominal in the sense that the functionality provided by a Security Association Database must be present in any IPsec implementation, but the way in which that functionality is provided is up to the implementer..
Copyright © crecode.com . All rights reserved.