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What IPsec protect in tunnel mode?
Tunnel and Transport Mode IPsec can be used in tunnel mode or transport mode. Tunnel mode provides confidentiality (ESP) and/or authentication (AH) to the entire original packet, including the original IP headers. New IP headers are added (with the source and destination addresses of the IPsec gateways).
What IPsec mode is more secure?
Tunnel mode is most commonly used to encrypt traffic between secure IPSec gateways, such as between the Cisco router and PIX Firewall (as shown in example A in Figure 1). The IPSec gateways proxy IPSec for the devices behind them, such as Alice’s PC and the HR servers in Figure 1.
What are the headers of an IPSEC tunnel Mode packet?
An IPsec Tunnel mode packet has two IP headers—an inner header and an outer header. The inner header is constructed by the host; the outer header is added by the device that is providing security services. IPsec defines Tunnel mode for both the Authentication Header (AH) and Encapsulating Security Payload (ESP).
How is a packet protected in tunnel mode?
In tunnel mode, the entire packet is inside the ESP header. The packet in Figure 6–3 is protected in tunnel mode by an outer IPsec header and, in this case, ESP, as shown in the following figure. IPsec policy provides keywords for tunnel mode and transport mode.
How is tunnel keyword used in IPSec policy?
IPsec policy provides a tunnel keyword to select an IP tunneling network interface. When the tunnel keyword is present in a rule, all selectors that are specified in that rule apply to the inner packet. The following figure shows an IP header with an unprotected TCP packet. In transport mode, ESP protects the data as shown in the following figure.
Which is more secure transport mode or tunnel mode?
Tunnel mode is more secure than Transport mode because it encrypts both the payload and the header. IPsec in Tunnel mode is normally used when the ultimate destination of a packet is different than the security termination point.