Cisco Cisco Packet Data Gateway (PDG)
mode
Configures the security of IP datagrams based on header placement. Tunnel mode applies security to a
completely encapsulated IP datagram, while Transport does not. Default is Tunnel mode.
completely encapsulated IP datagram, while Transport does not. Default is Tunnel mode.
Product
ePDG
PDIF
SCM
Privilege
Security Administrator, Administrator
Command Modes
Exec > Global Configuration > Context Configuration > IPSec Transform Set Configuration
configure > context context_name > ipsec transform-set set_name
Entering the above command sequence results in the following prompt:
[
context_name
]
host_name
(config-context-vrf)#
Syntax Description
mode { transport | tunnel }
default mode
default mode
transport
In Transport mode, the IPSec header is applied only over the IP payload, not over the IP header in front of it.
The AH and/or ESP headers appear between the original IP header and the IP payload, as follows:
The AH and/or ESP headers appear between the original IP header and the IP payload, as follows:
Original IP header, IPSec headers (AH and/or ESP), IP payload (including transport header).
Transport mode is used for host-to-host communications and is generally unsuited to PDIF traffic.
tunnel
In Tunnel mode, the original IP header is left intact, so a complete IP datagram is encapsulated, forming a
virtual tunnel between IPSec-capable devices. The IP datagram is passed to IPSec, where a new IP header is
created ahead of the AH and/or ESP IPSec headers, as follows:
virtual tunnel between IPSec-capable devices. The IP datagram is passed to IPSec, where a new IP header is
created ahead of the AH and/or ESP IPSec headers, as follows:
New IP header, IPSec headers (AH and/or ESP), old IP header, IP payload.
Tunnel mode is used for network-to-network communications (secure tunnels between routers) or
host-to-network and host-to-host communications over the Internet.
host-to-network and host-to-host communications over the Internet.
This is the default setting for this command.
Command Line Interface Reference, Modes I - Q, StarOS Release 19
101
IPSec Transform Set Configuration Mode Commands
mode