Glossary
GL-6
Cisco ASA 5500 Series Configuration Guide using ASDM
OL-20339-01
Dynamic NAT
See NAT and address translation.
Dynamic PAT
Dynamic Port Address Translation. Dynamic PAT lets multiple outbound sessions appear to originate 
from a single IP address. With PAT enabled, the adaptive security appliance chooses a unique port 
number from the PAT IP address for each outbound translation slot (xlate). This feature is valuable 
when an ISP cannot allocate enough unique IP addresses for your outbound connections. The global 
pool addresses always come first, before a PAT address is used. See also NAT, Static PAT, and xlate.
E
ECHO
See ping, ICMP. See also inspection engine.
EGP
Exterior Gateway Protocol. Replaced by BGP. The adaptive security appliance does not support EGP. 
See also BGP.
EIGRP
Enhanced Interior Gateway Routing Protocol. The adaptive security appliance does not support 
EIGRP.
EMBLEM
Enterprise Management BaseLine Embedded Manageability. A syslog format designed to be 
consistent with the Cisco IOS system log format and is more compatible with CiscoWorks 
management applications.
encryption
Application of a specific algorithm or cipher to data so as to render the data incomprehensible to those 
unauthorized to see the information. See also decryption.
ESMTP
Extended SMTP. Extended version of SMTP that includes additional functionality, such as delivery 
notification and session delivery. ESMTP is described in RFC 1869, SMTP Service Extensions.
ESP
Encapsulating Security Payload. An IPsec protocol, ESP provides authentication and encryption 
services for establishing a secure tunnel over an insecure network. For more information, refer to 
RFCs 2406 and 1827.
F
failover, failover 
mode
Failover lets you configure two adaptive security appliances so that one will take over operation if the 
other one fails. The adaptive security appliance supports two failover configurations, Active/Active 
failover and Active/Standby failover. Each failover configuration has its own method for determining 
and performing failover. With Active/Active failover, both units can pass network traffic. 
Active/Active failover lets you configure load balancing on your network. Active/Active failover is 
only available on units running in multiple context mode. With Active/Standby failover, only one unit 
passes traffic while the other unit waits in a standby state. Active/Standby failover is available on units 
running in either single or multiple context mode.
Fixup
See inspection engine.
Flash, Flash 
memory
A nonvolatile storage device used to store the configuration file when the adaptive security appliance 
is powered down.
FQDN/IP
Fully qualified domain name/IP address. IPsec parameter that identifies peers that are security 
gateways.