TMS zl Management and Configuration Guide ST.1.0.090213

B-24
Glossary
ping scan The attacker sends ICMP Echo Request packets, and the host responds with an
ICMP Echo Reply packet if it is active and the firewall does not filter ICMP
packets.
PMTU Path Maximum Transmission Unit. A technique for detecting the maximum
size for an IP packet along a particular path. For more information, see RFC
1191 at http://www.ietf.org/rfc/rfc1191.txt.
poison reverse In RIP, a poison reverse message tells a router that a route in the routing table
is no longer connected. This helps to speed convergence.
policy group A set of policies (firewall or NAT) that have the same source and destination
zones.
polymorphism The capability of an object to assume more than one property, often shifting
from one property to another in response to external stimuli.
port address
translation
See PAT.
port forwarding The process in which traffic addressed to one port is forwarded to a different
port. Port forwarding is often employed when a network is running well-
known protocols on non-standard ports.
port map A port-to-application association that informs the IDS/IPS and ALGs which type
of traffic to expect on a particular port.
port trigger A process that allows the TMS zl Module to dynamically and automatically
forward traffic on particular ports. Port triggers are configured on ports for
applications that require dynamically negotiated ports.
position The position of a policy among other policies. The firewall checks packets
against policies in the order in which they are listed, so a policy with a higher
position (value closer to 1) is checked first.
PR Problem report. Used in the TMS zl Module release notes to describe a known
issue with the module.
pre-connection
ACK
An attack check that the TMS zl Module performs in which the module sends
a RST packet whenever it receives ACK packet without first receiving a SYN
packet.
preshared key See PSK.