TMS zl Management and Configuration Guide ST.1.1.100430

B-30

Glossary

static route Routes that are manually added to the routing table.

stub area An area that receives traffic destined for its hosts, but does not pass any traffic

to another network. A stub area connects only with the normal area (back-

bone).

subject alternate

names

Names that you can specify along with a device’s CN that can identify the

device. These names are specified in a certificate request.

SYN flood A DoS attack in which the attacker sends a rapid succession of SYN (synchro-

nize) packets to the targeted system. The attack is intended to disrupt the

normal TCP three-way handshake in which a SYN packet sent by a client is

followed by a SYN-ACK (acknowledge) packet from the server, to which the

client should respond with an ACK packet. When the server does not receive

the ACK packet, its connections remain half-opened, which prevents legiti-

mate clients from making a connection.

syslog A client/server protocol that is used to send log messages from network

devices to a syslog server.

syslog server A server that receives and stores syslog messages from network devices.

TCP Transmission Control Protocol. Part of the IP protocol suite, TCP allows

applications on networked hosts to create connections to one another and

exchange data. TCP guarantees reliable and in-order data delivery. TCP pro-

tocols include, among many others, HTTP, email, and SSH. For more informa-

tion about TCP, see Request for Comments (RFC) 793 (at http://www.ietf.org/

rfc/rfc0793.txt).

threat level One of five, preconfigured categories that indicates the severity of an attack.

The threat levels are Critical, Severe, Minor, Warning, Informational.

timeout The amount of time the firewall will keep a session open without packets being

exchanged.

TLS Transport Security Layer. The successor to SSL, TLS is a protocol that

provides secure communications through encryption and endpoint

authentication.

TMS OS Threat Management Services operating system. The application that pro-

vides threat management services on the zl module.