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Appendix D     Glossary

Snort Rule A way of conveying intruder signatures to Snort.

TOS

Type of Service field used in IPv4 packet header.

Trust Levels Different levels of trust may be imposed in different trust zones (see

Trust Zone). For example, a financial database may be at a different trust level than a

company public web server.

Trust Zone An area of your network where you apply the same security policy. For

example, all publicly accessible hosts (WWW and e mail servers) may be placed in a

demilitarized zone (DMZ).

TTL Time to Live field used in IP packet header.