Skip to main content

Trust in Cyberspace (1999) / Chapter Skim
Currently Skimming:

Appendix H: Types of Firewalls
Pages 293-295

The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.


From page 293...
... For example, a common security policy allows most outgoing calls but no incoming calls. A packet filter can implement this policy if and only if protocol headers contain fields that differentiate between requests and responses.
Read the entire page →
From page 294...
... Application gateways can handle traffic whose characteristics render packet filters and circuit relays inappropriate enforcement mechanisms. For example, by default the File Transfer Protocol (FTP)
Read the entire page →
From page 295...
... 1988. RPC: Remote Procedure Call Protocol Specification Version 2.
Read the entire page →

Key Terms

  • circuit relays
  • dynamic packet
  • packet filter
  • application gateways
  • remote procedure

  • procedure call
  • transport protocol
  • properly set
  • render packet
  • incoming calls

  • policy allows
  • specification version
  • based solely
  • data transfers
  • protocol specification

  • mediate access
  • application programs
  • transport layer
  • sun microsystems
  • include source

  • protocol semantics
  • inappropriate enforcement
  • characteristics render
  • relays unsuitable
  • handle traffic

  • inbound channel
  • source address
  • relays inappropriate
  • destination addresses
  • enforcement mechanisms


    • This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
    More information on Chapter Skim is available.