PPTP - PowerPoint PPT Presentation

Loading...

PPT – PPTP PowerPoint presentation | free to view - id: 11ab62-ZTJmN



Loading


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation
Title:

PPTP

Description:

Distant RAS removes the original packet ... Adds a new IP header with the IP address of the RAS ... Same meaning but different names. NAS. RAS ... – PowerPoint PPT presentation

Number of Views:287
Avg rating:3.0/5.0
Slides: 10
Provided by: WayneS2
Category:
Tags: pptp | ras

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: PPTP


1
PPTP
  • Point-to-Point Tunneling Protocol (PPTP)
  • Problem PPP was created for dialing into a local
    RAS server
  • But the sites RAS may be far away
  • Long-distance calls are expensive

RAS
Long-Distance Call
2
PPTP
  • Point-to-Point Tunneling Protocol (PPTP)
  • We would like PPP to work over the Internet to
    avoid long-distance telephone charges
  • But PPP is only a data link layer protocol
  • It is only good for transmission within a subnet
    (single network)

RAS
3
PPTP
  • The Point-to-Point Tunneling Protocol (PPTP)
    makes this possible
  • Created by Microsoft
  • Widely used

Access Concentrator
RAS
4
PPTP
  • PPTP Operation
  • User dials into local PPTP access concentrator
    host
  • User sends the access concentrator a PPP frame
    within an IP packet

Access Concentrator
RAS
Packet
5
PPTP
  • PPTP Operation
  • Access concentrator places incoming IP packet
    within another IP packet
  • Sends packet to the distant RAS

Access Concentrator
RAS
Encapsulated Packet
6
PPTP
  • PPTP Operation
  • Distant RAS removes the original packet
  • Treats the packet as if it came in over a local
    telephone line
  • Deals with the PPP frame within the packet

RAS
Original IP Packet
7
PPTP
  • PPTP Encapsulation
  • Access concentrator receives the original IP
    packet, which has the destination IP address of
    the access concentrator
  • Adds a new IP header with the IP address of the
    RAS
  • Adds an enhanced general routing encapsulation
    (GRE) header for security

Original IP Packet
Enhanced GRE Header
New IP Header
8
PPTP
  • PPTP Tunneling
  • Encapsulating an IP packet within another packet
    to send it through a network is called tunneling
  • This is how tunneling mode works in IPsec
    (discussed earlier in the module)

RAS
Tunnel
Access Concentrator
9
PPTP
  • Remote Access Server (RAS) is a widely used term
  • PPTP documentation calls them network access
    servers (NASs)
  • Same meaning but different names

NAS
RAS
About PowerShow.com