166
C
HAPTER
12: C
ONFIGURING
PPP
AND
MP
The authenticator sends some randomly generated packets to the requester
(challenge), and at the same time it sends its configured username to the
requester.
When the requester receives the challenge, it will look for the user password
according to the authenticator's username and its own user list. If it finds the user
in the user list with the same name as the authenticator's username, the requester
builds the response with its own password, serial number of packet using MD5
algorithm, and sends the generated response and its configured username to the
authenticator (response).
After receiving the response from the requester, the authenticator does the same
encryption as the requester with the saved password, serial number of packet
using MD5 algorithm. Then it compares the encryption result with the response
from requester, and returns the response according to the comparison result
(Acknowledge or Not Acknowledge).
3
Phases of PPP negotiation:
a
When the physical layer is unavailable, the link is in Dead phase. A link shall start
from the Dead phase. When the physical layer becomes available, PPP link enters
the Establish phase.
b
In
Establish
phase, PPP link carries out LCP negotiation, including negotiation
of working mode (SP or MP), authentication mode and maximum transmission
unit etc. After the successful LCP negotiation, the status of LCP is
Open
,
indicating that the link has been established.
c
If the authentication is not configured, it begins NCP negotiation. At this time,
the status of LCP is still
Open
, while the status of NCP is changed from
Initial
to
Request-sent
.
d
If the authentication is configured (the remote verifies the local or the local
verifies the remote), it enters
Authenticate
phase to start CHAP or PAP
authentication. If the authentication fails, it enters
Terminate
phase, the link is
removed and LCP turns down. After successful authentication, the NCP
negotiation begins. At this time, the status of LCP is still
Open
, while the status
of NCP is changed from Initial to
Request-sent
.
e
NCP negotiation supports the negotiations of IPCP and IPXCP, of which IPCP
negotiation mainly includes the IP addresses of two partners. One or more
network layer protocols is selected and configured through NCP negotiation.
The selected network layer protocol must be configured successfully before this
network layer protocol sends packets through this link.
f
PPP link will remain in communication status until a specific LCP or NCP frame
closes this link or some external events take place (for example, the
intervention of user).
Phases of PPP negotiation are shown in the following diagram.
Содержание 3036
Страница 1: ...http www 3com com 3Com Router Configuration Guide Published March 2004 Part No 10014299 ...
Страница 4: ...VPN 615 RELIABILITY 665 QOS 681 DIAL UP 721 ...
Страница 6: ...2 ABOUT THIS GUIDE ...
Страница 7: ...I GETTING STARTED Chapter 1 3Com Router Introduction Chapter 2 3Com Router User Interface ...
Страница 8: ...4 ...
Страница 16: ...12 CHAPTER 1 3COM ROUTER INTRODUCTION ...
Страница 34: ...30 ...
Страница 60: ...56 CHAPTER 3 SYSTEM MANAGEMENT ...
Страница 88: ...84 CHAPTER 5 CONFIGURING NETWORK MANAGEMENT RouterA interface ethernet 0 RouterA Ethernet0 rmon promiscuous ...
Страница 98: ...94 CHAPTER 6 DISPLAY AND DEBUGGING TOOLS ...
Страница 110: ...106 ...
Страница 114: ...110 CHAPTER 8 INTERFACE CONFIGURATION OVERVIEW ...
Страница 158: ...154 CHAPTER 10 CONFIGURING WAN INTERFACE ...
Страница 168: ...164 ...
Страница 188: ...184 CHAPTER 13 CONFIGURING PPPOE CLIENT ...
Страница 192: ...188 CHAPTER 14 CONFIGURING SLIP Router ip route static 0 0 0 0 0 0 0 0 10 110 0 1 ...
Страница 248: ...244 CHAPTER 16 CONFIGURING LAPB AND X 25 ...
Страница 292: ...288 CHAPTER 18 CONFIGURING HDLC Enable HDLC packet debugging debugging hdlc packet interface type number ...
Страница 320: ...316 ...
Страница 330: ...326 CHAPTER 20 CONFIGURING IP ADDRESS ...
Страница 362: ...358 CHAPTER 21 CONFIGURING IP APPLICATION ...
Страница 374: ...370 CHAPTER 23 CONFIGURING IP COUNT ...
Страница 406: ...402 CHAPTER 25 CONFIGURING DLSW ...
Страница 408: ...404 ...
Страница 452: ...448 CHAPTER 29 CONFIGURING OSPF ...
Страница 482: ...478 CHAPTER 30 CONFIGURING BGP ...
Страница 494: ...490 CHAPTER 31 CONFIGURING IP ROUTING POLICY ...
Страница 502: ...498 ...
Страница 508: ...504 CHAPTER 33 IP MULTICAST ...
Страница 514: ...510 CHAPTER 34 CONFIGURING IGMP ...
Страница 526: ...522 CHAPTER 36 CONFIGURING PIM SM ...
Страница 528: ...524 ...
Страница 532: ...528 CHAPTER 37 CONFIGURING TERMINAL ACCESS SECURITY ...
Страница 550: ...546 CHAPTER 38 CONFIGURING AAA AND RADIUS PROTOCOL ...
Страница 590: ...586 CHAPTER 40 CONFIGURING IPSEC ...
Страница 599: ...IX VPN Chapter 42 Configuring VPN Chapter 43 Configuring L2TP Chapter 44 Configuring GRE ...
Страница 600: ...596 ...
Страница 638: ...634 CHAPTER 43 CONFIGURING L2TP ...
Страница 649: ...X RELIABILITY Chapter 45 Configuring a Standby Center Chapter 46 Configuring VRRP ...
Страница 650: ...646 ...
Страница 666: ...662 ...
Страница 670: ...666 CHAPTER 47 QOS OVERVIEW ...
Страница 700: ...696 CHAPTER 49 CONGESTION MANAGEMENT ...
Страница 706: ...702 CHAPTER 50 CONGESTION AVOIDANCE ...
Страница 707: ...XII DIAL UP Chapter 51 Configuring DCC Chapter 52 Configuring Modem ...
Страница 708: ...704 ...
Страница 762: ...758 CHAPTER 52 CONFIGURING MODEM ...