Configuration Examples

Example 2: Remote Router Calling the Corporate Network

Figure B-2 shows a network with two BayStack™ AN ® routers at the remote site. The AN routers are using dial-on-demand service for dial-up connections.

In this network, note the following:

PPP is the WAN protocol for the connection between the ISP network and the corporate network.

For the LNS configuration, you do not need to configure a static route for the remote router’s network because the LNS can learn the route using RIP.

The IP network addresses are assigned as follows:

jsmart@bay.com: 192.32.40.1

mmark@bay.com: 192.32.40.2

PC

PC

No active call from mmark; no tunnel needed

mmark@bay.com

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

No L2TP

 

 

 

 

 

 

Modem

 

 

functionality

 

 

jsmart@bay.com

 

 

 

 

 

 

 

 

 

 

 

No L2TP

 

 

 

TA

Multilink

 

 

 

 

 

 

 

 

functionality

 

ISDN PPP

ISP network

LAC 2

TMS

LAC 1

PPP

Tunnel

Corporate

network

Router

LNS

192.32.16.55

.26.0

 

.17

192.32.40.254

L2TP IP RADIUS server

interface 192.32.26.6 bay_private

Domain name in TMS database bay.com = 192.32.16.55

IP addresses in the

RADIUS server database

192.32.40.1 jsmart@bay.com 192.32.40.2 mmark@bay.com

L2T0008B

Figure B-2. L2TP Network with Routers at the Remote Site

The LNS configuration in this example is the same as in Example 1; however, you must modify the configuration of the remote AN router. Go to the next sections.

303532-A Rev 00

B-5

Page 75
Image 75
Nortel Networks L2TP manual Example 2 Remote Router Calling the Corporate Network

L2TP specifications

Nortel Networks L2TP, or Layer 2 Tunneling Protocol, is a widely recognized networking protocol that enables the tunneling of data over various networks. Initially developed as an extension of the Point-to-Point Tunneling Protocol (PPTP), L2TP integrates components from both PPTP and Layer 2 Forwarding (L2F). Nortel Networks played a significant role in the development and implementation of L2TP, making it a prominent choice for service providers and enterprise networks seeking secure and efficient connectivity.

One of the primary features of L2TP is its ability to encapsulate data packets, allowing the transport of PPP (Point-to-Point Protocol) frames without necessitating the traditional point-to-point connections. This means L2TP can operate across different networks, facilitating remote access connections and VPNs (Virtual Private Networks). As a result, organizations can achieve greater flexibility in managing their communications infrastructure.

Another key characteristic of L2TP is its support for both IPv4 and IPv6, ensuring compatibility with current and future networking environments. L2TP operates at the link layer of the OSI model, which means it functions between the data link and network layers, making it versatile for various applications. By using UDP (User Datagram Protocol) as a transport protocol, L2TP ensures efficient data transmission while maintaining lower latencies.

Security is a critical aspect of L2TP. While L2TP itself does not provide encryption, it is often paired with IPSec (Internet Protocol Security) for enhanced security protocols. This combination offers both tunneling and encryption, creating a secure framework for transmitting sensitive information across potentially insecure networks, such as the Internet.

L2TP also features various authentication methods, allowing for robust access control. It supports various schemes like PAP (Password Authentication Protocol) and CHAP (Challenge Handshake Authentication Protocol), giving network administrators a range of options to ensure the legitimacy of users accessing the network.

In summary, Nortel Networks L2TP is a powerful tunneling protocol known for its flexibility, compatibility, and security features. Its ability to encapsulate data for efficient transport makes it ideal for remote access and VPN applications. As organizations continue to demand secure, seamless connectivity, L2TP remains a resilient choice within the shifting landscape of networking technologies.