ADD PPP Command in PPP Configuration

Introduction

PPP (Point-to-Point Protocol) is a network protocol that allows communication between two devices over a point-to-point connection. It is a widely used protocol for establishing and managing Internet connections over dial-up, DSL, and other types of connections.

PPP uses a variety of commands to configure and manage communication session between two devices. One such command is "ADD PPP" command. In this article, we will discuss ADD PPP command in PPP configuration, its significance, and various examples of its usage.

What is ADD PPP Command?

The ADD PPP command is a configuration command used to create a new PPP session on a device. It is typically used in situations where multiple PPP sessions are required on a device, such as in a network environment where multiple users need to connect to Internet simultaneously.

When ADD PPP command is executed, it creates a new PPP session with specified configuration parameters. These parameters include authentication method, IP address, subnet mask, and other settings that are necessary for PPP session to function properly.

The ADD PPP command can be used in conjunction with other PPP configuration commands to configure a complete PPP session. following sections describe some of parameters that can be configured using ADD PPP command.

Examples of ADD PPP Command Usage

Adding a PPP Session with PAP Authentication

Suppose we want to add a new PPP session to our device with PAP (Password Authentication Protocol) authentication. We can use following command −

ADD PPP USER=USERNAME PASSWORD=PASSWORD AUTH=PAP

In this command, "USERNAME" is user's username, and "PASSWORD" is user's password. "AUTH" parameter specifies authentication method to use, which in this case is PAP.

Adding a PPP Session with CHAP Authentication

Suppose we want to add a new PPP session to our device with CHAP (Challenge-Handshake Authentication Protocol) authentication. We can use following command −

ADD PPP USER=USERNAME PASSWORD=PASSWORD AUTH=CHAP

In this command, "USERNAME" is user's username, and "PASSWORD" is user's password. "AUTH" parameter specifies authentication method to use, which in this case is CHAP.

Adding a PPP Session with Static IP Address

Suppose we want to add a new PPP session to our device with a static IP address. We can use following command −

ADD PPP USER=USERNAME PASSWORD=PASSWORD AUTH=PAP IP=192.168.0.2 MASK=255.255.255.0

In this command, "USERNAME" is user's username, and "PASSWORD" is user's password. "AUTH" parameter specifies authentication method to use, which in this case is PAP. "IP" parameter specifies static IP address to assign to PPP session, and "MASK" parameter specifies subnet mask to use.

Adding a PPP Session with Dynamic IP Address

Suppose we want to add a new PPP session to our device with a dynamic IP address. We can use following command −

ADD PPP USER=USERNAME PASSWORD=PASSWORD AUTH=PAP IP=0.0.0.0

In this command, "USERNAME" is user's username, and "PASSWORD" is user's password. "AUTH" parameter specifies authentication method to use, which in this case is PAP. "IP" parameter specifies that a dynamic IP address should be assigned to PPP session.

Benefits of Using ADD PPP Command

The ADD PPP command has several benefits, including −

Multiple Users can connect to Internet

One of significant benefits of using ADD PPP command is that it allows multiple users to connect to Internet simultaneously. This feature is especially important in network environments where multiple users need to access Internet at same time.

Easy Configuration

ADD PPP command makes it easy to configure a new PPP session on a device. With just a few simple commands, a new PPP session can be created with required configuration parameters.

Secure Connection

ADD PPP command supports various authentication methods such as PAP, CHAP, and MS-CHAP, which can help to ensure that connection between two devices is secure.

Flexible IP Address Assignment

ADD PPP command allows for flexible IP address assignment, which can be either static or dynamic. This flexibility enables network administrators to assign IP addresses as per their network requirements.

Easy to Troubleshoot

ADD PPP command makes it easy to troubleshoot PPP connection issues. If a connection is not working correctly, administrator can use ADD PPP command to check configuration parameters and make any necessary changes.

Common Errors when using ADD PPP Command

While using ADD PPP command, there are some common errors that network administrators should be aware of, including −

Incorrect Authentication Method

authentication method specified in ADD PPP command must match authentication method used by remote device. If authentication method is incorrect, PPP session will not be established.

IP Address Conflicts

If two devices on same network have same IP address, a conflict can occur, and PPP session will not be established. To avoid this issue, ensure that IP address assigned to PPP session is unique.

Incorrect Subnet Mask

subnet mask specified in ADD PPP command must be correct; otherwise, PPP session will not be established. Ensure that subnet mask is configured correctly to avoid any connection issues.

Incorrect User Credentials

username and password specified in ADD PPP command must be correct. If credentials are incorrect, PPP session will not be established.

Example Scenarios of ADD PPP Command Usage

Let us now discuss some examples of how ADD PPP command can be used in various scenarios −

Scenario 1: PPP Session between a Router and a Modem

Suppose you have a router that needs to connect to a modem via PPP. You can use ADD PPP command to configure PPP session. following are steps to configure PPP session −

• Configure router interface that connects to modem.

Router(config)# interface serial 0/0/0 
Router(config-if)# encapsulation ppp 
Router(config-if)# no ip address 
Router(config-if)# ppp authentication chap

• Configure ADD PPP command to create PPP session.

Router(config)# interface dialer 1 
Router(config-if)# ip address negotiated 
Router(config-if)# encapsulation ppp 
Router(config-if)# dialer pool 1 
Router(config-if)# ppp chap hostname modem 
Router(config-if)# ppp chap password cisco

In above configuration, dialer 1 interface is configured to create PPP session. IP address is negotiated with remote device, and encapsulation is set to PPP. dialer pool command specifies pool of virtual access interfaces that router can use for this session. Finally, ppp chap hostname and ppp chap password commands specify username and password used for CHAP authentication.

Scenario 2: Multiple PPP Sessions on a Router

Suppose you have a router that needs to establish multiple PPP sessions with different remote devices. You can use ADD PPP command to configure multiple PPP sessions on router. following are steps to configure multiple PPP sessions:

• Configure router interface that connects to each remote device.

Router(config)# interface serial 0/0/0 
Router(config-if)# encapsulation ppp 
Router(config-if)# no ip address

• Configure ADD PPP command to create PPP session for each remote device

Router(config)# interface dialer 1 
Router(config-if)# ip address negotiated 
Router(config-if)# encapsulation ppp 
Router(config-if)# dialer pool 1 
Router(config-if)# ppp chap hostname modem1 
Router(config-if)# ppp chap password cisco1

Router(config)# interface dialer 2 
Router(config-if)# ip address negotiated 
Router(config-if)# encapsulation ppp 
Router(config-if)# dialer pool 2 
Router(config-if)# ppp chap hostname modem2 
Router(config-if)# ppp chap password cisco2

In above configuration, two dialer interfaces are configured to create two PPP sessions. IP address is negotiated with remote device, and encapsulation is set to PPP. dialer pool command specifies pool of virtual access interfaces that router can use for each session. Finally, ppp chap hostname and ppp chap password commands specify username and password used for CHAP authentication for each session.

Conclusion

In summary, ADD PPP command is a configuration command used to create a new PPP session on a device. It is typically used in situations where multiple PPP sessions are required on a device, such as in a network environment where multiple users need to connect to Internet simultaneously.

The ADD PPP command can be used to configure various parameters of PPP session, such as authentication method, IP address, subnet mask, and other settings. By using ADD PPP command in combination with other PPP configuration commands, a complete PPP session can be configured.

Overall, ADD PPP command is a crucial command in PPP configuration, as it allows for creation of multiple PPP sessions on a device, enabling multiple users to connect to Internet simultaneously. Therefore, it is essential to have a good understanding of ADD PPP command and its usage in PPP configuration.