Red Hat Linux 7.2 Bible, Unlimited ed phần 7 potx

The Ethereal Capture window displays information on how many incoming and outgoing packets have crossed the interface since the capture began. The number of packets that are associated with each protocol Ethereal monitors is displayed, along with the percentage of total packets associated with each protocol. For this example, I opened a Web page (resulting in TCP packets) and ran the ping command (resulting in ICMP packets). Figure 15−11: Ethernet activity is displayed by protocol as packets are captured. 6. Click Stop. The snapshot of data you just took will appear on the Ethereal window. Packets are displayed in the order in which they traversed the interface. 7. If you did not already ask to save the capture data to a file, you may do so now by choosing File → Save As. At this point, you can start interpreting the data. Using Ethereal Filters If you are monitoring a busy server or a busy network, Ethereal can gather so much data that it can become almost unusable. If you know what you are looking for, however, you can use Ethereal to filter what packets are captured based on values you enter. Filters in Ethereal are implemented using the pcap library (type man pcap to read about it). The filter expressions you can use with Ethereal are described on the tcpdump man page. Here are some examples of filters that you could enter into the Filter box when you capture Ethernet data with Ethereal: host 10.0.0.15 The host primitive lets you only capture packets that are either to or from a particular host computer (by IP address or host name). By preceding host with src or des, you can indicate that you only want packages sent from a particular source or to a particular destination host. tcp port 80 You can enter a protocol name (such as tcp, ether, udp, or ip) to limit captured packets to those that are assigned to that protocol. As shown in the previous example, with tcp you could also indicate a port number (such as 80, to monitor traffic to and from your Web server). You can filter for certain special activities on the network, using such things as the gateway, broadcast, or multicast primitives. Entering gateway host lets you find packets sent to a gateway host that is neither a Source nor Destination for the packet (which is determined because the Ethernet address doesn't match either of those IP addresses). Enter ether broadcast to monitor broadcast packets on your Ethernet network, such as announcements from name servers announcing availability. Likewise, you could filter for multicast packets on ether or ip protocols (ether multicast). Interpreting captured Ethernet data With the captured data displayed in your Ethereal window, you can get a detailed view of the network traffic that your computer is exposed to. The Ethereal window is divided into three parts. The top part contains a scrollable list of packets. The protocol tree for the current packet appears in the middle part of the display. A hexadecimal dump of the entire contents of the packet appears in the bottom part. You can sort data in different ways from the top part of the window by clicking on the column headings. To see more details relating to different items in the protocol tree for the current packet, you can click the plus sign next to the protocol information that interests you. The following are some tips that will help you interpret what the data means: • The Source and Destination columns show where each packet came from and where it went. If the Enable name resolution option is on (which is recommended), the host name associated with IP packets is displayed. This makes it much easier to see which computer is communicating with you. • To see all activity associated with a particular location, click the Source or Destination column. Packets will be sorted alphabetically, making it easier for you to scroll through activity for the location that interests you. • If you are trying to debug a particular feature, you may want to click the Protocol column to gather activities based on protocol. For example, if you were trying to get Samba to work (for Windows file or printer sharing), sorting by protocol would enable you to see all NetBIOS and NBNS (NetBIOS name server) requests that came to your computer. • To mark a packet of interest to you, click the middle mouse button on it. This will highlight the packet, making it easier to find later. (If you only have a two−button mouse, and you indicated during installation that it should emulate a three−button mouse, you can click both mouse buttons together to emulate the middle mouse button.) The Info column gives you details about the intention of the packet. For example, you can see the type of service that was requested (such as http for Web service or FTP for file transfer). You can see what information is being broadcast and determine when attempts to find particular host computers are failing. If you believe someone is using your network improperly, you can see which sites they are visiting and the services they are requesting. Another handy option is one that lets you follow the stream of TCP information. Click Tools → Follow TCP Stream. The "Contents of TCP stream" window that appears lets you see the total output of the HTTP, SMTP, or other protocol being used. Summary Red Hat Linux is at its best when it is connected to a network. Configuring a LAN enables you to share resources with other computers in your home or organization. These resources can include files, printers, CD−ROM drives, and backup media. This chapter describes how to create a LAN with a Red Hat Linux system being used on one of the computers on that LAN. It helps you determine the kind of equipment you need to obtain, and the layout (topology) of the network. On the Red Hat Linux side, you learned about choosing and installing Ethernet cards (also called NICs). You also learned to configure TCP/IP so that you can later employ a variety of TCP/IP tools to use the network. If something isn’t working with your Red Hat Linux interface to the LAN, you can use utilities such as ifconfig to check that your Ethernet interface is configured and running properly. You can also check that Linux found and installed the proper driver for your Ethernet card. After an Ethernet interface is working, you can use the Ethereal window to monitor the packets coming and going across the interface between your computer and the network. Chapter 16: Connecting to the Internet Overview This chapter demonstrates how to connect Red Hat Linux to any TCP/IP−based network, such as the Internet, a private intranet, or a company extranet. The differences in how you connect have more to do with the network medium you use (that is, telephone lines, LAN router, and so on) than they do with whether you are connecting to the public Internet or a company’s private network. Connections to the Internet described in this chapter include a simple dial−up connection from your own Red Hat Linux system. The most popular protocols for making dial−up connections to the Internet are Point−to−Point Protocol (PPP) and Serial Line Internet Protocol (SLIP). This chapter focuses on PPP (it is more widely used than SLIP). It also builds on the procedures in Chapter 15 for creating your own Local Area Network (LAN) by teaching you how to connect your LAN to the Internet. This chapter first provides an overview of the structure of the Internet, including descriptions of domains, routing, and proxy service. It then discusses how to connect your Red Hat Linux system to the Internet using PPP dial−up connections. For those who want to connect a LAN to the Internet, it describes how to use Red Hat Linux as a router and set it up to do IP masquerading (to protect your private LAN addresses). Finally, it describes how to configure Red Hat Linux as a proxy server, including how to configure client proxy applications such as Netscape and Microsoft Internet Explorer. Understanding How the Internet Is Structured In order to operate, the Internet relies on maintaining a unique set of names and numbers. The names are domain names and hostnames, which enable the computers connected to the Internet to be identified in a hierarchy. The numbers are Internet Protocol (IP) addresses and port numbers, which enable computers to be grouped together into interconnected sets of subnetworks, yet remain uniquely addressable by the Internet. An Internet Service Provider (ISP) will give you the information you need to set up a connection to the Internet. You plug that information into the programs used to create that connection, such as scripts to create a Point−to−Point Protocol (PPP) connection over telephone lines. See the section later in this chapter on outgoing dial−up connections for descriptions of the information needed from your ISP and the procedures for configuring PPP to connect to the Internet. The following list describes basic Internet structure in more detail: • IP addresses — These are the numbers that uniquely define each computer known to the Internet. Internet authorities assign pools of IP addresses (along with network masks, or netmasks) so that network administrators can assign addresses to each individual computer that they control. An alternative to assigned addresses is to use a reserved set of private IP addresses. Cross−Reference See Chapter 15 for a description of IP addresses. • Port numbers — Port numbers provide access points to particular services. A server computer will listen on the network for packets that are addressed to its IP address, along with one or more port numbers. For example, a Web server listens to port 80 to respond to requests for HTTP content. • Domain names — On the Internet, computer names are organized in a hierarchy of domain names and hostnames. If you want to have and maintain your own Internet domain, you need to be assigned one that fits into one of the top−level domains (domains such as .com, .org, .net, .edu, .us, and so on). • Hostnames — If a domain name is assigned to your organization, you are free to create your own hostnames within that domain. This is a way of associating a name (hostname) with an address (IP address). When you use the Internet, you use a fully qualified domain name to identify a host computer. For example, in the domain handsonhistory.com, a host computer named baskets would have a fully qualified domain name of baskets.handsonhistory.com. Within an organization, you should choose a host−naming scheme that makes sense to you. For example, for handsonhistory.com, you could have hostnames dedicated to different crafts (baskets, decoys, weaving, and so on). • Routers— If you have a LAN or other type of network in your home or organization that you want to connect to the Internet, you can share an Internet connection. You do this by setting up a router. The router connects to both your network and the Internet, providing a route for data to pass between your network and the Internet. • Firewalls and IP masquerading — To keep your private network somewhat secure, yet still allow some data to pass between it and the Internet, you can set up a firewall. The firewall restricts the kind of data packets or services that can pass through the boundary between the private and public networks. If your network uses private addresses, or if you just want to protect the addresses of computers behind your firewall, you can use a technique called IP masquerading. Note Though you can set up a firewall to filter packets on any computer on your private network, firewalls are typically configured on the machine that routes packets between the public and private networks. In this way, intruders can be stopped before they get on your private network and security can be relaxed somewhat between your computers behind the firewall. • Proxies — You can bypass some of the configuration required to allow the computers on your LAN to communicate directly with the Internet by configuring a proxy server. With a proxy server, a computer on your LAN can run Internet applications (such as a Web browser) and have them appear to the Internet as if they are actually running on the proxy server. Cross−Reference You can read about firewalls in Chapter 14. IP masquerading is described later in this chapter. Internet domains You can’t read a magazine, watch a TV commercial, or open a cereal box these days without hitting a “something.com.” When a company, organization, or person wants you to connect to them on the Internet, it relies on the uniqueness of its particular domain name. However, within that domain name, the company or organization to which it has been assigned can arrange its content however it chooses. Internet domains are organized in a structure called the domain name system (DNS). At the top of that structure is a set of top−level domains (or TLDs). Some of the top−level domains are used commonly in the United States, although they are available for worldwide use. TLDs such as edu (for colleges and universities), gov (for United States government), and mil (for United States military sites) were among the most used TLDs in the early Internet. In more recent years, com (for commercial sites) has experienced the most growth. The us domain was added to include U.S. institutions, such as local governments and elementary schools, as well as to individuals within a geographical region of the United States. To facilitate the entry of other countries to the Internet, the International Organization for Standardization (ISO) has defined a set of two−letter codes that are assigned to each country. Within each country, there are naming authorities that are responsible for organizing the subdomains. Some subdomains are organized by categories, while others are structured by geographic location. Tip Several RFCs (Request for Comments) define the domain name system. RFC 1034 covers domain name concepts and facilities. RFC 1035 is a technical description of how DNS works. RFC 1480 describes the "us" domain. For a more general description of DNS, there is RFC 1591. Common top−level domain names Of the generic TLDs in use today, several are used throughout the world, while two are available only in the United States. Here are descriptions of common TLDs: • com — Businesses, corporations, and other commercial organizations fall into this TLD. As the Internet has grown into an important tool for commerce, domains in this TLD have grown at a dramatic rate. • edu — Colleges and universities fall under this TLD. Although it was originally intended for all educational institutions, two−year colleges, high schools, and elementary schools are now organized by location under country codes (such as US in the United States). • gov — This TLD is restricted to U.S. federal government locations. Local government sites are expected to fall under the us domain. • int — This domain includes international databases and organizations created by international treaties. • mil — U.S. military organizations fall under this domain. • net — Computer network providers fall under this domain. • org — A variety of organizations that are neither governmental nor commercial in nature fall under this catchall TLD. Domain name formation As noted earlier, domain names are hierarchical, which means there can be subdomains beneath second−level domains, as well as host computers. (Second−level domains are the names directly below the TLDs that are assigned to individual people and organizations.) Each subdomain is separated by a dot (.), starting with the top−level domain on the right and with the second−level domain and each subsequent subdomain appearing to the left. Here is an example of a fully qualified domain name for a host: baskets.crafts.handsonhistory.com In this example, the top−level domain is .com. The second−level domain name assigned to the organization that controls the domain is handsonhistory. Within that domain is a subdomain called crafts. The last name (baskets) refers to a particular computer within that second−level domain. From other hosts in the second−level domain, the host can be referred to simply as baskets. From the Internet, you would refer to it as baskets.crafts.handsonhistory.com. Hostnames and IP addresses In the early days of the Internet, every known host computer name and address was collected into a file called HOSTS.TXT and distributed throughout the Internet. This quickly became cumbersome because of the size of the list and the constant changes being made to it. The solution was to distribute the responsibility for resolving hostnames and addresses to many DNS servers throughout the Internet. To make the domain names friendly, the names contain no network addresses, routes, or other information needed to deliver messages. Instead, each computer must rely on some method to translate domain names and hostnames into IP addresses. The DNS server is the primary method of resolving the names to addresses. If you request a service from a computer using a fully qualified domain name (including all domains and subdomains), it will go to the DNS server to resolve that name into an IP address. If you have a private LAN or other network, you can keep your own list of hostnames and IP addresses. For the computers you work with all the time, it’s easier to type baskets than baskets.crafts.handsonhistory.com. There are a couple of ways (besides DNS) that your computer can resolve the IP address for computers for which you give only the hostname: • Check the /etc/hosts file. In your computer’s /etc/hosts file, you can place the names and IP addresses for the computers on your local network. In this way, your computer doesn’t need to query the DNS server to get the address (which may not be there anyway if you are on a private network). • Check specified domains. You can specify that if the hostname requested doesn’t include a fully qualified domain name and the hostname is not in your /etc/hosts file, then your computer should check certain specified domain names. On your Red Hat Linux system, the decisions on how to try to resolve hostnames to IP addresses are taken from the /etc/resolv.conf file. That file specifies your local domain, an alternative list of domains, and the location of one or more DNS servers. Here is an example of an /etc/resolv.conf file: domain crafts.handsonhistory.com search crafts.handsonhistory.com handsonhistory.com nameserver 10.0.0.10 nameserver 10.0.0.12 In this example, the local domain is crafts.handsonhistory.com. If you try to contact a host by giving only its hostname (with no domain name), your computer can check in both crafts.handsonhistory.com and handsonhistory.com domains to find the host. If you give the fully qualified domain name, it can contact the name servers (first 10.0.0.10 and then 10.0.0.12) to resolve the address. (You can specify up to three name servers that your computer will query in order until the address is resolved.) Tip Your resolver knows to check your /etc/hosts file first because of the contents of the /etc/host.conf and /etc/nsswitch files. You can change that behavior by modifying those files. See the resolv.conf man page for further information. Routing Knowing the IP address of the computer you want to reach is one thing; being able to reach that IP address is another. Even if you connect your computers on a LAN, to have full connectivity to the Internet there must be at least one node (that is, a computer or dedicated device) through which you can route messages that are destined for locations outside your LAN. That is the job of a router. A router is a device that has interfaces to at least two networks and is able to route network traffic between the two networks. In our example of a small business that has a LAN that it wants to connect to the Internet, the router would have a connection and IP address on the LAN, as well as a connection and IP address to a network that provides access to the Internet. Red Hat Linux can act as a router by connecting to two LANs or by connecting to a LAN and a modem (to dial−up the Internet). Alternatively, you can purchase a dedicated router, such as Cisco ADSL routers, that can exclusively perform routing between your LAN and the Internet or network service provider. Tip Unlike regular dial−up modems, xDSL modems have several different standards that are not all compatible. Before purchasing a xDSL modem, check with your ISP. If your ISP supports xDSL, it can tell you the exact models of xDSL modems you can use to get xDSL service. Proxies Instead of having direct access to the Internet (as you do with routing), you can have indirect access via the computers on your LAN by setting up a proxy server. With a proxy server, you don’t have to configure and secure every computer on the LAN for Internet access. When, for example, a client computer tries to access the Internet from a Web browser, the request goes to the proxy server. The proxy server then makes that request to the Internet. Using a proxy server, Internet access is fairly easy to set up and quite secure to use. Red Hat Linux can be configured as a proxy server (as described later in this chapter). Using Dial−up Connections to the Internet Most individuals and even many small businesses that need to connect to the Internet do so using modems and telephone lines. Your modem connects to a serial port (COM1, COM2, and so on) on your computer and then into a telephone wall jack. Then your computer dials a modem at your Internet Service Provider or business that has a connection to the Internet. The two most common protocols for making dial−up connections to the Internet (or other TCP/IP network) are Point−to−Point Protocol (PPP) and Serial Line Internet Protocol (SLIP). Of the two, PPP is more popular and more reliable. SLIP, however, has been around longer. This section describes how to use PPP protocol to connect to the Internet. Getting information To establish a PPP connection, you need to get some information from the administrator of the network that you are connecting to. This is either your Internet Service Provider (ISP) when you sign up for Internet service or the person who walks around carrying cables, a cellular phone, and a beeper where you work (when a network goes down, these people are in demand!). Here is the kind of information you need to set up your PPP connection: • PPP or SLIP — Does the ISP require SLIP or PPP protocols to connect to it? In this book, I describe how to configure PPP. • Telephone number — This telephone number gives you access to the modem (or pool of modems) at the ISP. If it is a national ISP, make sure that you get a local telephone number (otherwise, you will rack up long distance fees on top of your ISP fees). • Account name and password — This information is used to verify that you have an Internet account with the ISP. This is typically used when you connect to Red Hat Linux or other UNIX system. (When connecting to an NT server, the account name may be referred to as a system name.) • An IP number — Most ISPs use Dynamic IP numbers, which means that you are assigned an IP number temporarily when you are connected. Your ISP assigns a permanent IP number if it uses Static IP addresses. If your computer or all the computers on your LAN need to have a more permanent presence on the network, you may be given one Static IP number or a set of Static IP numbers to use. • DNS IP numbers — When you use a Web browser, FTP utility, or other Internet program to request a service from a computer on the network, you need a way to translate that name (for example, whatever.com) into an Internet address. Your computer will do this by querying a Domain Name System (DNS) server. Your ISP should give you at least one, and possibly two or three, IP addresses for a primary (and possibly secondary and tertiary) DNS server. • PAP or CHAP secrets — You may need a PAP id or CHAP id and a secret, instead of a login and password when connecting to a Windows NT system. These features are used with authentication on Microsoft operating systems, as well as other systems. Red Hat Linux and other UNIX servers don’t typically use this type of authentication, although they support PAP and CHAP on the client side. If Red Hat Linux didn’t support PAP or CHAP, you wouldn’t be able to connect to a great many ISPs. Besides providing an Internet connection, your ISP typically also provides services for use with your Internet connection. Although you don’t need this information to create your connection, you will need it soon afterward to configure these useful services. Here is some information you should acquire: • Mail server — If your ISP is providing you with an e−mail account, you need to know the address of the mail server, the type of mail service (such as Post Office Protocol or POP), and the authentication password for the mail server in order to get your e−mail. • News server — To be able to participate in newsgroups, the ISP may provide you with the hostname of a news server. If the server requires you to log on, you will also need a password. After you have gathered this information, you are ready to set up your connection to the Internet. To configure Red Hat Linux to connect to your ISP, follow the PPP procedure described below. Setting up dial−up PPP Point−to−Point Protocol (PPP) is used to create Internet Protocol (IP) connections over serial lines. Most often, the serial connection is established over a modem; however, it will also work over serial cables (null modem cables) or digital lines (including ISDN and DSL digital media). PPP is a common way to connect an individual computer or LAN to a TCP/IP Wide Area Network (such as the Internet). Although one side must dial out while the other side must receive the call to create a PPP connection over a modem, after the connection is established, information can flow in both directions. For the sake of clarity, however, I refer to the computer placing the call as the client and the computer receiving the call as the server. To simplify the process of configuring PPP (and other network interfaces), Red Hat Linux provides a dial−up configuration tool for both the GNOME and KDE interfaces. Those interfaces are, respectively, as follows: • Dialup Configuration Tool — From the GNOME desktop menu, choose Programs → Internet → Dialup Configuration. The Internet Connection window that appears lets you configure and test your dial−up PPP connection. • Kppp Window — From the KDE desktop menu, choose Internet → Internet Dialer. This runs the kppp command. From the kppp window you can set up a PPP dial−up connection and launch it. Before you begin either of the two dial−up procedures, physically connect your modem to your computer, plug it in, and connect it to your telephone line. If you have an internal modem, you will probably see a telephone port on the back of your computer that you need to connect. After the modem is connected, reboot Red Hat Linux so it can automatically detect and configure your modem. Creating a dial−up connection from GNOME To configure dial−up networking from the GNOME desktop, you should use the Dialup Configuration window. To start it, choose Programs → Internet → Dialup Configuration from the GNOME menu. A connection wizard appears to help you configure your PPP dial−up connection, as shown in Figure 16−1. Figure 16−1: The Dialup Configuration Tool steps you through a PPP Internet connection. Follow the procedure below from the first Dialup Configuration Tool window to configure your dial−up connection. 1. From the Add New Internet Connection window that appears, click Next to continue. If you do not have a modem configured, you are asked if you want to configure one. 2. Click Next to configure a modem. A pop−up window searches your computer for a modem. If it finds your modem, its location will be filled in on the Enter a modem window. Otherwise, you will have to enter the location of the modem yourself. 3. [...]... 20:44:10 20:44:10 20:44:14 20:44:14 20:44:14 6 20:44: 17 6 20:44: 17 maple maple maple maple maple maple maple maple maple maple maple maple maple maple maple maple chat[2 079 ]: chat[2 079 ]: chat[2 079 ]: chat[2 079 ]: chat[2 079 ]: chat[2 079 ]: chat[2 079 ]: chat[2 079 ]: chat[2 079 ]: chat[2 079 ]: chat[2 079 ]: chat[2 079 ]: chat[2 079 ]: pppd[2 077 ]: pppd[2 077 ]: pppd[2 077 ]: abort on (Login incorrect) send (ATZ^M) expect (OK)... the Internet may be a dial−up PPP connection or a higher−speed DSL or cable modem connection • Packets on the LAN that are not addressed to a known computer on the LAN are forwarded to the router (that is, the Red Hat Linux system acting as a router) So, each client identifies that Red Hat Linux system as the gateway system • The Red Hat Linux "router" firewall is set up to receive packets from the... the Red Hat Linux router, as well as the client computers from your LAN (Red Hat Linux and MS Windows clients) that will use this router Using Red Hat Linux as a router also provides an excellent opportunity to improve the security of your Internet connection by setting up a firewall to filter traffic and hide the identity of the computers on your LAN (IP masquerading) Configuring the Red Hat Linux. .. is the computer that is configured to access the printer (with the printer often physically attached) Printing in Red Hat Linux Beginning with Red Hat Linux 7, printing is provided by the LPRng (LPR Next Generation) print spooling system The LPRng software offers many security benefits over the old LPR print spooling facility that was originally used with UNIX systems LPRng is based on the old Berkeley... printer features, such as high−speed printing or color You can attach printers to your Red Hat Linux system to make them available to users of that system or to other computers on the network You can configure your Red Hat Linux printer as a remote Linux printer, a Samba printer, or a NetWare printer With Samba and NetWare, you are emulating those types of servers Red Hat Linux can also act as a client,... 20:43:52 20:43:52 20:43:52 20:43:52 20:43:52 maple maple maple maple maple maple maple pppd[2 077 ]: pppd 2.3 .7 started by root, uid 0 ifup−ppp: pppd started for ppp0 on /dev/modem at 115200 chat[2 079 ]: abort on (BUSY) chat[2 079 ]: abort on (ERROR) chat[2 079 ]: abort on (NO CARRIER) chat[2 079 ]: abort on (NO DIALTONE) chat[2 079 ]: abort on (Invalid Login) Jun Jun Jun Jun Jun Jun Jun Jun Jun Jun Jun Jun Jun Jun Jun... (as described in Chapter 23) • Valid IP addresses — If your LAN uses addresses that were officially assigned by your ISP or other registration authority, you don’t need to do any special IP masquerading With your Red Hat Linux computer’s LAN and Internet interfaces in place, follow the procedure below to set up Red Hat Linux as a router: 1 Open the /etc/sysconfig/network file in a text editor as the... possibilities for your Red Hat Linux computer Using Red Hat Linux as a Web server, mail server, or FTP server depends on Red Hat Linux s capability to connect to the Internet Likewise, if your computers are already connected together in a LAN, adding an Internet connection can provide Internet access to everyone on the LAN in one stroke Descriptions of how Internet domains are organized built on discussions... The output shows that the forwarding policy (forward) is set to do masquerading (MASQ) for computers on the network 10.0.0.0 At this point, you should set up the client computers to use your Red Hat Linux router for their Internet connections Configuring network clients In this example, there are a variety of Red Hat Linux and Windows operating system clients on a LAN One Red Hat Linux computer has... 6 Click OK 7 You may need to reboot your computer at this point, if Windows requires you to do so At this point, try accessing a Web site from your Internet browser on the Windows computer If the Internet connection is up on your Red Hat Linux computer, you should be able to connect to the Internet through your LAN connection to the Red Hat Linux computer Setting Up Red Hat Linux as a Proxy Server . 20 :43:53 maple chat [2 079 ]: ^M Jun 6 20 :44:10 maple chat [2 079 ]: ATDT555 121 2^M^M Jun 6 20 :44:10 maple chat [2 079 ]: CONNECT Jun 6 20 :44:10 maple chat [2 079 ]: −− got it Jun 6 20 :44:10 maple chat [2 079 ]: send. (BUSY) Jun 6 20 :43: 52 maple chat [2 079 ]: abort on (ERROR) Jun 6 20 :43: 52 maple chat [2 079 ]: abort on (NO CARRIER) Jun 6 20 :43: 52 maple chat [2 079 ]: abort on (NO DIALTONE) Jun 6 20 :43: 52 maple chat [2 079 ]:. ppp0 <−−> /dev/modem . . . Jun 6 20 :44: 17 maple pppd [2 077 ]: local IP address 22 2. 62. 1 37. 121 Jun 6 20 :44: 17 maple pppd [2 077 ]: remote IP address 22 2. 62. 1.105 This output shows starting the