blob: f0d71856378ea56458f5cbb5f95f4f3029677d37
| 1 | # LIC: GPL |
| 2 | |
| 3 | $Id$ |
| 4 | |
| 5 | This package lets you connect a Linux machine to an ISP that uses PPPoE. |
| 6 | PPPoE is used by many DSL providers and some wireless providers. |
| 7 | |
| 8 | Follow these steps and you should have your PPPoE service up and running. |
| 9 | |
| 10 | 0. Install the rp-pppoe-software |
| 11 | -------------------------------- |
| 12 | |
| 13 | You should have already done this by the time you're reading this. If not, |
| 14 | go back and read README. |
| 15 | |
| 16 | 1. Set up your Ethernet hardware |
| 17 | -------------------------------- |
| 18 | |
| 19 | First, make sure the Ethernet card you intend to use with the modem is |
| 20 | visible to the Linux kernel. Just how to do this is beyond the scope |
| 21 | of this document. However, if the card is the only Ethernet card in |
| 22 | the system, executing: |
| 23 | |
| 24 | ifconfig eth0 |
| 25 | |
| 26 | should display something like this: |
| 27 | |
| 28 | eth0 Link encap:Ethernet HWaddr 00:60:67:62:31:D4 |
| 29 | |
| 30 | plust some more lines. Your HWaddr will be different. As long as you see |
| 31 | the HWaddr line, your card should be working. |
| 32 | |
| 33 | DO NOT assign an IP address to the Ethernet card. DO NOT configure the |
| 34 | card to come up at boot time. |
| 35 | |
| 36 | 2. Configure various files |
| 37 | -------------------------- |
| 38 | |
| 39 | Several files need editing. The easiest way to do this is to run |
| 40 | the following command as root: |
| 41 | |
| 42 | pppoe-setup |
| 43 | |
| 44 | Answer the questions and you should be all set. If you want to know what |
| 45 | goes on behind the scenes, continue reading this document. If you don't |
| 46 | care and your connection works, stop reading. :-) |
| 47 | |
| 48 | 3. Edit pap-secrets |
| 49 | ------------------- |
| 50 | |
| 51 | Edit the "pap-secrets" file, inserting your proper user-ID and password. |
| 52 | Install the file (or copy the relevant lines) to /etc/ppp/pap-secrets. |
| 53 | Your ISP may use CHAP authentication. In this case, add the line to |
| 54 | /etc/ppp/chap-secrets. |
| 55 | |
| 56 | 4. Edit /etc/ppp/pppoe.conf |
| 57 | ----------------------------- |
| 58 | |
| 59 | The file /etc/ppp/pppoe.conf contains configuration information for the |
| 60 | DSL connection. You need to edit the following items: |
| 61 | |
| 62 | - Change ETH=eth1 to the correct Ethernet device for your modem. |
| 63 | - Change USER=bxxxnxnx@sympatico.ca to your proper DSL user-ID. |
| 64 | |
| 65 | Don't edit any of the other settings unless you're an expert. |
| 66 | |
| 67 | 5. Set up DNS |
| 68 | ------------- |
| 69 | |
| 70 | If you are using DNS servers supplied by your ISP, edit the file |
| 71 | /etc/resolv.conf to contain these lines: |
| 72 | |
| 73 | nameserver ip_addr_of_first_dns_server |
| 74 | nameserver ip_addr_of_second_dns_server |
| 75 | |
| 76 | For example: |
| 77 | |
| 78 | nameserver 204.101.251.1 |
| 79 | nameserver 204.101.251.2 |
| 80 | |
| 81 | |
| 82 | 6. Firewall your machine |
| 83 | ------------------------ |
| 84 | |
| 85 | MAKE SURE YOU FIREWALL YOUR MACHINE. A sample firewall script is given |
| 86 | in the shell script "firewall" To install the script: |
| 87 | |
| 88 | a) Copy it to /etc/rc.d/init.d/firewall |
| 89 | b) Type: chkconfig firewall on |
| 90 | c) Start the firewall: sh /etc/rc.d/init.d/firewall start |
| 91 | |
| 92 | (The above procedure works ONLY on Red Hat-like systems.) |
| 93 | |
| 94 | You may want to tweak the script somewhat. |
| 95 | |
| 96 | 7. Bring up the connection at boot time |
| 97 | --------------------------------------- |
| 98 | |
| 99 | On a Red Hat system, the installation procedure should have installed |
| 100 | a script called /etc/rc.d/init.d/pppoe. To bring up the connection |
| 101 | at boot time, just type this command as root: |
| 102 | |
| 103 | chkconfig --add pppoe |
| 104 | |
| 105 | On non-Red-Hat systems, add this line to the end |
| 106 | of /etc/rc.d/rc.local: |
| 107 | |
| 108 | /usr/sbin/pppoe-start |
| 109 | |
| 110 | 8. Configure LAN Hosts |
| 111 | ---------------------- |
| 112 | |
| 113 | If you have a LAN behind the firewall, you have to lower the TCP |
| 114 | maximum segment size from the normal 1460 to 1452 (or better, 1412.) |
| 115 | You have two options: Either set the MTU of all the interfaces on |
| 116 | other hosts on the LAN to 1452, or use the "-m 1412" option to pppoe. |
| 117 | The "-m" option for pppoe is far simpler and makes it easier to add |
| 118 | hosts to the LAN, but consumes some extra CPU time. |
| 119 | |
| 120 | If you want to manually configure the LAN hosts, here's how: |
| 121 | |
| 122 | In Linux, use: "ifconfig eth0 mtu 1452". For best results, put this |
| 123 | in an /etc/rc.d/rc.local script. |
| 124 | |
| 125 | For Windows, machines, see http://lan.cns.ksu.edu/OS/WIN95/slip95.htm. |
| 126 | Set the MaxMTU to 1452. |
| 127 | |
| 128 | 9. Commands to control the PPPoE link |
| 129 | ------------------------------------- |
| 130 | |
| 131 | As root, bring up the link by typing: pppoe-start |
| 132 | As root, bring down the link by typing: pppoe-stop |
| 133 | |
| 134 | That's it! |
| 135 | |
| 136 | -- |
| 137 | David F. Skoll <dfs@roaringpenguin.com> | Roaring Penguin Software Inc. |
| 138 | http://www.roaringpenguin.com | |
| 139 | |
| 140 | PROBLEMS! DAVE, IT DOESN'T WORK! |
| 141 | --------------------------------- |
| 142 | |
| 143 | Here are some problems PPPoE users have encountered. |
| 144 | |
| 145 | ----------------------------------------------------------------------------- |
| 146 | A) Can't see the Ethernet interface |
| 147 | |
| 148 | Well, I can't really help you here. To use these instructions, you must |
| 149 | have Linux working to the point where it recognizes your Ethernet card. |
| 150 | If you type "ifconfig ethx" and you get back a HWAddr value, your Ethernet |
| 151 | card is probably OK. But I really can't help with hardware configuration |
| 152 | issues. |
| 153 | |
| 154 | ----------------------------------------------------------------------------- |
| 155 | B) Connection seems to come up, but I can't browse the web or ping anything |
| 156 | |
| 157 | You probably don't have DNS set up. See step 6. |
| 158 | |
| 159 | ----------------------------------------------------------------------------- |
| 160 | C) Can't compile PPPoE |
| 161 | |
| 162 | Make sure you have "make", the C compiler and all development header |
| 163 | files installed. I only test rp-pppoe on Linux. It might not work on |
| 164 | *BSD and probably won't work on any other version of UNIX. |
| 165 | |
| 166 | ----------------------------------------------------------------------------- |
| 167 | D) pppd complains about (i) "unknown option pty" or (ii) "pty option precludes |
| 168 | specifying device name" |
| 169 | |
| 170 | (i) Your pppd is too old. You need at least 2.3.7. |
| 171 | (ii) Your /etc/ppp/options file is not empty. Empty it! |
| 172 | |
| 173 | ----------------------------------------------------------------------------- |
| 174 | E) pppoe dies with the log message "Message too long" |
| 175 | |
| 176 | You set the MTU of the Ethernet interface connected to the DSL modem |
| 177 | to less than 1500. Don't do that. |
| 178 | |
| 179 | ----------------------------------------------------------------------------- |
| 180 | F) Internal hosts can't see the Internet |
| 181 | |
| 182 | Do you have masquerading set up? I can't help you in great detail, but |
| 183 | see the IPCHAINS-HOWTO and the IP-Masquerade mini-HOWTO. |
| 184 | |
| 185 | ----------------------------------------------------------------------------- |
| 186 | G) Authentication fails |
| 187 | |
| 188 | Make sure you have the right secret in /etc/ppp/pap-secrets. Your ISP |
| 189 | may be using CHAP; it won't hurt to copy the line to /etc/ppp/chap-secrets. |
| 190 | |
| 191 | Also, MAKE SURE that /etc/ppp/options is EMPTY. The "pppoe-connect" script |
| 192 | supplies all required options on the command line; additional options |
| 193 | in /etc/ppp/options may mess things up. |
| 194 | |
| 195 | ----------------------------------------------------------------------------- |
| 196 | H) VPN software does not work |
| 197 | |
| 198 | If you are using VPN software on a Windows or Linux machine with another |
| 199 | Linux machine running PPPoE as the gateway, you MUST NOT use the "-m" option |
| 200 | to pppoe. This alters IP packets, which will break any VPN which uses IPSec. |
| 201 | In /etc/ppp/pppoe.conf, set CLAMPMSS to "no". You'll also have to reduce |
| 202 | the MTU on the hosts behind the gateway to 1452. |
| 203 | |
| 204 | ----------------------------------------------------------------------------- |
| 205 | I) I can browse some web sites just fine, but others stall forever. |
| 206 | |
| 207 | There is probably a buggy router or firewall between you and the Web server. |
| 208 | One possible workaround: In /etc/ppp/pppoe.conf, find the line which reads: |
| 209 | |
| 210 | CLAMPMSS=1412 |
| 211 | |
| 212 | Try lowering the 1412 until it works (go down in steps of 100 or so.) Each |
| 213 | time you lower the value, you have to restart your connection like this: |
| 214 | |
| 215 | pppoe-stop; pppoe-start |
| 216 | |
| 217 | This should work around buggy routers which do not support Path MTU discovery. |
| 218 | |
| 219 | ----------------------------------------------------------------------------- |
| 220 | J) Whenever I connect using DSL, my internal LAN no longer sees the gateway |
| 221 | |
| 222 | You are more than likely running a 2.0.X Linux kernel. To solve this |
| 223 | problem, give the Ethernet card connected to the DSL modem a fake IP |
| 224 | address. For example, if eth0 is your internal LAN card and eth1 goes to |
| 225 | the DSL modem, do something like this: |
| 226 | |
| 227 | ifconfig eth1 10.0.0.1 netmask 255.255.255.0 |
| 228 | |
| 229 | (You may have to choose a different IP address; experiment.) |
| 230 | ----------------------------------------------------------------------------- |
| 231 | K) How can I run a script every time I connect and get a new IP address? |
| 232 | |
| 233 | Put the script in /etc/ppp/ip-up. See the pppd(8) man page. |
| 234 | ----------------------------------------------------------------------------- |
| 235 | L) Nothing works! |
| 236 | |
| 237 | You may need to put your Ethernet card in half-duplex, 10Mb/s mode to |
| 238 | work with the DSL modem. You may have to run a DOS program to do this, |
| 239 | or pass special parameters to the Linux driver. |
| 240 | |
| 241 | Some providers object to attempts to set the MRU or MTU. Try removing |
| 242 | "mtu 1492 mru 1492" from PPP_STD_OPTIONS in the pppoe-connect script. |
| 243 | This problem has been seen with an ISP in Hong Kong. |
| 244 | |
| 245 | Your DSL provider may be using non-standard PPPoE frames or require |
| 246 | something special in the Service-Name field. If you have two computers, |
| 247 | you can try sniffing out these values with the "pppoe-sniff" program. |
| 248 | Type "man pppoe-sniff" for details. If you don't have two computers, |
| 249 | you'll have to ask your DSL provider if it uses non-standard PPPoE frames |
| 250 | or special Service-Name fields. Good luck getting an answer... |
| 251 | |
| 252 | If pppoe-sniff indicates that nothing is amiss, make sure the Ethernet |
| 253 | card associated with the DSL modem does NOT have a valid IP address. |
| 254 | (NOTE: For 2.0 kernels, you may have to give it a fake IP address |
| 255 | which is not on your internal subnet. Something like 192.168.42.42 |
| 256 | might work if you are not using 192.168.42.*) |
| 257 | |
| 258 | If you are using synchronous PPP on a slow machine, try switching to |
| 259 | asynchronous PPP. |
| 260 | |
| 261 | Make sure no entries in the routing table go through the Ethernet card |
| 262 | connected to the DSL modem. You might want to add these lines in |
| 263 | pppoe-connect: |
| 264 | |
| 265 | ifconfig ethx down |
| 266 | ifconfig ethx up mtu 1500 |
| 267 | |
| 268 | which should reset things to sane values. |
| 269 |