{"id":1086,"date":"2021-09-23T13:58:45","date_gmt":"2021-09-23T13:58:45","guid":{"rendered":"https:\/\/www.practicallynetworked.com\/?page_id=1086"},"modified":"2021-10-05T16:59:18","modified_gmt":"2021-10-05T16:59:18","slug":"linksys-cable-router-help","status":"publish","type":"post","link":"https:\/\/www.practicallynetworked.com\/linksys-cable-router-help\/","title":{"rendered":"Linksys Cable\/DSL Router Help &#8211; Security,VPN,PPPoE"},"content":{"rendered":"<p><b><span style=\"font-family: Arial; font-size: medium;\">You have a Linksys Etherfast Cable \/ DSL router and are having problems with:<\/span><\/b><\/p>\n<ul>\n<li><b><span style=\"font-family: Arial; font-size: medium;\"><a href=\"https:\/\/www.practicallynetworked.com\/linksys_router_help.htm\">Setup \/ Basic Functionality<\/a><\/span><\/b><\/li>\n<li><b><span style=\"font-family: Arial; font-size: medium;\"><a href=\"https:\/\/www.practicallynetworked.com\/linksys_router_help_pg2.htm\">Firmware upgrades (including MacOs issues)<\/a><\/span><\/b><\/li>\n<li><b><span style=\"font-family: Arial; font-size: medium;\">Security, VPN\/PPTP, PPPoE\u00a0<\/span><\/b><b><span style=\"font-family: Arial; font-size: medium;\">[This Page]<\/span><\/b><\/li>\n<li><b><span style=\"font-family: Arial; font-size: medium;\"><a href=\"https:\/\/www.practicallynetworked.com\/linksys_router_help_pg4.htm\">Port Forwarding \/ Special Applications \/ Dynamic DNS \/ Logging<\/a><\/span><\/b><\/li>\n<\/ul>\n<hr size=\"1\" \/>\n<table>\n<tbody>\n<tr>\n<td valign=\"top\" width=\"236\">\n<ul>\n<li>\n<p align=\"left\"><span style=\"color: #ff0000; font-family: Arial Narrow;\"><b>8\/9\/01<\/b><\/span><br \/>\n<b><a href=\"https:\/\/www.practicallynetworked.com\/#password\">Password visible in admin page source code security vulnerability<\/a><\/b><\/p>\n<\/li>\n<li>\n<p align=\"left\"><span style=\"color: #ff0000; font-family: Arial Narrow;\"><b>Update 9\/3\/01<\/b><\/span><b><a href=\"https:\/\/www.practicallynetworked.com\/#Problems\"><br \/>\nProblems using PPPoE AND VPN<\/a><\/b><\/p>\n<\/li>\n<li>\n<p align=\"left\"><span style=\"color: #ff0000; font-family: Arial Narrow;\"><b>Update 2\/24\/01<\/b><\/span><b><a href=\"https:\/\/www.practicallynetworked.com\/#PPTP\"><br \/>\nUsing PPTP (MS VPN)<\/a><\/b><\/p>\n<\/li>\n<li>\n<p align=\"left\"><span style=\"color: #ff0000; font-family: Arial Narrow;\"><b>Update 6\/5\/00<\/b><\/span><b><a href=\"https:\/\/www.practicallynetworked.com\/#ssh\"><br \/>\nUsing ssh<\/a><\/b><\/p>\n<\/li>\n<li>\n<p align=\"left\"><span style=\"color: #ff0000; font-family: Arial Narrow;\"><b>Update 9\/8\/01<\/b><\/span><b><br \/>\n<\/b><b><a href=\"https:\/\/www.practicallynetworked.com\/#IPsec\">Using IPsec<\/a><\/b><\/p>\n<\/li>\n<\/ul>\n<\/td>\n<td valign=\"top\" width=\"235\">\n<ul>\n<li>\n<p align=\"left\"><span style=\"color: #ff0000; font-family: Arial Narrow;\"><b>7\/11\/00<\/b><\/span><br \/>\n<b><span style=\"color: #ff0000;\"><a href=\"https:\/\/www.practicallynetworked.com\/tftp_problem.htm\">Security problem with tftp.exe firmware update program.<\/a><\/span><\/b><\/p>\n<\/li>\n<li>\n<p align=\"left\"><a href=\"https:\/\/www.practicallynetworked.com\/#Open\"><b>Open ports on WAN side (security issues)<\/b><\/a><\/p>\n<\/li>\n<li>\n<p align=\"left\"><span style=\"color: #ff0000; font-family: Arial Narrow;\"><b>Updated 4\/6\/00<\/b><\/span><b><br \/>\n<a href=\"https:\/\/www.practicallynetworked.com\/#stealth\">Getting a &#8220;stealth&#8221; ShieldsUP report.<\/a><\/b><\/p>\n<\/li>\n<li>\n<p align=\"left\"><span style=\"color: #ff0000; font-family: Arial Narrow;\"><b>Updated 9\/23\/00<\/b><\/span><b><br \/>\n<a href=\"https:\/\/www.practicallynetworked.com\/#PPPoE\">Using PPPoE<\/a><\/b><\/p>\n<\/li>\n<\/ul>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<hr size=\"1\" \/>\n<p>You can also try the\u00a0<b><a href=\"http:\/\/www.linksys.com\/support\/support.asp?spid=1\" target=\"_offsite\" rel=\"noopener\">Linksys Support page<\/a><\/b>\u00a0and\u00a0<b><a href=\"http:\/\/www.linksys.com\/tech_helper\/default.html\" target=\"_offsite\" rel=\"noopener\">Tech Helper<\/a><\/b>\u00a0for the router, or\u00a0<a name=\"contact\"><\/a>contact Linksys support via one of the following methods:<\/p>\n<div align=\"center\">\n<p>&nbsp;<\/p>\n<table border=\"0\" width=\"300\" cellspacing=\"1\" bgcolor=\"#FFFF00\">\n<tbody>\n<tr>\n<td valign=\"top\"><span style=\"font-family: Arial; font-size: small;\"><b>Customer Support Phone:<\/b><\/span><\/td>\n<td valign=\"top\"><span style=\"font-family: Arial; font-size: small;\">800-326-7114<br \/>\n949-261-1288<\/span><\/td>\n<\/tr>\n<tr>\n<td valign=\"top\"><span style=\"font-family: Arial; font-size: small;\"><b>Fax:<\/b><\/span><\/td>\n<td valign=\"top\"><span style=\"font-family: Arial; font-size: small;\">949-261-8868<\/span><\/td>\n<\/tr>\n<tr>\n<td valign=\"top\"><span style=\"font-family: Arial; font-size: small;\"><b>Email:<\/b><\/span><\/td>\n<td valign=\"top\"><span style=\"font-family: Arial; font-size: small;\">support@linksys.com<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>&nbsp;<\/p>\n<\/div>\n<hr size=\"1\" \/>\n<p><b><span style=\"font-family: Arial; font-size: large;\">Open ports on WAN side (security issues)<\/span><\/b><\/p>\n<p><span style=\"color: #ff0000;\"><b>Security warning!\u00a0<\/b><\/span>Please follow the User Guide&#8217;s instructions and change the admin pages&#8217; password\u00a0<b><i>during your intitial setup<\/i><\/b>.\u00a0<b><i>The admin HTTP server is accessible via the WAN side of the router by default.<\/i><\/b>\u00a0 If you don&#8217;t change the admin password to a\u00a0<b><a href=\"http:\/\/www.hill.com\/library\/archives\/password.shtml\" target=\"_blank\" rel=\"noopener\">strong password<\/a><\/b>, you may find uninvited &#8220;guests&#8221; in your LAN&#8217;s computers.<\/p>\n<p><b>To fix the above security problem, download and install the\u00a0<a href=\"https:\/\/www.practicallynetworked.com\/linksys_router_help_pg2.htm#Firmware\">firmware update<\/a>, if your router has firmware earlier than V1.22.\u00a0\u00a0<\/b>Upgrade instructions are in a ReadME doc that comes with the update.<\/p>\n<hr \/>\n<p><b><span style=\"color: #ff0000; font-family: Arial Narrow; font-size: large;\">Updated 9\/3\/01\u00a0<\/span><span style=\"font-family: Arial;\"><big>Problems using PPPoE AND VPN<\/big><\/span><\/b><\/p>\n<p>If you are trying to use either PPTP or IPsec tunnels over a PPPoE connection, you may have problems establishing a connection. \u00a0In some firmware versions there is a problem with the router&#8217;s ability to properly adjust the packet size for a connection that uses\u00a0<b>BOTH PPPoE and one of the VPN protocols<\/b>.<\/p>\n<p><b>Upgrading to version 1.39 or higher<\/b>\u00a0firmware will fix the packet size problem.\u00a0 You then may need to forward ports to your VPN client, based on the type of VPN connection you are using.<\/p>\n<hr \/>\n<p><b><span style=\"color: #ff0000; font-family: Arial Narrow;\"><br \/>\nUpdated 9\/23\/00\u00a0<\/span><big>Using\u00a0<a name=\"PPPoE\"><\/a>PPPoE<br \/>\n<\/big><\/b><\/p>\n<hr size=\"1\" \/>\n<p><span style=\"color: #ff0000;\"><b>If you are having problems maintaining a PPPoE connection, try V1.35 or higher firmware.\u00a0 See more firmware info on\u00a0<a href=\"https:\/\/www.practicallynetworked.com\/linksys_router_help_pg2.htm\">this page<\/a>.<\/b><\/span><\/p>\n<p>There&#8217;s also a Windows application you can try.\u00a0<b><a href=\"https:\/\/www.practicallynetworked.com\/pppoe_alive.htm\">Go here<\/a><\/b>\u00a0for more info.<\/p>\n<p>Also see the PPPoE help information on\u00a0<b><a href=\"https:\/\/www.practicallynetworked.com\/pppoe_nat.htm\">this page.<\/a><\/b><\/p>\n<hr size=\"1\" \/>\n<p>NOTE: If you are using a PPPoE client like WinPOET or other similar programs supplied by your ISP, do the following:<\/p>\n<ol>\n<li>\n<p align=\"left\">Upgrade to the V1.22 or higher firmware.<\/p>\n<\/li>\n<li>\n<p align=\"left\">Enable PPPoE on the router Setup page and enter your Username and Login information into the boxes provided on the router Setup page.<\/p>\n<\/li>\n<li>\n<p align=\"left\">Disable or remove any PPPoE client applications (WinPOET, Enternet, Access Manager) from your Client computers.<\/p>\n<\/li>\n<\/ol>\n<p>You now should be able to connect to the Internet and the router will take care of managing the PPPoE login.<\/p>\n<hr \/>\n<p><b><span style=\"color: #ff0000; font-family: Arial; font-size: large;\">Updated 2\/24\/01<\/span><span style=\"color: #ff0000; font-family: Arial Narrow;\"><br \/>\n<\/span><span style=\"font-family: Arial;\"><big>Using PPTP (MS VPN)<\/big><\/span><\/b><\/p>\n<p><b><i>NOTE: If you are using V1.30.5 or higher firmware, make sure you enable PPTP pass-through on the Filters Admin page.<\/i><\/b><\/p>\n<p><b>PPTP<\/b>\u00a0is Microsoft&#8217;s protocol for Virtual Private Networks (VPN). If you have PPTP Clients on your LAN, you just need to enable PPTP pass-thru as noted above.\u00a0 You also need to properly configure a VPN connection profile in each of your PPTP clients.<\/p>\n<p><b>NOTE:\u00a0<\/b>Although multiple PPTP clients can be passed thru,<b>\u00a0<span style=\"color: #ff0000;\">only one PPTP client can connect per PPTP server.\u00a0 (<\/span><\/b>This is a common limitation for inexpensive NAT routers.)<\/p>\n<p>Many users have reported problems accessing a PPTP\u00a0<b><i>server<\/i><\/b>\u00a0on the LAN side of the router from the Internet.\u00a0 This problem was fixed as of the V1.23 firmware update, so just upgrade to the latest firmware if your firmware revision is lower than 1.23.<\/p>\n<p><b><i>NOTE: No matter which version firmware you use, you will need to set the PPTP server computer as the DMZ computer and remove any Port 1723 forwarding.<\/i><\/b><\/p>\n<p>You can find more general PPTP information on\u00a0<b><a href=\"https:\/\/www.practicallynetworked.com\/pptp_help.htm\">this page<\/a><\/b>, and general VPN help on\u00a0<b><a href=\"https:\/\/www.practicallynetworked.com\/VPN_help.htm\">this page<\/a><\/b>.<\/p>\n<hr \/>\n<p><span style=\"font-family: Arial; font-size: small;\"><br \/>\n<\/span><b><span style=\"color: #ff0000; font-family: Arial; font-size: large;\">9\/8\/01\u00a0<\/span><\/b><b><span style=\"font-family: Arial; font-size: large;\">Using\u00a0<a name=\"IPsec\"><\/a>IPsec<\/span><\/b><\/p>\n<p><b><i>NOTE: If you are using V1.30.5 or higher firmware, make sure you enable IPsec pass-through on the Filters Admin page.<\/i><\/b><\/p>\n<p>IPSec support was added in 1.30.\u00a0 We&#8217;ve received successful reports of the following IPSec clients working with the new firmware:<\/p>\n<ul>\n<li>\n<p align=\"left\"><b>Checkpoint<\/b>\u00a0VPN-1 (see\u00a0<b><a href=\"http:\/\/www.phoneboy.com\/fw1\/faq\/0141.html\" target=\"_blank\" rel=\"noopener\">this link<\/a><\/b>\u00a0if you have problems)<\/p>\n<\/li>\n<li>\n<p align=\"left\"><b>Bay Networks<\/b>\u00a0Extranet<\/p>\n<\/li>\n<li>\n<p align=\"left\"><b>Redcreek<\/b>\u00a0Ravilin\u00a0(with 1.23.4 firmware)<\/p>\n<\/li>\n<li>\n<p align=\"left\"><b>Cisco\u00a0<\/b>Altiga<br \/>\n[no port forwarding. Set\u00a0<b>&#8220;allow NAT passthru&#8221;<\/b>\u00a0in Altiga client]<\/p>\n<\/li>\n<li>\n<p align=\"left\"><b>Cisco 3000\u00a0<\/b>(use 1.39 firmware)<\/p>\n<\/li>\n<li>\n<p align=\"left\"><b>Netscreen-5e<\/b>\u00a0 VPN\/Firewall appliance (Thnx Mike Johnson!)<br \/>\n[Netscreen-Remote 5.02 client was able to use both manual keys (IPSEC) and preshared keying (IPSEC and IKE) to successfully negotiate a connection to a Netscreen-5e VPN appliance]<\/p>\n<\/li>\n<li>\n<p align=\"left\"><b>Symantec<\/b>\u00a0<b>RaptorMobile\u00a0<\/b>VPN client 6.5.2<\/p>\n<\/li>\n<\/ul>\n<hr size=\"1\" \/>\n<p align=\"left\"><b>NOTE:\u00a0<\/b>We&#8217;ve also received a\u00a0<b>negative<\/b>\u00a0report for\u00a0<b>Redcreek RavlinSoft 3.40 NT<\/b>\u00a0and firmware versions 1.30 and 1.33 BETA. The symptom is that RavlinSoft fails to establish a SA; it looks like it does not receive the Radius response after the UserID and Password are entered.<\/p>\n<hr size=\"1\" \/>\n<p><b><a href=\"http:\/\/www.compatible.com\/index1.html\" target=\"_blank\" rel=\"noopener\">Compatible Systems<\/a>\u00a0<\/b>(now a part of Cisco)\u00a0<b>IntraPort VPN client<\/b>, which is IPSec based, will work, even without IPsec forwarding turned on.<\/p>\n<p><b>NOTE:<\/b>\u00a0The IntraPort client must be used with an IntraPort server. You can download at the IntraPort Client Reference Guide\u00a0<b><a href=\"ftp:\/\/ftp.compatible.com\/files\/Documentation\/IntraPort_Client\/VPN_Client_v3.8.pdf\" target=\"_blank\" rel=\"noopener\">here<\/a><\/b>\u00a0(in PDF format), or find out more about the IntraPort product line\u00a0<b><a href=\"http:\/\/www.compatible.com\/intraport_shortcut\/index.html\" target=\"_blank\" rel=\"noopener\">here<\/a><\/b>.<\/p>\n<p><span style=\"color: #ff0000; font-family: Arial Narrow;\"><b>5\/22\/00\u00a0<\/b><\/span>Try this if you&#8217;re having problems getting the\u00a0<b>IntraPort VPN<\/b>\u00a0working:<\/p>\n<p><span style=\"font-family: Arial; font-size: small;\">At first I couldn&#8217;t get VPN to work. I tried all sorts of things and no luck. I was able to watch packets go out through the router to the VPN server at our site, but no packets made it back through the router.<\/span><\/p>\n<p><span style=\"font-family: Arial; font-size: small;\">I actually started up a tech support call with Linksys when I decided to check the VPN client code to see if there was some sort of configuration switch that was obvious. Lucky me, there was exactly such a switch. It was labled &#8220;Use NAT Transparency Mode&#8221;. Since the router does NAT, it seemed like the thing to try. Turned it on, VPN circuit came up and runs fine.<\/span><\/p>\n<p><span style=\"color: #ff0000; font-family: Arial Narrow;\"><b>8\/2\/00\u00a0<\/b><\/span>Still having problems getting IPsec to work?\u00a0<b><a href=\"https:\/\/www.practicallynetworked.com\/VPN_help.htm#Header_Auth\">Check this<\/a><\/b>. General VPN help can be found on\u00a0<b><a href=\"https:\/\/www.practicallynetworked.com\/VPN_help.htm\">this page<\/a><\/b>, including a link to a\u00a0<b><a href=\"http:\/\/www.phoneboy.com\/fw1\/\" target=\"_blank\" rel=\"noopener\">very complete Checkpoint Firewall-1 FAQ page<\/a><\/b>.<\/p>\n<hr \/>\n<p><b><span style=\"font-family: Arial;\"><big>Getting a stealth ShieldsUP report.<\/big><\/span><\/b><\/p>\n<p>The Linksys responds to a port probe by replying with an &#8220;open&#8221; or &#8220;closed&#8221; status.\u00a0 This reply (vs. not replying at all) keeps you from getting a &#8220;stealth&#8221; result from the\u00a0<a href=\"http:\/\/grc.com\/x\/ne.dll?bh0bkyd2\" target=\"_blank\" rel=\"noopener\"><b>ShieldsUp<\/b><\/a>\u00a0port probe test.<\/p>\n<p>Although &#8220;stealth&#8221; isn&#8217;t a important as you might think (especially if you then are opening ports or using the\u00a0<b>DMZ<\/b>\u00a0mode for special applications&#8230;\u00a0<b><a href=\"https:\/\/www.practicallynetworked.com\/sharing\/securnet.htm#Stealth\">read this<\/a><\/b>\u00a0for more info), you can get a &#8220;stealth&#8221; report by using the DMZ feature and entering an IP address for a computer that doesn&#8217;t exist.\u00a0 If you are using the built-in DHCP server, then use an address between\u00a0<b>192.168.1.2\u00a0<\/b>and\u00a0<b>192.168.1.99<\/b>\u00a0so that you don&#8217;t accidently collide with a DHCP served address.<\/p>\n<p><span style=\"color: #ff0000; font-family: Arial Narrow;\"><b>Updated 4\/6\/00\u00a0<\/b><\/span>The V1.22 firmware update adds a\u00a0<b>&#8220;Block WAN Request&#8221;<\/b>\u00a0Enable\/Disable option. This is found on the bottom of the\u00a0<b>Filters<\/b>\u00a0page of the Router Admin pages (access it via the &#8220;Advanced&#8221; tab).\u00a0 Here&#8217;s what the Help button description says:<\/p>\n<p><span style=\"font-family: Arial; font-size: small;\">This feature is designed to prevent users from attacking through the Internet. While enabled, the router will drop both the unaccepted TCP request and ICMP packets from the WAN side.\u00a0 The hacker will not find the router by pinging the WAN IP address.<\/span><\/p>\n<hr \/>\n<p><b><span style=\"font-family: Arial;\"><big>Using SSH<\/big><\/span><\/b><\/p>\n<p>Info on ssh clients can be found on\u00a0<b><a href=\"https:\/\/www.practicallynetworked.com\/ssh_clients.htm\">this page<\/a><\/b>.<\/p>\n<p>Here&#8217;s one reader&#8217;s report on using SSH with the router:<\/p>\n<p><span style=\"font-family: Arial; font-size: small;\">Flashed the latest firmware (1.22). It was shipped with 1.21.1. SSH connected through the router first time, no sweat. Using the F-Secure SSH 1 implementation. 3 key DES encryption.<\/span><\/p>\n<hr \/>\n<p><b><span style=\"font-family: Arial;\"><big>Password visible in admin page source code security vulnerability<\/big><\/span><\/b><\/p>\n<p>Earlier versions (1.36 for example) of Linksys router firmware embed the router admin password and PPPoE account information in plain text in the HTML code for the admin and password pages.\u00a0 Access to the router&#8217;s LAN and a network &#8220;sniffer&#8221; are required for the vulnerability to be seen.\u00a0 The vulnerability can be fixed by upgrading to the latest firmware.\u00a0 See this\u00a0<b><a href=\"http:\/\/www.securityfocus.com\/bid\/3141\" target=\"_offsite\" rel=\"noopener\">SecurityFocus article<\/a><\/b>\u00a0for details.<\/p>\n<p><span style=\"color: #ff0000;\"><b><a href=\"https:\/\/www.practicallynetworked.com\/linksys_router_help_pg2.htm#Firmware\">Update 8\/9\/01- 1.39.3 BETA firmware fix available<\/a>.<\/b><\/span><\/p>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>You have a Linksys Etherfast Cable \/ DSL router and are having problems with: Setup \/ Basic Functionality Firmware upgrades (including MacOs issues) Security, VPN\/PPTP, PPPoE\u00a0 Port Forwarding \/ Special Applications \/ Dynamic DNS \/ Logging 8\/9\/01 Password visible in admin page source code security vulnerability Update 9\/3\/01 Problems using PPPoE AND VPN Update 2\/24\/01 Using PPTP (MS VPN) Update 6\/5\/00 Using ssh Update 9\/8\/01 Using IPsec 7\/11\/00 Security problem with tftp.exe firmware update program. Open ports on WAN side (security issues) Updated 4\/6\/00 Getting a &#8220;stealth&#8221; ShieldsUP report. Updated 9\/23\/00 Using PPPoE You can also try the\u00a0Linksys Support <\/p>\n","protected":false},"author":2,"featured_media":5591,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"_links":{"self":[{"href":"https:\/\/www.practicallynetworked.com\/wp-json\/wp\/v2\/posts\/1086"}],"collection":[{"href":"https:\/\/www.practicallynetworked.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.practicallynetworked.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.practicallynetworked.com\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.practicallynetworked.com\/wp-json\/wp\/v2\/comments?post=1086"}],"version-history":[{"count":0,"href":"https:\/\/www.practicallynetworked.com\/wp-json\/wp\/v2\/posts\/1086\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.practicallynetworked.com\/wp-json\/wp\/v2\/media\/5591"}],"wp:attachment":[{"href":"https:\/\/www.practicallynetworked.com\/wp-json\/wp\/v2\/media?parent=1086"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.practicallynetworked.com\/wp-json\/wp\/v2\/categories?post=1086"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.practicallynetworked.com\/wp-json\/wp\/v2\/tags?post=1086"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}