The solution of the interruption and shutdown of ADSL modem

A lot of ADSL modem have encountered the problem of stop and crash, which to many ADSL end users online caused a barrier, the following analysis and give a solution.

Fault characteristics

1.10 minutes to half an hour, ADSL modem on the crash, Ping ADSL modem IP, half of the pass, the delay in the thousand millisecond level. Web pages can not open, but QQ, MSN, etc. can also be online, occasionally also send and receive messages.

2. The frequent occurrence of ADSL link disconnection is a phenomenon (within half an hour to appear several times).

3. Frequent occurrence of ATM VC congestion.

4.ADSL Modem working indicator is normal.

Cause of failure

1. Malicious people use the ADSL modem bugs or loopholes to interfere with the routing mode of the Internet users.

2. Virus attacks ADSL modem is also relatively large, and caused the crash. In addition, some fool-like configuration software, as if using the Telnet port of the ADSL modem configuration, after modifying the Telnet ports, these software will not even (the software is the default is to login ADSL modem 23 port, no choice).

Solutions

1. Switch ADSL equipment to bridge working mode instead of routing.

2. Before the ADSL equipment placed an additional hardware firewall equipment, the firewall can not only intercept the intrusion attempt and the system loopholes, but also to prevent Trojan attacks (no conditions can be ignored by the user).

3. Change ADSL Modem's HTTP, Telnet port, lest be attacked by virus easily, method is as follows:

Replace the HTTP, Telnet service port in "Admin→port Setting" with any one of the 61000~62000, but be sure to remember this port, the next time you http/telnet to the ADSL modem, you need to change the login port accordingly.

Note: The modifications need to be saved and restarted: admin → Save and reboot (Commit & Reboot) → save configuration. In this way, each login configuration page is not 80 port, but should be http://192.168.1.1:61080 (61080 is the new port number you modified); Telnet login is no longer 23 port, but Telnet 192.168.1.1 61023;4. Through the RDR mapping, the external to the ADSL modem open port of the attack to the internal, in the ADSL modem to do 4 RDR mapping, the external network to the ADSL modem 21, 23, 69, 80 port access map to the intranet of an unused IP.

Note: 21, 23, 69, 80 ports correspond to FTP, Telnet, TFTP, HTTP services respectively.

5. Open the firewall function of ADSL modem. Click service → firewall (Firewall) to change the attack protection (Attack protection) and DOS protection from the prohibition to license, other settings can refer to "Easy with me to learn the simple configuration of ADSL Modem Firewall" a article.