This bug, as far as I know, only happends on GV8BAA3.253 versions and is only available on the eth0 local interface. NB: My modem is an Alcatel Speed Touch Home one, therefore Ethernet. Here are the informations about my modem: - active software version : GV8BAA3.253 - firmware : 8706 - Ip local : 10.0.0.1 I did the tests from a basic distribution around LFS kernel 2.4.16 My NMAP version is 2.54BETA30 When I run NMAP -O 10.0.0.1 then the modem reboots As far as I can see this bug only happens on GV8BAA3.253 and only in local network. The LAN is protected from the incomming packets with Firewall rules that couldn't be modified (I don't think it's possible, not with this version anyway). How to know its software version: # ftp modem_ip (default : 10.0.0.138) Connected to 10.0.01 220 Inactivity timer = 120 seconds. Use 'site idle <secs>' to change. Name (10.0.0.138:root): password : ## If you have a message like 421 Service Not Available, remote server has closed connection Login failed. No control connection for command : No such file or directory. ftp > ## It means that you need a password ## To obtain your password, click on the link and read the F.A.Q. (it's in French, ask me for the translations) ## http://www.clubic.com/forum/05/message/2880-0.htm Once you're connected, type: ftp> cd active 250 Changed to /active ftp>ls 200 Connected to 10.0.0.11 port 33376 150 Opening data connection for /bin/ls total 1 -rwxrwxrwx 1 0 0 997001 Jun 29 1971 GV8BAA3.253 <-- it's your active version -rwxrwxrwx 1 0 0 27 Jun 29 1971 start.cmd -rwxrwxrwx 1 0 0 0 Jun 29 1971 active.flg -rwxrwxrwx 1 0 0 32 Jun 29 1971 system.ini -rwxrwxrwx 1 0 0 506 Jun 29 1971 ip.ini -rwxrwxrwx 1 0 0 308 Jun 29 1971 phone.ini -rwxrwxrwx 1 0 0 28 Jun 29 1971 bridge.ini -rwxrwxrwx 1 0 0 0 Jun 29 1971 atmf.ini -rwxrwxrwx 1 0 0 92 Jun 29 1971 pptp.ini -rwxrwxrwx 1 0 0 189 Jun 29 1971 dnsd.ini -rwxrwxrwx 1 0 0 217 Jun 29 1971 dhcp.ini -rwxrwxrwx 1 0 0 203 Jun 29 1971 ppp.ini -rwxrwxrwx 1 0 0 0 Jun 29 1971 cip.ini -rwxrwxrwx 1 0 0 297 Jun 29 1971 nat.ini 226 Options: -l : 0 matches total In order to know the firmware, follow the link above You're not obliged to change the modem in Pro mode, stop at the first telnet command then you'll have your firmware version (8704