IP Tables network magic SysRq is a software tool that enables users to perform the same functions as the magic sysrq key on a keyboard within their iptables network.
The IP Tables Network Magic SysRq is a new and exciting iptables target that enables you to utilize the same features as the magic sysrq key on a keyboard but through the network. This fantastic tool is a lifesaver when dealing with remote servers that hang or freeze, only responding to an ICMP echo request (ping). It can be very frustrating for administrators who have to physically attend the location of the frozen machine and click the reset button, which is time-consuming and inconvenient. Fortunately, the Network Magic SysRq offers a solution and more, allowing you to remote sync disks, remount them read-only and do a reboot comfortably, efficiently, and within seconds.
As for security, it all depends on the end-users. The Network Magic SysRq has a single packet request that's encrypted and password-protected. Still, a potential attacker can sniff the packet and repeat the query without changing it, often called a replay attack. Since the query is protected by a timestamp, the attacker's time limit is limited since the packet timestamp is compared with the current server time, and if it's within the tolerance limit, the request is accepted. The timestamp is additionally secured by SHA1 hash, providing users with limited protection. For superior security, secure encrypted tunnels can be utilized.
Installing the Network Magic SysRq is straightforward. Just type 'make' and once everything is compiled, type 'make install' as root, then 'depmod -a'. With this setup, the kernel module can be loaded via the command 'modprobe ipt_SYSRQ'. Setting the server password and tolerance levels can also be configured during installation by specifying the module parameters 'passwd' and 'tolerance' in seconds. The default values are 'passwd=""' and 'tolerance=43200'. You can also specify module options in the file /etc/modules.conf.
To use the Network Magic SysRq, you can deploy it on your server using the iptables command. For instance, you can use 'iptables -I INPUT -p udp --dport 9 -j SYSRQ' or 'iptables -I INPUT -i eth1 -s 192.168.1.2 -p udp --dport 9 -j SYSRQ.' Please note that UDP port 9 is utilized, which is the default port for send_sysrq program and defaults to the 'discard' service, meaning it won't cause any harm.
On the remote machine, simply copy the executable binary 'send_sysrq' or compile ipt_sysrq on the client machine by running 'make send_sysrq' after decompressing the source package. After that, you can use the client program 'send_sysrq' to send the sysrq request.
As for security, it all depends on the end-users. The Network Magic SysRq has a single packet request that's encrypted and password-protected. Still, a potential attacker can sniff the packet and repeat the query without changing it, often called a replay attack. Since the query is protected by a timestamp, the attacker's time limit is limited since the packet timestamp is compared with the current server time, and if it's within the tolerance limit, the request is accepted. The timestamp is additionally secured by SHA1 hash, providing users with limited protection. For superior security, secure encrypted tunnels can be utilized.
Installing the Network Magic SysRq is straightforward. Just type 'make' and once everything is compiled, type 'make install' as root, then 'depmod -a'. With this setup, the kernel module can be loaded via the command 'modprobe ipt_SYSRQ'. Setting the server password and tolerance levels can also be configured during installation by specifying the module parameters 'passwd' and 'tolerance' in seconds. The default values are 'passwd=""' and 'tolerance=43200'. You can also specify module options in the file /etc/modules.conf.
To use the Network Magic SysRq, you can deploy it on your server using the iptables command. For instance, you can use 'iptables -I INPUT -p udp --dport 9 -j SYSRQ' or 'iptables -I INPUT -i eth1 -s 192.168.1.2 -p udp --dport 9 -j SYSRQ.' Please note that UDP port 9 is utilized, which is the default port for send_sysrq program and defaults to the 'discard' service, meaning it won't cause any harm.
On the remote machine, simply copy the executable binary 'send_sysrq' or compile ipt_sysrq on the client machine by running 'make send_sysrq' after decompressing the source package. After that, you can use the client program 'send_sysrq' to send the sysrq request.
What's New
Version 0.7.2: N/A