Category Archives: Networking

Tcpdump usage examples

In most cases you will need root permission to be able to capture packets on an interface. Using tcpdump (with root) to capture the packets and saving them to a file to analyze with Wireshark (using a regular account) is … Continue reading

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USB Rubber Ducky | USB Rubber Ducky

I want one of these 🙂

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Hak5 – Building a high performance home router

This was a pretty cool setup.

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Setting Up a FreeBSD Router, Step-by-Step

HARDWARE INFO: rl0 – NIC facing the 192.168.0.0 network xl0 – NIC facing the 192.168.1.0 network xl1 – NIC facing the modem tun0 – The virtual NIC used by PPP, facing the outside SECTION 1: PRELIMINARY SETUP Install FreeBSD Enable … Continue reading

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Nagios NRPE example setup

Ubuntu #> apt-get install nagios-nrpe-server nagios-nrpe-plugin CentOS and Fedora #> yum install nrpe nagios-plugins-load nagios-plugins-users nagios-plugins-swap nagios-plugins-disk #> chkconfig –add nrpe FreeBSD #> cd /usr/ports/net-mgmt/nrpe* #> make #> make install clean #> In /etc/nagios/nrpe.cfg Set the following dont_blame_nrpe=1 (default set … Continue reading

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Block Port 25 with IPTables

Block all port 25 except from localhost -A INPUT -p tcp -s localhost –dport 25 -j ACCEPT -A INPUT -p tcp –dport 25 -j DROP

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Subnet Mask Cheat Sheet

Addresses Hosts Netmask Amount of a Class C /30 4 2 255.255.255.252 1/64 /29 8 6 255.255.255.248 1/32 /28 16 14 255.255.255.240 1/16 /27 32 30 255.255.255.224 1/8 /26 64 62 255.255.255.192 1/4 /25 128 126 255.255.255.128 1/2 /24 256 … Continue reading

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