Category Archives: Networking

Setting up Juniper junos command aliases

At command prompt, create the file: root@lab-SRX% vi /var/db/scripts/op/sit.slax version 1.0; ns junos = “*/junos”; ns xnm = “”; ns jcs = “”; import “../import/junos.xsl”; match / { { var $cmd = ‘show interfaces terse’; var $out = jcs:invoke($cmd); copy-of … Continue reading

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GNS3: Offloading DHCP service to another router acting as DHCP server

Most tutorial examples (for reasons of simplicity) will include DHCP server configuration on the same router that’s connected to the multiple VLANs so that IP addresses can be provided to devices on the network. For a more clean (and realistic) … Continue reading

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lightweight HTTP sink using socat

Quick n’ dirty way to run a HTTP sink (on a server that isn’t supposed to have a HTTP server running) to catch bots scanning all machines across your network. socat -T 1 -d -d tcp-l:80,bind=,reuseaddr,fork,su=nobody,crlf system:”echo -e \”\\\”HTTP/1.0 200 … Continue reading

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Watching in real-time IPv4 network interface changes

Note: I ignore local loopback and virtual networks.  Your setup may be different. watch -n 1 ‘ip addr | grep inet | grep -v inet6 | grep -v “” | grep -v  192\.168\.76 | grep -v 172\.16\.  | awk ‘\”{print … Continue reading

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Better Late than Never: following up on Google HTTPS using DHE cipher suites

[Above image is the famous Caesar Cipher] One of the things that irked me about how Google handled the security of their HTTPS traffic was the lack of DHE ciphers.  I banged out a post “Google and Amazon do not … Continue reading

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Today, a new advancement in VRS calling

It’s days like this that make me proud that I’m part of the engineering team at ZVRS. This morning, at the NAD conference, ZVRS worked with Google on a demo of our prototype ZVRS app for Google+ Hangouts. The ZVRS … Continue reading

Posted in Networking, Web/Tech | 6 Comments

Finding IP address of a device on a network.

[zippy] I get asked this question once in a while: “When I plug in a new device to the network, fresh out of the box and it defaults to getting an IP address via DHCP: how the heck do I … Continue reading

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Ubuntu: Installing RRDtool 1.4.5 and php->RRDtool bindings

Installing RRDtool 1.4.5: Ubuntu 11.04 repo only offers older RRDtool 1.4.3, so if need to have a more recent RRDtool on your system: Run the following commands as superuser: sudo su apt-get install libpango1.0-dev libxml2-dev wget tar -zxvf rrdtool-1.4.5.tar.gz … Continue reading

Posted in Linux, Networking | 2 Comments

Bypassing Verizon FIOS Actiontec router and using your own router instead

Verizon loans you the Actiontec router when they come over to install the FIOS service at your home. It is an excellent router in all respects except for one flaw.  The router contains a very small (1K) NAT table which … Continue reading

Posted in Networking | 24 Comments