Custom linux router, the story..
I have two separate internet providers, two separate static ranges, one from each provider, and a LAN. The purpose of the exercise here was to split traffic between the two providers on an equal 50/50...
View ArticleCustom linux router, routing, split access and more..
So, now I have got this router set up and working, it was time to customize it somewhat. In terms of networking, we have 3 10/100 ethernet ports and one wireless adapter, and this is set up as follows:...
View ArticleSplit access SSH problems
So far everything works flawlessly, all applications, protocols and service with the split access setup, but I have a strange bug with SSH, and it only affects SSH clients built on openssl, such as...
View ArticleLAMP Optimization
Here’s 3 easy steps to immediately boost your Linux Apache MySQL PHP installation. – Apache: Make sure you’re using the correct number of spare threads and minimum and maximum constraints. Too few...
View ArticleBandwidth Limiting HOWTO with linux, tc and iproute2
I’ve recently optimized the scripts used for bandwidth management in one of our UK facilities and I thought I’d post a quick howto on it. My setup here is a live feed entering eth0 on this linux router...
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VMware Time Problems
Using VMware Server on an SMP machine has long caused me problems. Although the host machine’s clock generally remains correct, the guest machines are often 2-5 times too slow. Running a local time...
View ArticleExtending tc and iproute2. Linux routing split access multiple uplinks...
It’s been a while since the last post, so I thought I’d post a followup article to http://www.adampalmer.me/iodigitalsec/bandwith-limiting-with-linux-tc-and-iproute2/ which focused on bandwidth...
View ArticleLinux virtualization, vmware, xen, hosting, and squeezing the most out of...
I’d guess that 90% of hosting providers ‘oversell’. This essentially means that should they have 1,000GB allocated, they might offer 15 packages of 100Gb to 15 of their customers, banking on the fact...
View ArticleQuick Linux and Windows OpenVPN HOWTO and tutorial, including VPN routing
OpenVPN is a popular Windows/Linux VPN Server/Client pair. I think there’s a separate GUI available for it if you’re so minded. This howto will cover command line usage only. I’ll provide example...
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NetCat tutorial for Linux & Windows, HOWTO, nc
I wrote this article some time ago, but thought I’d publish it here for reference. This text is dual licenced under the GFDL and GPL There are two known versions of netcat. The version of netcat used...
View Article95th percentile billing explaination
95th percentile billing commonly misspelled as “percential” is a method used by some NOCs to change for bandwidth. The system is simple and essentially discards the top 5% of your traffic peaks, and...
View ArticleWireless Hacking, Problems with WEP, Wireless Security and WPA
Unfortunately today there are still a huge range of wireless OEM equipment being shipped with WEP as standard. WEP has been known as vulnerable for a long time. This HOWTO assumes Linux familiarity,...
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APNIC Box – Linux on a Mikrotik 532a, Part 1 – The Device
I put this device together for fun sometime around the start of 2007. The ideas that spawned this was using OpenWRT on a Linksys WRT54G access point. A surprisingly powerful and full linux distro with...
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APNIC Box – Linux on a Mikrotik 532a, Part 2 – Hardware Modifications
Follow on from 01 Oct 08 APNIC Box – Linux on a Mikrotik 532a, Part 1 Custom Hardware Modifications Here’s a labelled image of the inside of the device. You can also look towards the bottom left of the...
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APNIC Box – Linux on a Mikrotik 532a, Part 3 – Installing Debian, Prebuilt...
Follow on from 01 Oct 08 APNIC Box – Linux on a Mikrotik 532a, Part 2 The device runs a 2.4.30 kernel on a debian woody (mipsel) environment. If anyone can contribute anything for 2.6.x and debian...
View ArticleLinux on a Mikrotik 532a, Part 4 – Customization, Debian Scripts, Shaping,...
Follow On From: 05 Oct 08 APNIC Box – Linux on a Mikrotik 532a, Part 3 – Installing Debian, Prebuilt Disk Image Following on from the previous article, I’ve written some scripts which you’ll find in...
View ArticleLinux on a Mikrotik 532a , Part 5 Final – OpenWRT and Custom Scripts
Follow on from: http://www.adampalmer.me/iodigitalsec/linux-on-a-mikrotik-532a-part-4-customization-debian-scripts-shaping-firewall-nat-picolcd/ I’ve used OpenWrt previously to this project to build...
View Articlersync over SSH, SSH key login, public keys, automated backups
This tutorial will cover how to set up a simple backup job between two machines using rsync and ssh. You will need HOST A and HOST B, whereby HOST B is your target backup service. On HOST B: ssh-keygen...
View ArticleA BIND9 zonefile and commentary
I’m often asked for a copy of various zone files for Bind, that other users may use as a template. Here’s the zonefile for www.adampalmer.me/iodigitalsec: $TTL 604 @ IN SOA iodigitalsec.com....
View ArticleSimple POP3 Communication HOWTO
POP3 is an incredibly simple protocol, and with the most basic commands, you can access your POP3 server ‘by hand’ with this POP3 HOWTO without the need for a client. You can find the entire POP3 RFC...
View ArticleLinux IP Address Configuration Static or DHCP
It’s simple really.. You can define a static IP as follows: ifconfig <interface> <ipaddress> netmask <mask> broadcast <broadcast> e.g. ifconfig...
View ArticleDNS based Load Balancing
There are two main options for DNS based load balancing. The first and most simple is the round robin option. We can use this for ‘A (alias) records’ and ‘MX (Mail-eXchanger) records’. We can specify a...
View ArticleLinux and the Huawei HSDPA 3G E220 modem for mobile broadband
Installing the Huawei E220 modem under Linux is so so easy. Probably easier than running through the Windows XP Setup tool actually! Prerequisites: 1. Kernel version equal to or greater than 2.6.20...
View ArticleEthernet over mains power lines
I’ve been using a really clever device for the last few years that a lot of people seem to be unaware exists. It’s an ethernet over powerlines adapter – one such example is the Devolo dLAN. In a...
View ArticleMySQL Master-Master Replication, Heartbeat, DRBD, Apache, PHP, Varnish MegaHOWTO
I created this HOWTO while building a new development environment today. The intention is to take a single Apache2/Varnish/MySQL environment and scale it to two servers, with one effectively a...
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