Blog IndexPosts by TagHome

Dirty Load Balancing

Posted <2016-12-22 Thu 16:14> by Aaron S. Jackson.

I am currently staying at my parents' house over Christmas. They are in the middle of nowhere and have very poor internet connection. They recently had a new ADSL line installed, provided by Andrews & Arnold. While the previous line still has ADSL, they kept it just for telephone service.

This afternoon I spent a bit of time trying to load balance the two connections with a half dead DrayTek router. Unfortunately the ADSL/VDSL port has been burnt out by a strike of lightning. It only supports 3G/4G modems via USB, and there is only one WAN ethernet port.

Due to these restrictions, my only option is to load balance using static routes, to routers on the same subnet. So, there are now three routers.   tplink        aaisp dsl   speedtouch    xilo dsl   draytek       defalt route

The DrayTek is the default route for the subnet and also dishes out the IP addresses. It has the following routing table:

Key: C - connected, S - static, R - RIP, * - default, ~ - private
S~         via    LAN
S~        via    LAN
C~    directly connected    LAN

Basically the internet has been divided in half, split between two connections. The main problem with this is that if one of the connections goes down, half the internet will not be accessible. From what I can tell, the DrayTek does not allow you to define static route priorities or fallover routes. Quick example…

$ traceroute
traceroute to (, 30 hops max, 60 byte packets
 1  my.router (  3.275 ms  3.726 ms  3.704 ms
 2 (  3.271 ms  5.694 ms  6.287 ms
$ traceroute
traceroute to (, 30 hops max, 60 byte packets
 1  my.router (  3.307 ms  3.772 ms  3.752 ms
 2 (  49.445 ms  48.618 ms  48.193 ms

It'll do for now. I will look into a better solution for the load balancing.

Wanting to leave a comment?

Comments and feedback are welcome by email (

Tags: networking hacks

Blog IndexPosts by TagHome

Copyright 2007-2022 Aaron S. Jackson (compiled: Sun 2 Jan 00:24:10 GMT 2022)