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Linux and Multiple Internet Uplinks: a New Tool
New submitter Alessandro Zarrilli writes: Linux has been able do multipath routing for a long time: it means being able to have routes with multiple gateways and to use them in a (weighted) round-robin fashion. But Linux is missing a tool to actively monitor the state of internet uplinks and change the routing accordingly. Without it, from a LAN perspective, it's like having a RAID-0: just one uplink goes down and all of your LAN-to-WAN traffic goes down too. Documentation and examples on the subject are lacking; existing solutions are few and deeply integrated in firewall/routing specific distributions. To address these issues, a new standalone tool was just released: Fault Tolerant Router. It also includes a complete (iptables + ip policy routing) configuration generator.
Think it was:
http://www.ssi.bg/~ja/
Seems to still be updated.
OpenWRT package mwan3 has similar functionality without the complication of multipath.
http://wiki.openwrt.org/doc/ho...
There's a lot of multipath-related work being done right now, at the IETF, within OpenWRT, and independently.
We've been working on providing multiple routes automatically (disclaimer -- I'm a co-author). As to actually making use of the multiple routes, the solution that currently works best is MP-TCP, a set of kernel patches that allows TCP to use multiple routes simultaneously, with no modification to applications. Other solutions are SHIM6, which works below the transport layer, and Multipath Mosh, which works at the application layer.
I'm pretty confident we'll be able to have most of this stuff enabled by default in mainstream Linux distributions by the end of the year.
Ruby is a scripting language like Perl or Python. Rails is the "hipster web 2.0 app", which is a library (framework) for Ruby.
Perl Programmer for hire
It's really a glorified bash script..and it doesn't actually require any ruby gems to run.
It's just pinging a configurable IP to test specific outbound connections and when an interface goes up or down it resets the routing table...nothing especially fancy.
Link aggregation works at layer 2 (e.g. Ethernet). Basically, make multiple cables between 2 devices look like a single one.
Multipath routing works at layer 3 (e.g. IP), you can send outbound packets to multiple routers for further forwarding. It works when there are "real" routes between the hosts (i.e. not behind NAT).
This is one step beyond that, since it also does connection tracking and will work with outbound port NAT, so you can have a private network connected to multiple ISPs.
"National Security is the chief cause of national insecurity." - Celine's First Law
https://github.com/drsound/fault_tolerant_router/blob/master/fault_tolerant_router.gemspec
At this time it installs at least one gem, and it looks like it's for sending mail (notifications). And that gem might have dependencies of its own.
Given time, and enough feature creep, this project very wall may require more gems down the line.