Have you noticed an interesting twist in the ICMP Redirects saga: operating systems of some network devices might install redirect entries and use them for control plane traffic – an interesting implementation side effect of the architecture of most modern network devices.
A large majority of network devices run on some variant of Linux or *BSD operating system, the only true exception being ancient operating systems like Cisco IOS1. The network daemons populate various routing protocol tables and compute the best routes that somehow get merged into a single routing table that might still be just a data structure in some user-mode process.
When I recorded the first podcast with Thomas Graf we both found it so much fun that we decided to do it again. Thomas had attended the NetDev 1.2 conference so when we met in November 2016 we warmed up with What’s NetDev and then started discussing the hot new networking stuff being added to Linux kernel:
I find the topic area of SDN and NFV a bit overwhelming in terms of information, particularly the NFV bit.
NFV is a really simple concept (network services packaged in VM format), what makes it complex is all the infrastructure you need around it.
Robert Graham published another great blog post explaining why you need user-space handling of network traffic for multigigabit performance on x86 servers. A must-read if you’re interested in performance of software-based packet forwarding.
Need product details? I collected some performance data points in the NFV webinar.
One of the participants of the Carrier Ethernet LinkedIn group asked a great question:
When we install a virtual-router of any vendor over an ordinary sever (having general-purpose microprocessor), can it really compete with a physical-router having ASICs, Network Processors…?
Short answer: No … and here’s my longer answer (cross-posted to my blog because not all of my readers participate in that group).
I was asked to do a presentation at the recent Slovenian NOG (SINOG) meeting. I did an SDN one at the previous meeting, making NFV the next obvious choice… but I decided to put an interesting spin on it and focused on virtual routers.