Recently I wanted to look at the structure of sFlow packets. Of course I can read the specs, but it’s often easier to look at some real packets. So I set up a simple network, configured sFlow, created some traffic across the network, and used tcpdump to capture the sFlow packets.
(Read more...)A year ago I published a table of New Zealand ISP IPv6 support. At the time support was fairly poor. I’m pleased to report that things have gotten better over the last year. There has also been a very pleasing uptick in DNSSEC support.
(Read more...)Brocade tightened up some SNMP settings with NOS 6.0.x. This improves security, but it also means that you will need to modify your configuration if you upgrade. If you don’t, SNMP won’t work, and you’ll get errors with BNA/Nagios/Cacti/etc. Here’s the changes, and how to get SNMP working with NOS 6.0.x. NB This applies to [VDX Data Centre switches](http://snmp-server contact “Field Support.” snmp-server location “End User Premise.” snmp-server sys-descr “Brocade VDX Switch.” snmp-server community ConvergedNetwork snmp-server community OrigEquipMfr rw snmp-server community “Secret C0de” rw snmp-server community common snmp-server community private rw snmp-server community public snmp-server user snmpadmin1 groupname snmpadmin snmp-server user snmpadmin2 groupname snmpadmin snmp-server user snmpadmin3 groupname snmpadmin snmp-server user snmpuser1 snmp-server user snmpuser2 snmp-server user snmpuser3). Other product lines have different configuration.
(Read more...)I loathe MRTG graphs. They were cool in 2000, but now they’re showing their age. We have much better visualisation tools available, and we don’t need to be so aggressive with aggregating old data. I’ve been working with InfluxDB + Grafana recently. Much cooler, much more flexible. Here’s a walk-through on setting up InfluxDB + Grafana, collecting network throughput data, and displaying it.
(Read more...)I work from home these days. Therefore it’s important that I have a decent desk setup. My previous setup was pretty crappy, but I only worked from home part-time. I’ve been using a standing desk at home, and wanted to move to a sit/stand model for full-time use. Here’s what I did.
(Read more...)Brocade Network Advisor (BNA) has a REST API for accessing Fibre Channel-related data. The documentation includes a sample Python script showing how to connect to the API to retrieve Fabric info. The script given only works with Python 3.x. It’s also a pain to copy out of the documentation as you end up with a few extra characters in there. Here’s a version that will work with Python 2.7. I’ve also made a few other modifications - in this one, you can set the BNA IP, Username & Password at the top of the script. I’ve also made it PEP8-compliant.
(Read more...)This article is Part 10 in a 12-Part Series.
Apple’s 2015 WWDC event included a great session on IPv6 & TCP changes coming with iOS 9. There is a related post to the IETF v6ops mailing list here. The new IPv6 hotspot is very interesting to me. These are my notes on how hotspot functionality can work with IPv6, and no NAT.
(Read more...)The Docker/shipping container metaphor is overdone. I don’t think people have fully thought through what it might mean if containers do the same thing to computing as they did to shipping. Are we prepared for hipsters taking over derelict data centers?
(Read more...)This article is Part 9 in a 12-Part Series.