2022-05-12 Generations of Netgear switches and interface names
In my time at Utrecht University computer science I wrote a script to search Cisco switches for a given ethernet address and respond with the port. This could be used to trace things on the network, which helped on incidents in progress. This script was based on the typical things Cisco switches do with vlan CAM table lookups and the best implementation. CAM stands for Content Addressable Memory: memory optimized for doing lookups by certain content. In the case of a network switch a 6-byte MAC address plus 2-byte vlan id will be used to do a lookup of the 2-byte interface number where it was last seen, and this lookup is done in hardware. This CAM table is accessible via SNMP, and the funny part is the MAC address for the lookup is also encoded as SNMP identifier. I could get the whole CAM table via snmpwalk but as I only want to lookup 1 MAC address it is way faster to go directly from MAC address to interface number. After that the interface number is translated to an interface name and that name is usually something recognizable to a network engineer. When I started using managed switches at home from Netgear I adapted the script at home and enhanced it for Netgear switches. I recently added a third netgear switch when upgrading the fiber to the shed and I updated the script to learn about the new switch. I noticed the interface names are quite different over the generations of netgear switches. The oldest switch is a Netgear GSM7224. The interface name from a query is "Unit: 1 Slot: 0 Port: 15 Gigabit - Level". The second switch is a Netgear GS716Tv2. The interface name from a query is "Slot: 0 Port: 11 Gigabit - Level". The newest switch is a Netgear GS310TP. The interface name from a query is "GigabitEthernet9". The Unit: 1 in the GSM7224 suggests some option for stacking multiple switches, but I can't find any mention of that option in the on-line documentation. The other fun part I notice is interface names never showing the fact that they are actually an SFP interface with an SFP in them. The port status for a port with an SFP is not different from the status for a copper cable at gigabit.
2022-05-11 The fiber to the shed network has been upgraded
I got around to doing the upgrade of the fiber to the shed network I had on my mind today. A friendly network layer 1 engineer had some leftover Cisco SFP modules and the netgear GS310TP and netgear GS716Tv2 switches accepted these without any issue. So the layer 1 network link came up fine. The layer 2 link with vlan support took me a few hours, somehow I managed to get confused with vlan tagging, vlan tagged only frames and the primary vlan id. I haven't done this in a while and I sort of copied the configuration from another port which may be less than optimal too. I had to run through the house a number of times to get the configuration right, wireless devices can't access the managed switches. At least I got the whole configuration working in the end. I think I can add other vlans to the link too (I want the option of a wireless access-point in the shed). Putting the switch, the power supply for the switch, the raspberry Pi, the power injector for the 1-wire measurement network and all network cables and fiber in the plastic box I bought for this work was a bit of work, it just fits (so a wireless access point will have to live outside that box..). But it's all in there and the box is closed again. It's just not airtight anymore with the new holes for power, fiber, network cable, gps antenna cable and 1-wire network. I may need to stuff the holes with foam or something similar to keep insects from crawling into the box. Everything works now and the measurements from the solar inverter are coming in!
2022-05-09 Grafana alerts working again
After reverting to Grafana 8.4.7 for a while because alerts were failing in Grafana 8.5.0 I had a look at the available version today and saw version 8.5.2. I assumed the problem with DataSourceNoData errors was fixed by now and did the upgrade. Indeed the alerts are seeing data fine now and I trust they will work when needed.
2022-04-23 New country in amateur radio: Iran
A notable and rare country in the log today: Iran. I've seen Iranian calls on the air a few times but it is rare. Today I saw EP2C on the air in FT8 in the 17 meter band and got the contact. Confirming it is the next step: they have a QSL manager so I'll have to pay a few euros to get a paper card. Although the call seems active on Logbook of The World.
2022-04-23 Grafana alerts failing in 8.5.0
I installed Grafana from their debian repository, so I get updates via the normal apt update / apt dist-upgrade process. Since upgrading to version 8.5.0 the alerts were all firing because of 'DatasourceNoData' errors. According to Alert Rule returned no data (after upgrade to 8.5.0) #48128 other people are seeing this too. For now I downgraded to version 8.4.7 where things work fine and I'll see if a newer version shows up.
2022-04-20 I passed the morse exam in Belgium
In October 2018 a morse course started at my local radio club under the leadership of Ab PA5ABW. Around March 2020 the people still going strong practising morse thought they had a chance of passing the morse exam in Belgium. But that pandemic happened, borders closed and gatherings of radio amateurs were impossible. Why go to Belgium? The Dutch telecommunications authority does note whether you have 'CW included' or 'CW not included' but there is no exam possibility in the Netherlands. So in the past doing the exam in Belgium, presenting the certificate to the Belgian telecommunications authorities to get it converted to a certificate the Dutch authoritities accepted and converting that certificate to a Dutch 'CW included' note was the way. When there was an option of a Morse exam in April 2022 in Belgium again there was a note the Belgian telecommunications authorities were not willing to do the 'conversion' for foreign radio amateurs who weren't living in Belgium. This seemed to kill the route to get the much coveted 'CW included'. After writing an article about this a suggestion came to 'skip' the Belgian telecommunications authorities and present the Belgian certificate to the Dutch telecommunications authorities. Later there was news from the Veron amateur club: Morse examen doen in België voor een ‘CW included’ aantekening kan nog steeds with a statement from Agentschap Telecom (Dutch telecommunications authorities) stating they would accept the certificate from the UBA club in Belgium at this time. So when that became an option we registered for the exam in Belgium and kept practising. Personally I had to change to using actual pen and paper and not a keyboard because the exam would be using paper! Between October 2018 and April 2022 we practised for about three and a half years. That means I practised morse in one way or the other for almost every day of the week. The three of us went to Diest last Monday and all passed the test. On Tuesday I sent scans of all the needed documents to Agentschap Telecom to get those three letters removed from the amateur radio license document, going from "CW not included" to "CW included".
2022-04-13 First IPv6 sightings at work
Years and years after writing proposals to start doing something with IPv6 at work I noticed the first systems actually having IPv6 connectivity in production networks. Finally getting there! I wonder when workstations will start having IPv6 connectivity.
2022-04-10 A contact with a Brazilian radio amateur in morse on the 10 meter band
As noted before Brazil was a rare country for me on 10 meter until a few weeks ago but it got easier to get those contacts with the 10 meter band getting better due to the changing sunspot cycle. I changed this even more yesterday with a morse contact with PY2ZEA on the 10 meter band. I heard him calling and getting a lot of short contacts into Europe. At first the signal started fading into the noise but about 20 minutes later it came back slowly and with more calling cq for new contacts. I gave it a try and on the second attempt he got my call correctly and we exchanged some messages. More than just a signal report and a call, I told in morse that this was my first morse contact into Brazil.
2022-04-06 I participated in the EA RTTY contest 2022 last weekend
Last weekend was the EA RTTY Contest 2022 edition. At the last moment I decided to participate because I appreciate the contests organized by the Unión de Radioaficionados Españoles. Conditions were good: I made contacts on the 20 meter amateur band Saturday afternoon, on the 40 meter amateur band Saturday evening and even got contacts on the 10 meter amateur band on Sunday morning. Hasn't happened a lot in the last few years: contest contacts on the 10 meter band. Including a contact with a station in Brazil which was a bit remarkable: I had my first contact with Brazil on the 10 meter band only 2 weeks earlier! For most Dutch amateurs Brazil is 'easy' DX, but my antenna points mostly to the East / South. In the end I made 135 contacts which is a nice score for this contest.Read the rest of I participated in the EA RTTY contest 2022 last weekend
2022-04-01 Mention of my igateItems with tag english before 2022-04-01
In 2020 I built an igate: a device for receiving status packets on amateur frequencies and got it succesfully receiving packets and publishing them to the APRS network. Since then the hardware has been in a corner of the radio shack receiving packets, building a good coverage of received packets and doing fine. Today I noticed in Razzies April 2022 a Dutch-language electronic magazine of the Radio Amateurs Zoetermeer a nice mention of 'my' igate:De enige gateway die dapper stand houdt is PE4KH-10: nota bene een iGate naar ontwerp van onze club: een RAZ iGate...or translated: the only gateway still standing strong is PE4KH-10: notably an igate made to the design from our club: a RAZ igate. It's nice to get this mention! The hardware is in the corner of the shack just doing its job and nothing else.