Graham Sutherland / Polynomialspent a while debugging why my computer can't reach certain IP addresses on my LAN.
the problem randomly went away.
I hate this.
it's working fine now and I don't like it
it wasn't the firewall rules, it wasn't the firewall zone type either. IPs are on the same subnet. can hit the exact same IPs from a different host. wireshark shows outbound SYN / ping packets on the expected interface, with the correctly resolved MAC, but no response. router firewall rule monitor shows no packets dropped associated with either host. baffling.
I checked the lease table and the historical DHCP logs, no other device has ever leased the same IP (and in fact it's on a static lease anyway). arp cache on all hosts, including the router, showed correct entries. no clue.
AMS@gsuberland Either end on wifi? I've had weird issues where the packets were fine on the wire, but never made it over the air because the WAP didn't think they should. Rebooting the WAP fixed it.
🇺🇦 haxadecimal 🚫👑@AMS @gsuberland
My TP-Link EAP-660HD access point works great most of the time, but every six to eight weeks, it starts misbehaving in various ways, and has to be rebooted. I suspect that it develops a memory fragmentation problem. I can ssh in as admin to a shell, but they've got it locked down and I can't run any useful diagnostic tools because I can't get root.
It supports scheduled reboot from the Omada Controller, but I don't run that.
My TP-Link EAP-660HD access point works great most of the time, but every six to eight weeks, it starts misbehaving in various ways, and has to be rebooted. I suspect that it develops a memory fragmentation problem. I can ssh in as admin to a shell, but they've got it locked down and I can't run any useful diagnostic tools because I can't get root.
It supports scheduled reboot from the Omada Controller, but I don't run that.
@brouhaha @gsuberland I just bounce power on the PoE switch port. Joys of running a real managed switch.
@AMS @gsuberland
I have a networked box that can do that around here _someehere_. I used to need that on a VDSL2 modem, before I switched to GPON. I'll try to find the thing.
I have a networked box that can do that around here _someehere_. I used to need that on a VDSL2 modem, before I switched to GPON. I'll try to find the thing.
@AMS @gsuberland
Found it. Aviosys IP9258TP.
It's web interface sucks. I'll try SNMP.
I was looking at the specs for the Trendnet TPI-06, a current product that does the same thing (4 outlets, wired IP control). It doesn't have SNMP or a REST interface, despite Google AI claiming that it does. That's presumably because they want you to pay $$$ for their cloud management. No f#@&ing way I'm doing that.
@AMS @gsuberland
Given how much the remote-controlled PDU products and market suck, and that it's such a simple concept, I'm tempted to design a product and enter that market. Probably would be a 1U, 4- or 8-port with 10/100 Ethernet. 120/240V, max 15A. Could add voltage and current measurements for a fancier version.
Do European countries require both hot leads to be switched?
Given how much the remote-controlled PDU products and market suck, and that it's such a simple concept, I'm tempted to design a product and enter that market. Probably would be a 1U, 4- or 8-port with 10/100 Ethernet. 120/240V, max 15A. Could add voltage and current measurements for a fancier version.
Do European countries require both hot leads to be switched?
@brouhaha @gsuberland EU is mostly 230/400 three phase, not split phase 120/240 like US residential. The 230 is hot and neutral, just like residential 120 in the US.
@AMS @gsuberland
Thanks! Somehow I was of the impression that residential was two hot, no neutral. I'm not sure where I got that idea.
Thanks! Somehow I was of the impression that residential was two hot, no neutral. I'm not sure where I got that idea.
@AMS @gsuberland
I guess I was most likely confusing it with US residential 240V, which is two hot and (often) no neutral.
I guess I was most likely confusing it with US residential 240V, which is two hot and (often) no neutral.
1000millimeter@brouhaha @AMS @gsuberland But we have plugs (german Schuko, 2pin Euro, italian plug...) that are not polarized and can be plugged in either way, so it's better switching both wires.
@1000millimeter @AMS @gsuberland
Makes sense! Thanks for pointing that out.
It's not uncommon for the 120V outlets in USA to have hot and neutral swapped, so it's better for here, too. Originally the US two prong outlets were not polarized, but code has required them to be polarized for a long time now.
Sadly, it also sometimes occurs in USA that ground and neutral are swapped, which is even more dangerous.
When I move into a new place, I always test all of the outlet wiring.
Makes sense! Thanks for pointing that out.
It's not uncommon for the 120V outlets in USA to have hot and neutral swapped, so it's better for here, too. Originally the US two prong outlets were not polarized, but code has required them to be polarized for a long time now.
Sadly, it also sometimes occurs in USA that ground and neutral are swapped, which is even more dangerous.
When I move into a new place, I always test all of the outlet wiring.
@1000millimeter @AMS @gsuberland
Originally the prongs were identical. To polarize them, they made one wider, and the corresponding slot of the receptacle wider.
Even grounded outlets here have the polarization, since many products still use non-grounding plugs. IIRC, if such devices are double-insulated, they are allowed to have a non-polarized plug, but e.g. lamps using Edison-base bulbs are not.
People routinely swore at polarized plugs when trying to plug them into old receptacles.
Originally the prongs were identical. To polarize them, they made one wider, and the corresponding slot of the receptacle wider.
Even grounded outlets here have the polarization, since many products still use non-grounding plugs. IIRC, if such devices are double-insulated, they are allowed to have a non-polarized plug, but e.g. lamps using Edison-base bulbs are not.
People routinely swore at polarized plugs when trying to plug them into old receptacles.
@brouhaha @AMS @gsuberland Ph and maybe, if not much more effort, if you go for 16 instead of 15 Amps. This is was Schuko (and the french polarized variant of it) is rated for and most circuit breakers here are rated.
Erin 💽✨@brouhaha @1000millimeter @AMS @gsuberland Belgium is split-phase style 2 hot, no neutral, but they’re a bit unusual
@brouhaha @erincandescent @gsuberland @AMS Allegedly this exists in a few old power net areas in some big cities like Berlin in germany as well, but it's rare.
@brouhaha @erincandescent @gsuberland @AMS (It's not split phase. It's three phase AC power with 127/230V then.)
gunstick@1000millimeter @brouhaha @erincandescent @gsuberland @AMS there are 120V line in europe somewhere? Wow!
And isn't the relationship between phase/neutral and phase to phase √3? So voltage in US would be 207V?
As in Europe between 2 phases you have 240√3=415V
Edit:
Ah oh, it is the same phase split in 2. I have never seen that anywhere in Europe.
https://en.wikipedia.org/wiki/Split-phase_electric_power
@gunstick @brouhaha @erincandescent @gsuberland @AMS I've never seen in person, but allegedly those are some local nets where in early day of electrification, it was a three-phase AC power with 127V to neutral and 220V phase to phase. So when it was harmonized to 220V, you could just use two phases but leave the public network untouched. Some of this may have survived in residential areas, where you normally don't have appliances that use 400V three phase.
@gunstick @brouhaha @erincandescent @gsuberland @AMS If you don't have an elevator (unlikelky in old building) or a 3 phase heat pump (also not very likely until a few years ago), the only appliance to use 3 phases in a household normally is the electric stove - but that also is only multiple 230V consumers distributed over the three phases and can also be operated on a single phase, or in such a system between two phases.
@gunstick @brouhaha @erincandescent @gsuberland @AMS
Most of europe was 220/380V and UK was 240/415V. Around 1990 it was harmonized to 230/400V all over europe.
@gunstick @brouhaha @erincandescent @gsuberland @AMS And yes, North America in residential buildings mostly has split phase with 120/240V. I believe they mostly have 3 phase on the kV side of the power grid, but the end transformer are only single phase on the primary side and split phase on the secondary.
However, as far as I know they sometimes have 120V three phase, then you have 207V between phases. Larger household machines like stoves or tumble dryers can operate both 240V or 207V.
However, as far as I know they sometimes have 120V three phase, then you have 207V between phases. Larger household machines like stoves or tumble dryers can operate both 240V or 207V.
@gunstick @brouhaha @erincandescent @gsuberland @AMS
And then there is the high-leg delta, when they want to have both, 120/240V split phase AND 3-phase AC: https://en.wikipedia.org/wiki/High-leg_delta
And to be honest. I think generally using 3-phase is the better system.
datenwolf@1000millimeter @gunstick @erincandescent @gsuberland @AMS
Yes, three-phase delta distribution. Sometimes residential "last mile" is only two phases to a neighborhood, with the phase balancing done between neighborhoods.
Yes, three-phase delta distribution. Sometimes residential "last mile" is only two phases to a neighborhood, with the phase balancing done between neighborhoods.
@brouhaha @gunstick @erincandescent @gsuberland @AMS And then there is SWER 🙃
