Cisco 2960 PoE setup

Yes, I was thinking of switches etc. I’ve been looking into whether my ZTE 4G hub could be improved by a different 12v power supply. That seems to be one of the latest trends.

Just to echo TAPP’s thanks. You have a way of making impenetrable teccy stuff seem intelligible (or almost intelligible) to the completely clueless like myself.

Electricity prices are falling, the cap is reducing.

So say for example someone had a spare managed Cisco 3650 (previously used to improve 272) and to scratch an itch might try and reintroduce with a Ubiquiti Flex mini powered by POE (30 quid, why not….) :smile:

In this hypothetical situation all lounge network devices (NAS, NDX2, SkyQ) would currently be connected directly to ISP hub with CatSnake cabling.

I am guessing the way ahead here would be to daisy chain from hub to 3650 to Flex for NDX2 then have the long cable run to the device, with NAS/Sky still connected to ISP hub, or maybe NAS to Cisco?

Our previous experiments with NDX2 and separate DAC didn’t find any SQ difference with and without switch, but maybe POE is the secret sauce :laughing:

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I don’t think you’ll find a difference. An ndx2 with seperate DAC effectively eliminates any considerations on the network other than it needs to provide reliable Ethernet and connected services…. At least that is what I found as well.
So it then becomes more about having physical distance (electro magnetic distance) between relatively electrically noisy network equipment and sensitive audio replay equipment. A PoE powered switch should be a step in the right direction here… but this is then not about networking, just local electrical environment.

In that case we won’t bother, since the hub is already well away from NDX2.

I’m affraid it certainly is your imagination. Ethernet switches have zero impact on sound quality, unless they’re dropping packets and causing buffering.

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I would disagree, I certainly noticed a difference in the sound when going from a Cisco SG110D 110 Series 5-Port Unmanaged Network Switch to a Cisco C2960C-8PC-L switch and then again when I added a English Electric 8Switch.

If you do a search using ‘Ethernet Switch’ you will fine 50+ threads and many comments from users stating an impact on the sound of their systems using different switches.

With a Muso, very certainly. Not with a much more resolved system.

Hi, switches or any network equipment can affect certain directly connected streamers … it is not really all about network performance …and a layer 2 switch would drop frames if anything…. It’s the out of band perturbations like serial clock phase noise and common mode noise… these noise sources can couple into certain streamers and affect performance through noise modulation…. But these noise sources are not directly related to network data. Clearly direct fibre to the streamer removes common mode noise, but not phase noise.
Wifi also removes common mode noise.

Other consideration of higher quality/more capable switches is that they handle IGMP snooping, which means certain multicast network data noise on your LAN, which is increasingly used in home networks, is correctly filtered from your streamer’s network processing circuitry (potentially adding digital noise- think FLAC vs WAV) . Cheap consumer and all so called audiophile switches which are very basic devices of the ones I have seen, don’t support this capability.
So yes switches directly connected to a streamer can affect resultant performance… yes we are talking very subtle, but that is the calibration often used in consumer Hi-Fi.

Now there are no absolutes here, because I maintain an optimum and well designed streamer and DAC (typically separate in my experience) implementation can sufficiently decouple these noise sources so there is no noticeable impact on audio, even on a super-resolving system with planar headphones.


Just about to reply to your post when I was saved by this timely salvo from Our Man in Suffolk.

Why waffle on vaguely about ‘network noise’ (me) when you can casually reference ‘out-of-band perturbations’ with such authority. Cheers Simon!

The good news is I’ve finally managed to console into my Ciscos, so I’m excited to try IGMP snooping, mostly because I find the phrase amusing.

Hoping for some more subtle (but non-imaginary) gains…

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LOL - yes I think it was a term that was used tongue in cheek way back when these techniques were being developed and it stuck. It really means monitoring and acting upon


IGMP snooping is just a way for switches to identify multicast groups. Turning it on or off has absolutely nothing to do with audio quality of a steam as the audio isn’t played directly from ethernet packets. It has to be decompressed, decoded, buffered. In the end of it all the audio goes into a ring buffer and it is played very precisely by your streamer.

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I would be interested to hear your view/analysis on some sorts of digital stream re-clocker and electrical noise isolator like the InnuOS PhoenixNet and others?

When a teacher teaches a teacher….let’s the battle begin :cup_with_straw:

That’s right, snooping services generally monitor and act. With IGMP snooping the port is monitored by the switch system and if it sees an IGMP join instruction to a multicast group address, it allows that group IP address along with device’s unicast IP address to pass through unfiltered on the port. Mind you be careful not to conflate this with TCP audio data and the integrity or ‘quality’ of that data.

Now the bit that is relevant here, is that the port filters other group address traffic from that segment so the router doesn’t have to receive the frame, decode it and then act on it to see whether to discard or not. On streamers, certainly with DACs built in it is usually preferable to remove unnecessary digital Ethernet and data decoding on the Ethernet port. Some TV services and many home automation services use multicast groups IP addresses. Now yes some of group IP address ranges should never be filtered, but others can and should be for optimum performance.

Of course, as I said above, this has nothing to do with audio data or ‘sample’ data, or the integrity of that data, this is about reducing unnecessary overhead processing in your streamer network electronics which could be prevalent if you have multicast ip addresses in use on your home LAN, and the chances are you do. A good commercial grade switch like the venerable Cisco 2960 can report all the group addresses it sees active,. If you can hear the difference between FLAC and wav decoding I say you are more likely to hear the effects of unnecessary network frame decoding from your streamer.

I think I have found over the years on this forum and elsewhere, even in my professional work, some people may find this aspect a little confusing. Ethernet is relatively straightforward with multicast group addresses ultimately, but wifi can be quite ‘interesting’

Hmm, I didn’t realize IGMP snooping needed to be enabled via console, thought it was enabled in default mode. If that’s the case I may need to get the console cable out and check the setting.

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I’ve never come across any managed switch that disables IGMP snooping by default.
If in doubt, just do a reset to the factory settings.

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Which device are you referring to? If you are talking about the traditional Cisco catalyst switches like the 2960 and 3560, then IGMP snooping is enabled in default configuration, but dhcp snooping is not… which is about preventing rogue dhcp servers being added into a network, and not relevant to the discussion here. Really you would only likely disable IGMP snooping for some sort of interoperability issue with network applications.

If you want to see what multicast group ip addresses exist on your home network, then you will need to login to the console either via a console lead, or use a set up loop back ip address to connect to.

Yeah, 2960 Catalyst PD switches in a POE configuration. I was responding to a previous comment about consoling to turn on the IGMP feature. I was under the impression that feature is on by default and I’m running both switches in default configuration. Appreciate the confirmation, Simon.

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