So as not to pollute an ethernet cable thread too much I’ll move to here…
The manual is the Business 250 Series (CBS250) - I assume that includes the SG250? If not it suggests it might be a limitation of your particular product
Cisco’s product naming is a topic on its own! I think even the CBS series is now superseded by the Catalyst 1200/1300 now… SG250/SG350 were the switches replaced by the CBS I think…
I agree on naming - I’ll take your word on it for the sequencing
I’m struggling to get ssh running… Mac OS and the switch are on different ciphers… most of the documentation assumes CLI access.
they parameter should be negotiated .. assuming its SSH v2. MAcOS doesn’t support SSH v1 any more.
You know how to delete the old key pair in MacOS - just in case things have changed like IP addresses from when it was used last.
rm ~/.ssh/id_rsa ~/.ssh/id_rsa.pub
replace id_rsa with the key from your Cisco SSH connection last time from MacOS terminal
or to delte all SSH keys
rm -rf ~/.ssh/id_*
I’m in now…
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No idea about MacOS but on Windows 11 I have to specify a few options to get a connection to our (older/EOL) 2960C. Thought I would add for posterity….
Options being passed are:
-oKexAlgorithms=+diffie-hellman-group1-sha1
-oHostKeyAlgorithms=+sha-rsa
-m hmac-sha1
-c aes256-cbc
If you just ssh root@IP the command line tool on windows fails on 4 things in sequence and gives you the options offered, so not hard to divine.
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ssh -o HostKeyAlgorithms=+ssh-rsa
And then your id@ip address fixed it on MacOS.
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Newer OS don’t offer these older ciphers by default for security reasons as they have been superseded.
But our EOL switch can’t get a newer iOS version so is stuck in dark ages.
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if you are in CLI you might want to see if you can enable telnet. Not secure in live commercial setups - but fine for home use - its as secure as UPnP DLNA 
CLI via ssh is working so happy to leave it with that! Was there anything you wanted me to run?
I was looking at the guide for your switch
I would enable the Global parameter for Energy Detect Mode
I would enable the Global parameter for Short Reach.
I would enable full link negotiation on the particular port
I would then enable Energy Detect for your particular port
I would then enable Short Reach for your particular port.
I would then ensure the port settings are applied.
According to the manual that should work, if not it might be a bug with the firmware .
Command line may give you error feedback if you try and do something that trips the switch up.
The manual stipulates the global parameters for Short Reach in Port Management must be enabled for the port settings of Short Reach to take effect.
https://www.cisco.com/c/dam/en/us/td/docs/switches/lan/csbms/250_/2_5_7/Sx250_2_5_7_CLI.pdf
Section 20.
The cli commands required are listed there
green-ethernet short-reach
switchxxxxxx(config)# interface gi1. (Or which ever interface)
switchxxxxxx(config-if)# green-ethernet short-reach
#show green-Ethernet
**Edit… I found it…. ** for that switch type… it states
The VCT length check can be performed only on a copper port operating at a speed of 1000
Mbps. If the media is not copper or the link speed is not 1000, Mbps Short-Reach mode is not applied.
So for that model you are out of luck.
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I have a Cisco 2960G. All I did was reset it to factory defaults. I use a Mac and bought a console cable with a USB-C connector.
Here’s what I used to get it connected:
- Plug the cable into your mac and switch
- In terminal, type: ls /dev/tty.usb* (you should have an entry there for the device. Mine is /dev/tty.usbserial-AL00****)
- Run this command with your device name from the ls command above: /dev/tty.usbserial-AL00**** -f 9600,cs8,-parenb,-cstopb,-hupcl
- To exit, Ctrl-A, then type ‘k’ and it will close the connection.
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Thanks Simon, at least I know I wasn’t going mad with it not enabling. Interestingly if you look in the CLI guides even for the very latest switches at this level (1300X), it explicitly says that VCT will only function for gig ethernet and won’t enable short reach. The GUI guides are much more vague.
Looking at what Cisco sell now, it seems you either get a 1300 class switch, or you’re into the main 9200 range, which would be a bit of overkill for home use plus very expensive, and from what I can see, the latter only supports full 802.3 EEE, so needs I think support from the remote device for the best efficiency anyway.
I think Short Reach was a Cisco specific thing which is why if it is enabled, the 802.3 EEE stuff has to be disabled.
So, to get the maximum benefit from energy saving, it would seem the best route forward, if the NP800 supports it, would be the enabling of 802.3 EEE features, probably via a toggle in the app. Whether this helps or not is something for Naim to look into if they think it’s worth the effort I guess.
Otherwise, ignoring some of the boutique stuff, then to me it makes sense to try and minimise as much traffic as possible on the network hitting the streamer, and as I have a Sonos system, and some smart devices that appear to use multicast, this is definitely worthwhile. I already know misconfiguration of this can result in enough traffic to overwhelm my LG TV’s 100M interface.
On the energy front, my default setting on ports is to enable the switch to put ports into sleep mode if the attached devices aren’t on. If nothing else it should mean less overall background noise around the network than if all ports were always on. The 802.3 stuff is on by default, but from what I can see, not many home devices seem to support it.
Hi Ian, no Green Ethernet is not Cisco proprietary .. but was introduced as a standard after 802.3az was ratfied… so doesn’t appear in EEE, but builds on it and is a superset. Green Ethernet is a more recent development as a standard.
Green Ethernet includes new features like Short Reach, improved chip design efficiency and also wireless aspects.
Major hardware manufacturers that support all or part of the Green Ethernet standard include
Edge core Networks
Zyxcel
Broadcom
Microchip Technology
Cisco and a few others.
It appears Green Ethernet includes certain features that reduce network noise and cross talk in cable looms.. as compared to EEE… hence its relevance here for audiophiles potentially.
However EEE is not always compatible with Green Ethernet on some hardware so with some chipsets you choose one or the other.
Blimey, I know I am not the brightest guy in the world, but I have never read a thread where I understood so little of what was being talked about!!! 
No probs with my BT router into my NDX2 
Yep this is a specific thread that was started away from another… so it’s very particular … unless you work in the relevant industry it might not mean much!
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Thanks Simon, I don’t feel too bad now!
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