Cisco 3750G Fan

[JonnyBoy]

I was just wondering if anyone has any experience with getting quieter Cisco fans at all? Currently, I have this switch and the fan is insanely loud. I won't be using the POE function except for one port. I've currently disabled the fan. My questions are:

1) Will having the fan disabled cause any issues if I only use POE on one port?

2) What options are there for other fans? I'm not sure if the fan is a unique to Cisco one or not.

This is what the motherboard looks like:

And this is a better look at the fan:

 

[rune-san]

3750 switches (with a partial exception of the X) are ridiculously inefficient. The 3750-E that I have pulls 70 watts of power just sitting on with nothing plugged in. You cannot run the switch fanless (I tried). It will reach thermal shutdown eventually, as the heatsinks are not nearly large enough to account for a passive airflow environment. Blower fans are not quiet, but are designed for applications where high static pressure is needed. Because the application for blower fans tends to be much more specific, you'd have a tough time finding a good fit. The switches have RPM monitoring and thermal probes, and if either gets too out of hand, the switch will alarm.

If noise is a really critical issue, I'd either try to move the switch to a different area, sound deaden the cabinet it's in, or look into one of the numerous, more modern, far more efficient gigabit switches that are on the market. A case could be made that Managed Gigabit switches were a big deal 10 years ago, but said switches are commodity now, and far more efficient.

 

[JonnyBoy]

Unfortunately, I agree with both of you about unplugging the fan which is really too bad.

If noise is a really critical issue, I'd either try to move the switch to a different area, sound deaden the cabinet it's in, or look into one of the numerous, more modern, far more efficient gigabit switches that are on the market. A case could be made that Managed Gigabit switches were a big deal 10 years ago, but said switches are commodity now, and far more efficient.

Noise is definitely an issue as well as efficiency and not producing heat. I really don't need a L3 switch, but I primarily wanted to use the Cisco one because of Netflow data. I also have a pfSense router but as far as I can tell there's no up to date packages to get Netflow like data.

Are you able to suggest any other quieter, more efficient L2/L3 switches that would give me Netflow data?

 

[rune-san]

Netflow can be difficult because it can be done in a bunch of different ways, with varying levels of granularity and support. One question is if you specifically need Netflow (a Cisco standard), or if you can use IPFIX via sFlow (which is industry standards based). I also didn't know if you were using 24 port or 48 port switches, and whether or not stacking was necessary.

Netflow and sFlow heavily depend on offloading hardware to get their collection job done. This can be done in-switch, on dedicated hardware, or often to lesser extents using other systems.

pfSense has the old softflowd implementation, and VMware has IPFIX support if you use their virtual distributed switch (vDS).

A description about the topology of the network you're using this switch in might help. If this is really where all the traffic you want to monitor goes, then it's probably the best place to do collection. In which case, you'll have a difficult time finding a truly quiet switch. Flows are still very much a resource intensive process to perform at wire-speed.