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25 Gigabit Linux internet router PC build

michael.stapelberg.ch

11–20 of 359 posts

Re: 25 Gigabit Linux internet router PC build

#11
post #4

I'm always amazed by people who don't bat an eye on the perspective of having a home server, sucking up electricity 24/7. In this case replacing a typical router (which consumes like a lightbulb), with a full-fledged PC (probably consuming like x100 the power). I guess some people around the world have quite cheap utility bills! For me, it's either a Raspberry Pi type of power consumption, or else a server that only…

I think if the OP uses this only as a router it is indeed a waste of power. What I would probably do is also use it as nas/workstation by using virtualization, SR-IOV is now pretty standard on these cards.

I’m using the machine also as a server, so it replaces 2 existing devices. In terms of power consumption, it’s likely only a small increase, if at all.

Re: 25 Gigabit Linux internet router PC build

#12
Here I am having just had FTTH installed, but capped to a mere 160 Mbps. The main problem I am having is not the router (which handles such a "slow" speed fine) but the wiring throughout the house. It's all copper ethernet and because of the lengths and the fact that the runs must go parallel to some mains electricity cables, it tops out at 100 Mbps. I hope the poster has already put fibre around his house.

Re: 25 Gigabit Linux internet router PC build

#13
post #12

Here I am having just had FTTH installed, but capped to a mere 160 Mbps. The main problem I am having is not the router (which handles such a "slow" speed fine) but the wiring throughout the house. It's all copper ethernet and because of the lengths and the fact that the runs must go parallel to some mains electricity cables, it tops out at 100 Mbps. I hope the poster has already put fibre around his house.

“The poster” (hey!) has put fiber around their house :)

https://michael.stapelberg.ch/posts/2020-08-09-fiber-link-ho...

https://michael.stapelberg.ch/posts/2021-05-16-home-network-...

Re: 25 Gigabit Linux internet router PC build

#14
post #4

I'm always amazed by people who don't bat an eye on the perspective of having a home server, sucking up electricity 24/7. In this case replacing a typical router (which consumes like a lightbulb), with a full-fledged PC (probably consuming like x100 the power). I guess some people around the world have quite cheap utility bills! For me, it's either a Raspberry Pi type of power consumption, or else a server that only…

[deleted]

Re: 25 Gigabit Linux internet router PC build

#16

Well, hate to tell you but you'll be limited 10Gb/s with these Intel cards because they require FEC.

You mean 10 Gbit/s per link? Even on the 25 Gbit/s card?

Where can I read more about FEC (forward error correction?) and how that affects link speeds?

Re: 25 Gigabit Linux internet router PC build

#17
What is the practical consumer (or even SME) use of a 10 or 25G connection?

As a consumer I’d definitely get it for the fun of it, but what is the point in reality?

We’ve just launched an ISP a couple of weeks ago here in Europe. Peak bandwidth use is about 3mbps per customer, and customers will download the same amount of data regardless of their plan.

I acknowledge this could be lack of imagination on my part, but the progression of bandwidth availability seems to be wildly outstripping demand (at least when it comes to fibre deployments).

Perhaps someone living in SF with a 25G connection can disabuse me of this notion.

Re: 25 Gigabit Linux internet router PC build

#18
post #11

Earlier quoted context omitted.

I think if the OP uses this only as a router it is indeed a waste of power. What I would probably do is also use it as nas/workstation by using virtualization, SR-IOV is now pretty standard on these cards.

I’m using the machine also as a server, so it replaces 2 existing devices. In terms of power consumption, it’s likely only a small increase, if at all.

Also, the user can use his freedom to build and do whatever wished for. This tone of you shouldn't do this because some COTS is available sounds very commercially driven. People have the power to create another Google, we are not powerless.

Re: 25 Gigabit Linux internet router PC build

#19
post #4

I'm always amazed by people who don't bat an eye on the perspective of having a home server, sucking up electricity 24/7. In this case replacing a typical router (which consumes like a lightbulb), with a full-fledged PC (probably consuming like x100 the power). I guess some people around the world have quite cheap utility bills! For me, it's either a Raspberry Pi type of power consumption, or else a server that only…

> I guess some people around the world have quite cheap utility bills! Or they work at Google and don't really have to care. Electricity is not particularly cheap in Switzerland, but not particularly expensive either (nothing like Germany for instance). If running a home lab is your hobby, why not. There are plenty of hobbies that are a lot more expensive.

The machine's clearly massive overkill for routing. Another commenter points out it typically runs around 50w - and the OP says they're also using it as a server in this thread.

Re: 25 Gigabit Linux internet router PC build

#20
One thing I've run into when building my own 10gbps router that I didn't see mentioned - you probably need to disable power saving / frequency scaling. The handling of packets is done in software, so when you start a download and the flood of initial data comes in at 10gbps, your CPU will still be running at 600 MHz and unable to keep up. It ramps up within 5-50 milliseconds depending on CPU, but for a TCP download the sender will have already interpreted the dropped packets as congestion and reduced their upload rate.

You can monitor this with ethtool stats to see how many packets the NIC dropped due to host buffers being full.

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