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One network card many rj45 sockets

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  One network card many rj45 sockets mick crane <mick.crane@gmail.com> - 2021-01-19 13:50 +0100
    Re: One network card many rj45 sockets Reco <recoverym4n@enotuniq.net> - 2021-01-19 14:10 +0100
    Re: One network card many rj45 sockets Georgi Naplatanov <gosho@oles.biz> - 2021-01-19 14:10 +0100
    Re: One network card many rj45 sockets <tomas@tuxteam.de> - 2021-01-19 15:00 +0100
    Re: One network card many rj45 sockets Dan Ritter <dsr@randomstring.org> - 2021-01-19 15:30 +0100
      Re: One network card many rj45 sockets Stefan Monnier <monnier@iro.umontreal.ca> - 2021-01-19 16:40 +0100
      Re: One network card many rj45 sockets Dan Ritter <dsr@randomstring.org> - 2021-01-19 17:50 +0100
      Re: One network card many rj45 sockets David Christensen <dpchrist@holgerdanske.com> - 2021-01-19 23:30 +0100
        Re: One network card many rj45 sockets Dan Ritter <dsr@randomstring.org> - 2021-01-19 23:40 +0100
          Re: One network card many rj45 sockets David Christensen <dpchrist@holgerdanske.com> - 2021-01-20 01:20 +0100
            Re: One network card many rj45 sockets Dan Ritter <dsr@randomstring.org> - 2021-01-20 04:30 +0100
    Re: One network card many rj45 sockets Henning Follmann <hfollmann@itcfollmann.com> - 2021-01-19 16:00 +0100
    Re: One network card many rj45 sockets Andy Smith <andy@strugglers.net> - 2021-01-19 16:10 +0100
    Re: One network card many rj45 sockets David Christensen <dpchrist@holgerdanske.com> - 2021-01-19 23:00 +0100
      Re: One network card many rj45 sockets Sven Hartge <sven@svenhartge.de> - 2021-01-19 23:10 +0100

#230837 — One network card many rj45 sockets

hello,
I see that you can get a single network card with 2, 3, 4 connections.
Can you happily make each one on a separate private address block ?
10.0.0.0, 172.16.0.0, 192.168.0.0

mick

-- 
Key ID    4BFEBB31

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#230838

	Hi.

On Tue, Jan 19, 2021 at 12:47:34PM +0000, mick crane wrote:
> I see that you can get a single network card with 2, 3, 4 connections.

They call them "ports" usually. Such things exist for a long time in a
server world, but are infrequent in consumer one.

> Can you happily make each one on a separate private address block ?
> 10.0.0.0, 172.16.0.0, 192.168.0.0

Yes, it's definitely possible - from IP stack point of view each port is
a different network interface.

It'll unlikely be efficient (compared to a managed switch, that is) if
your plan is to use such card as a router - after all you'll need to
copy all the packets to the kernel and back, and that takes time.
But it still going to beat more common DIY combo of two/three USB-Ethernets.

Reco

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#230839

On 1/19/21 2:47 PM, mick crane wrote:
> hello,
> I see that you can get a single network card with 2, 3, 4 connections.
> Can you happily make each one on a separate private address block ?
> 10.0.0.0, 172.16.0.0, 192.168.0.0
> 

I don't know what the purpose is one network card to have multiple
connectors but yes it's possible one network card to have multiple IP
addresses - IPv4 and/or IPv6.

Kind regards
Georgi

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#230841

[Multipart message — attachments visible in raw view] — view raw

On Tue, Jan 19, 2021 at 12:47:34PM +0000, mick crane wrote:
> hello,
> I see that you can get a single network card with 2, 3, 4 connections.
> Can you happily make each one on a separate private address block ?
> 10.0.0.0, 172.16.0.0, 192.168.0.0

You can even put one connection (aka "port") on several networks.

Cheers
 - t

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#230842

mick crane wrote: 
> hello,
> I see that you can get a single network card with 2, 3, 4 connections.
> Can you happily make each one on a separate private address block ?
> 10.0.0.0, 172.16.0.0, 192.168.0.0

My firewall (yes, it runs Debian) has an Intel 4x 1gig ethernet
card in it, as well as the 1 gig port on the motherboard. Each
is completely independent, so I have:

- one connection to the public Internet 
- one connection to my switched network of wifi access points
- one connection to my general wired network switch
- one connection to my remote power switch
- and a free connection for the future.

Each of these has one or more different IP addresses, including
IPv6 on three ports, and packets are routed between them and 
blocked by the firewall.

-dsr-

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#230850

> What is the purpose of remote power switch ?

Probably to turn on the popcorn machine when you're not at home.


        Stefan

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#230855

mick crane wrote: 
> What is the purpose of remote power switch ?

It can turn on and off a set of wall outlets, to which other
computers are attached. In other words, if the firewall is
running, I can power-cycle several other machines.

-dsr-

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#230865

On 2021-01-19 06:22, Dan Ritter wrote:
> mick crane wrote:
>> hello,
>> I see that you can get a single network card with 2, 3, 4 connections.
>> Can you happily make each one on a separate private address block ?
>> 10.0.0.0, 172.16.0.0, 192.168.0.0
> 
> My firewall (yes, it runs Debian) has an Intel 4x 1gig ethernet
> card in it, as well as the 1 gig port on the motherboard. Each
> is completely independent, so I have:
> 
> - one connection to the public Internet
> - one connection to my switched network of wifi access points
> - one connection to my general wired network switch
> - one connection to my remote power switch
> - and a free connection for the future.
> 
> Each of these has one or more different IP addresses, including
> IPv6 on three ports, and packets are routed between them and
> blocked by the firewall.

On 2021-01-19 08:40, Dan Ritter wrote:
 > [The remote power switch] can turn on and off a set of wall outlets,
 > to which other computers are attached. In other words, if the firewall
 > is running, I can power-cycle several other machines.


I assume your Wi-Fi, LAN, and remote power switch interfaces are on 
different network segments (?).


Do you have use-cases that require or benefit from this, or could you 
replace the 4-port NIC with a 1-port NIC connected to a switch connected 
to all of the inside devices (AP's, clients, servers, power gateway, etc.)?


David

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#230866

David Christensen wrote: 
> On 2021-01-19 06:22, Dan Ritter wrote:
> > 
> > My firewall (yes, it runs Debian) has an Intel 4x 1gig ethernet
> > card in it, as well as the 1 gig port on the motherboard. Each
> > is completely independent, so I have:
> > 
> > - one connection to the public Internet
> > - one connection to my switched network of wifi access points
> > - one connection to my general wired network switch
> > - one connection to my remote power switch
> > - and a free connection for the future.
> > 
> > Each of these has one or more different IP addresses, including
> > IPv6 on three ports, and packets are routed between them and
> > blocked by the firewall.
> 
> On 2021-01-19 08:40, Dan Ritter wrote:
> > [The remote power switch] can turn on and off a set of wall outlets,
> > to which other computers are attached. In other words, if the firewall
> > is running, I can power-cycle several other machines.
> 
> 
> I assume your Wi-Fi, LAN, and remote power switch interfaces are on
> different network segments (?).
> 
> 
> Do you have use-cases that require or benefit from this, or could you
> replace the 4-port NIC with a 1-port NIC connected to a switch connected to
> all of the inside devices (AP's, clients, servers, power gateway, etc.)?

The remote power switch doesn't have to be directly attached;
it could be attached to the switch that the general wired
network uses. However, it needs to be fully functional with just
the firewall being alive -- the idea is that if I can get into
my firewall, I can deal with a hung server.

The APs are deliberately separated from the wired network:
nothing on an AP is trusted more than the general Internet,
except that they get to see DHCP, DNS, NTP and a printer.

All the wired devices trust each other a bit more; there are
some NFS mounts that allow an entire subnet to read from them,
for example.

So I could drop down to a 2-port NIC, using 3 total and not
having any spares, but I already have this setup, and it's been
running nicely since 2014. I spent about $250 on it, including
some parts I had lying around, and with luck it will last until
something better than gigabit fiber comes to my neighborhood
with nothing worse than a power-supply replacement for $40 or
so. The best part is that it runs straight Debian, AMD64, so
unlike all the SOHO routers, it stays up to date.

-dsr-

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#230867

On 2021-01-19 14:35, Dan Ritter wrote:
> David Christensen wrote:
>> On 2021-01-19 06:22, Dan Ritter wrote:
>>>
>>> My firewall (yes, it runs Debian) has an Intel 4x 1gig ethernet
>>> card in it, as well as the 1 gig port on the motherboard. Each
>>> is completely independent, so I have:
>>>
>>> - one connection to the public Internet
>>> - one connection to my switched network of wifi access points
>>> - one connection to my general wired network switch
>>> - one connection to my remote power switch
>>> - and a free connection for the future.
>>>
>>> Each of these has one or more different IP addresses, including
>>> IPv6 on three ports, and packets are routed between them and
>>> blocked by the firewall.
>>
>> On 2021-01-19 08:40, Dan Ritter wrote:
>>> [The remote power switch] can turn on and off a set of wall outlets,
>>> to which other computers are attached. In other words, if the firewall
>>> is running, I can power-cycle several other machines.
>>
>>
>> I assume your Wi-Fi, LAN, and remote power switch interfaces are on
>> different network segments (?).
>>
>>
>> Do you have use-cases that require or benefit from this, or could you
>> replace the 4-port NIC with a 1-port NIC connected to a switch connected to
>> all of the inside devices (AP's, clients, servers, power gateway, etc.)?
> 
> The remote power switch doesn't have to be directly attached;
> it could be attached to the switch that the general wired
> network uses. However, it needs to be fully functional with just
> the firewall being alive -- the idea is that if I can get into
> my firewall, I can deal with a hung server.
> 
> The APs are deliberately separated from the wired network:
> nothing on an AP is trusted more than the general Internet,
> except that they get to see DHCP, DNS, NTP and a printer.
> 
> All the wired devices trust each other a bit more; there are
> some NFS mounts that allow an entire subnet to read from them,
> for example.
> 
> So I could drop down to a 2-port NIC, using 3 total and not
> having any spares, but I already have this setup, and it's been
> running nicely since 2014. I spent about $250 on it, including
> some parts I had lying around, and with luck it will last until
> something better than gigabit fiber comes to my neighborhood
> with nothing worse than a power-supply replacement for $40 or
> so. The best part is that it runs straight Debian, AMD64, so
> unlike all the SOHO routers, it stays up to date.


I have a SOHO network.  Our Wi-Fi devices need access to LAN hosts and 
vice-versa.  I set up WPA2 and MAC filtering on the Wi-Fi, and put the 
Wi-Fi devices on the LAN.


Server-grade multi-port NIC's are expensive parts.  When I ran PC 
firewalls, I used desktop NIC's to supplement the motherboard port. 
Inexpensive Fast Ethernet (100 Mbps) cards and switches were, and still 
are, sufficient for the downstream side of my Internet connection.


David

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#230869

David Christensen wrote: 
> On 2021-01-19 14:35, Dan Ritter wrote:
> > So I could drop down to a 2-port NIC, using 3 total and not
> > having any spares, but I already have this setup, and it's been
> > running nicely since 2014. I spent about $250 on it, including
> > some parts I had lying around, and with luck it will last until
> > something better than gigabit fiber comes to my neighborhood
> > with nothing worse than a power-supply replacement for $40 or
> > so. The best part is that it runs straight Debian, AMD64, so
> > unlike all the SOHO routers, it stays up to date.
> 
> 
> I have a SOHO network.  Our Wi-Fi devices need access to LAN hosts and
> vice-versa.  I set up WPA2 and MAC filtering on the Wi-Fi, and put the Wi-Fi
> devices on the LAN.
> 
> 
> Server-grade multi-port NIC's are expensive parts.  When I ran PC firewalls,
> I used desktop NIC's to supplement the motherboard port. Inexpensive Fast
> Ethernet (100 Mbps) cards and switches were, and still are, sufficient for
> the downstream side of my Internet connection.

Well, they were expensive when new. A used quad-gig-e PCIe card
is now $20-35 on Ebay, and I see someone with a supply of
Chelsio quad cards with 2 10g nics and 2 1g nics for $50 each.

The things that flow downstream can be recycled for the home
market...

-dsr-

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#230844

On Tue, 2021-01-19 at 12:47 +0000, mick crane wrote:
> hello,
> I see that you can get a single network card with 2, 3, 4
> connections.
> Can you happily make each one on a separate private address block ?
> 10.0.0.0, 172.16.0.0, 192.168.0.0
> 
> mick
> 
Yes,
but depending on your network topology you might screw up things.
Make sure that each virtual nic links to a VLAN with the correct 
block.

-H

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#230846

Hi Mick,

On Tue, Jan 19, 2021 at 12:47:34PM +0000, mick crane wrote:
> I see that you can get a single network card with 2, 3, 4 connections.
> Can you happily make each one on a separate private address block ?
> 10.0.0.0, 172.16.0.0, 192.168.0.0

There is no strong connection between the concept of a physical port
and the logical addresses you put on an interface associated with.
You can create a virtual network interface in a machine with no
network hardware at all, and put a billion different IPv6 networks
on it if you like!

Cheers,
Andy

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#230863

On 2021-01-19 04:47, mick crane wrote:
> hello,
> I see that you can get a single network card with 2, 3, 4 connections.
> Can you happily make each one on a separate private address block ?
> 10.0.0.0, 172.16.0.0, 192.168.0.0

Yes, and more:

https://en.wikipedia.org/wiki/Link_aggregation


One feature of link aggregation is increased throughput -- two physical 
connections can work together as one logical connection that is twice as 
fast.


But the killer feature is redundancy -- if every device is connected to 
two different switches, you can do maintenance on one switch and the 
network will remain up via the other switch.


David

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#230864

David Christensen <dpchrist@holgerdanske.com> wrote:

> One feature of link aggregation is increased throughput -- two physical 
> connections can work together as one logical connection that is twice as 
> fast.

With the caveat that this does not increase the throughput of a single
flow. 

> But the killer feature is redundancy -- if every device is connected
> to two different switches, you can do maintenance on one switch and
> the network will remain up via the other switch.

Noteworthy here: If you want to do 802.3ad (aka LACP) the switches need
to be either stacked, use VSS/IRF or be compatible with MLAG/MC-LAG.

If you don't have such switches, you are limited to active-backup or
TLB/ALB-mode of the bonding code.

S°

-- 
Sigmentation fault. Core dumped.

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