Re: How to use bridge-utils to enable connection sharing?
> Am 05.02.2023 um 18:30 schrieb Dan Ritter:
> > (...)
> > RJ45 is a physical connector with 8 pairs of twisted wires. The
> > twisted pairs carry the same signal but with the polarity
> > reversed, + on one is - on the other. Together with the
> > twisting, that makes the signal being carried resistant to
> > interference. Ethernet is a low level protocol often carried by
> > RJ45-connected twisted pair cables.
> >
> > Bridging extends a network segment. Routing makes decisions
> > about where IP packets should go.
> >
> > The router that connects to the internet for you is probably
> > doing several jobs:
> >
> > - it is bridging from a long-haul network like xDSL, DOCSIS
> > (cable modem), or fiber, to your local ethernet
> That is correct, DOCSIS in my case.
> >
> > - it is acquiring an IP address from the provider and using it
> > as your public address
> >
> > - it is probably using network address translation (NAT) to
> > allow multiple internal addresses to masquerade as the single
> > public address
> >
> > - it is probably providing those internal addresses via DHCP
> I can confirm all of the above. And i'd have to add, that matters got
> more complicated with dozens of VM's running on the host, and atm 5
> networks serving different purposes, which would really need some
> unwinding to happen for progress to be even possible. I am afraid,
> that i did create all this mess over time due to my understanding
> being so poor...
> >
> > It would be reasonably cheap to put an ethernet switch between
> > the router and your existing host and new backup host. In the
> > US, an 8 port ethernet switch is $28:
> > https://www.newegg.com/netgear-gs308-300pas-8-x-rj45/p/N82E16833222029?Item=N82E16833222029
> >
> > and you would need at least two more ethernet cables, which are
> > also cheap.
> >
> > $7.50 for preterminated 25 foot cable
> > https://www.newegg.com/yellow-belkin-25-ft-accessories-cable-management/p/N82E16812107315?Item=9SIB897JGS5925
> >
> > I presume that there are similar companies in Germany which will
> > sell you basically the same things.
> >
> > You unplug the host from the router, plug the router into the
> > switch, and the two hosts into the switch. No configuration
> > changes, most likely. Everything is likely to work.
> >
> > ---
> > If you insist on plugging your second host directly into your first,
> > you can do that instead:
> >
> > - configure an ethernet interface on both sides with an RFC1918
> > network address
> >
> > - plug them into each other
> >
> > - you can now ping each from the other
> >
> > - now you configure routing and NAT masquerading on your primary
> > host to hide the secondary host behind it
> >
> > I don't recommend this. Buy a switch and some cables.
I would second that recommendation. Get it all working and then play
with the network afterwards if you must.
> > -dsr-
> >
>
> I believe, this would work, because i had someone lend me a switch for
> some time and it just worked (somehow).
> For some reason, i am still interested to get bridge-utils to work,
> and i am taking your hint, to use static ip configuration as a
> starting point. The difficulty in that case: the backup-server does
> not have any OS at this point, which makes it necessary to switch
> keyboard and monitor several times in the process, and my handicap
> forces me to ask someone for physical help in order to do that.
> Very inconvenient to say the least. :-(
You don't say what you've done, but I presume you're following
https://wiki.debian.org/BridgeNetworkConnections
What steps have you taken?
Regarding your computer without an OS, can you not load a Live system
from CD or DVD or USB stick? None should require Internet access to
start up and be usable.
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