• 2 Posts
  • 41 Comments
Joined 2 years ago
Cake day: July 15th, 2023
  • Thomas@discuss.tchncs.detoSelfhosted@lemmy.world•Turn linux server into a router?English
    2·
    1 month ago

    I had a very similar problem as @Toralv@lemmy.world a few weeks ago. I repurposed a small, fanless x86 desktop computer as my new router. It has only one RJ45 port and due to its small size cannot be extended with a proper network card. As it has an unused USB3 port, I acquired a cheap Realtek-based USB3-to-RJ45 ‘adapter’ as the second network interface. It works without any further issues in Linux (Arch) and has no problems to handle Gbps traffic.

    For the router configuration, I am using ‘nftables’ instead of ‘iptables’, as the former is supposed the successor of the latter. I only used the new nftables configuration, but there are wrappers available so that one can continue to use iptables syntax if desired.

    For network configuration, I am using systemd’s networkd. Check systemd.network(5): Configuration option ‘IPMasquerade’ takes care of telling nftables/iptables to setup masquerading (rendering the iptables invocation @thebardingreen@lemmy.starlightkel.xyz exemplified unnecessary), options ‘IPv4Forwarding’ and ‘IPv6Forwarding’ renders manually changing ‘/proc/sys/net/ipv4/ip_forward’ unnecessary.

    systemd’s networkd has a built-in DHCP server; check option ‘DHCPServer’ and section ‘DHCPServer’ for that (same man page as above). This way you can skip installing/configuring a separate DHCP server, but systemd’s DHCP server has some limitations, such as only supporting DHCPv4 and lack of proper command line tools. For example, to retrieve the list of current leases, you would have to make a dbus call to networkd, e.g. via busctl or dbus-send.

    Bridges can also be configured with systemd’s networkd, making a separate bridge tool unnecessary. Rather straight-forward with three small configuration files, telling networkd that you want to have a bridge, its name (e.g. br0), its MAC address, which NICs will be part of the bridge, and the bridge’s configuration like a NIC itself (e.g. static IP address, that the networkd’s DHCP server shall listen here, …).

  • Thomas@discuss.tchncs.detoWorld News@lemmy.world•China's overqualified youth taking jobs as drivers, labourers and film extrasEnglish
    82·
    8 months ago

    From what I heard from a teacher who was on exchange to China is that traditional Chinese education values the memorization and ability to rephrase or reproduce previous scholars’ work, but neglects reflection and own ideas, especially if you are just a student. Western academic traditional to the contrast values the student’s ability to evaluate, compare, and reflect on previous work. Hypothetically, a report that would give you a pass with distinction at a Chinese university would make a plagiarism checker cry at a Western university and vice versa.

  • Thomas@discuss.tchncs.detoWorld News@lemmy.world•Sweden tells Germany: Reform your electricity market for power cable approvalEnglish
    21·
    9 months ago

    Many arguments call countries’ names, but actually prices are dictated by companies (directly or indirectly by their behavior) that want to make a profit. Sweden’s electricity prices, as a rule of thumb, are always lower than prices in Germany, so from an economic p.o.v. it makes sense to buy as much electricity in Sweden as can be transported south. Of course, that drives prices up in Sweden to historic level (but still cheaper than in Germany). Why are prices so high in Germany? Several reasons have been discussed here, but one I would like to highlight is that operators of gas and coal power plants, which are meant as reserves in cases of high demand and low supply, do not produce sufficiently much electricity: they simply earn more by selling little electricity at high prices than by selling more electricity at lower prices. The politicians’ fault is that they have created a mostly unregulated market where under the right conditions some actors can make huge profits at the cost of everyone else. This is why more nuclear power plants won’t help: even their operators will have to pay back the huge debts left from construction and thus also will try to maximize profits from high prices via low supply.