4 ms·

The internal address is optional, it's only useful if you want to have a known address if your uplink is down so you can do maintainance. You only need two add

The internal address is optional, it's only useful if you want to have a known address if your uplink is down so you can do maintainance. You only need two addresses: - a global address - a link-local address

nottorp 4y ago
Not clear. How do i reach a device in my local network? Via the optional internal address if my uplink is down and via my link-local address if my uplink is up? Is the link-local address any good if i'm on wifi but want to ssh into a wired host in my home? Are you getting my point yet? Edit: actually I won't wait. The point is it's needlessly overcomplicated. It was done by a commitee that didn't even consider people could try to set up their home network. It's good enough for the enterprise (except cloud sellers it seems) and the plebs should just buy a router. They also didn't consider someone would try to use the command line, since those addresses are not typable.
- yesco 4y ago
  > Is the link-local address any good if i'm on wifi but want to ssh into a wired host in my home? Lets breath and think about this for a second, you want to know how to reach a device on your local network, your host has a "link-local" address. Could there be a connection here? The answer is yes because it's in the name, it's literally in the name, why are you confused? What is over complicated about this? Back when I was in college I did IPv6 compliance testing as a part time job. Me and random other freshman computer science + IT students were able to pick this up after a day or two of training (aka reading RFCs) with next to zero network experience. I really can't help but see your complaints about complexity as nothing but the whining of a child. (we also exclusively used the commandline)
  - nottorp 4y ago
    > your host has a "link-local" address. Could there be a connection here? Maybe. Or maybe not. It could apply only to hosts connected via the same switch? Or same AP? That's how i read link-local. It's obvious to you because you already know. > see your complaints about complexity as nothing but the whining of a child So point me to an overview of ipv6, enough to manually configure a small network, that is clear and complete. Not the RFCs please, I don't want to learn to configure an enterprise (or university) network. Last time I searched for one there wasn't one.
    - pantalaimon 4y ago
      Yes link-local is only local to the link (same broadcast domain). But most home networks are bridged on layer 2 anyway. IPv6 allows for a design where you don't have everything on the same broadcast domain but actually use subnets for e.g. the WiFi network. But since you still want to retain IPv4 compatibility, this is usually not an option in home networks. > So point me to an overview of ipv6, enough to manually configure a small network Just enable router advertisements on your router (likely already the case) to announce a /64 prefix that was derived from the prefix you got from your ISP. You also want to enable RDNSS so DNS server information is included with the router advertisement. (also usually the default) Then enable SLAAC on your hosts (already the default) to automatically select an address based on the prefix from the router advertisement. A /64 is big enough that the router doesn't have to individually assign addresses. Hosts can just pick one and if they are polite, ask if it's already used by someone else (duplicate address detection). Presto! You now have IPv6 connectivity.
      - nottorp 4y ago
        > Just enable router advertisements on your router Thats not “manually”. Thats clicking in the routers UI. My idea of manually is roll your own Linux. Worked just fine for ipv4, looks like a full time job for 6.
        pantalaimon 4y ago
        Then install radvd to enable router advertisements.
- pantalaimon 4y ago
  I think you are a bit confused. A global address is an address that is routable over the internet. You can reach it from anywhere as long as your firewall permits so. A link-local address is never routed. It is only valid on a single network segment. You can use it if your uplink is down and you don't have multiple networks at home. It is usually derived from the MAC address of your NIC. There are some special link-local multicast groups, ff02::1 is the 'all nodes' address. If you send something there it will be received by all hosts on the link. ff02::2 is 'all routers' - this will be received by all routers on the link. There are more [0]. If you have multiple internal networks and want to reach hosts without an uplink, you can use the unique local address range fc00::/7 This functions just like 10.0.0.0/8 on IPv4 and is only routed within your site. [0] https://www.iana.org/assignments/ipv6-multicast-addresses/ipv6-multicast-addresses.xhtml#link-local https://www.iana.org/assignments/ipv6-multicast-addresses/ip...

nottorp 4y ago

Not clear. How do i reach a device in my local network? Via the optional internal address if my uplink is down and via my link-local address if my uplink is up? Is the link-local address any good if i'm on wifi but want to ssh into a wired host in my home? Are you getting my point yet? Edit: actually I won't wait. The point is it's needlessly overcomplicated. It was done by a commitee that didn't even consider people could try to set up their home network. It's good enough for the enterprise (except cloud sellers it seems) and the plebs should just buy a router. They also didn't consider someone would try to use the command line, since those addresses are not typable.

yesco 4y ago
> Is the link-local address any good if i'm on wifi but want to ssh into a wired host in my home? Lets breath and think about this for a second, you want to know how to reach a device on your local network, your host has a "link-local" address. Could there be a connection here? The answer is yes because it's in the name, it's literally in the name, why are you confused? What is over complicated about this? Back when I was in college I did IPv6 compliance testing as a part time job. Me and random other freshman computer science + IT students were able to pick this up after a day or two of training (aka reading RFCs) with next to zero network experience. I really can't help but see your complaints about complexity as nothing but the whining of a child. (we also exclusively used the commandline)
- nottorp 4y ago
  > your host has a "link-local" address. Could there be a connection here? Maybe. Or maybe not. It could apply only to hosts connected via the same switch? Or same AP? That's how i read link-local. It's obvious to you because you already know. > see your complaints about complexity as nothing but the whining of a child So point me to an overview of ipv6, enough to manually configure a small network, that is clear and complete. Not the RFCs please, I don't want to learn to configure an enterprise (or university) network. Last time I searched for one there wasn't one.
  - pantalaimon 4y ago
    Yes link-local is only local to the link (same broadcast domain). But most home networks are bridged on layer 2 anyway. IPv6 allows for a design where you don't have everything on the same broadcast domain but actually use subnets for e.g. the WiFi network. But since you still want to retain IPv4 compatibility, this is usually not an option in home networks. > So point me to an overview of ipv6, enough to manually configure a small network Just enable router advertisements on your router (likely already the case) to announce a /64 prefix that was derived from the prefix you got from your ISP. You also want to enable RDNSS so DNS server information is included with the router advertisement. (also usually the default) Then enable SLAAC on your hosts (already the default) to automatically select an address based on the prefix from the router advertisement. A /64 is big enough that the router doesn't have to individually assign addresses. Hosts can just pick one and if they are polite, ask if it's already used by someone else (duplicate address detection). Presto! You now have IPv6 connectivity.
    - nottorp 4y ago
      > Just enable router advertisements on your router Thats not “manually”. Thats clicking in the routers UI. My idea of manually is roll your own Linux. Worked just fine for ipv4, looks like a full time job for 6.
      - pantalaimon 4y ago
        Then install radvd to enable router advertisements.
pantalaimon 4y ago
I think you are a bit confused. A global address is an address that is routable over the internet. You can reach it from anywhere as long as your firewall permits so. A link-local address is never routed. It is only valid on a single network segment. You can use it if your uplink is down and you don't have multiple networks at home. It is usually derived from the MAC address of your NIC. There are some special link-local multicast groups, ff02::1 is the 'all nodes' address. If you send something there it will be received by all hosts on the link. ff02::2 is 'all routers' - this will be received by all routers on the link. There are more [0]. If you have multiple internal networks and want to reach hosts without an uplink, you can use the unique local address range fc00::/7 This functions just like 10.0.0.0/8 on IPv4 and is only routed within your site. [0] https://www.iana.org/assignments/ipv6-multicast-addresses/ipv6-multicast-addresses.xhtml#link-local https://www.iana.org/assignments/ipv6-multicast-addresses/ip...