IPv6 for self hosters
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No need to put some AI slop in here.
None of this is AI generated
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So what is IPv6 and why should you care? IPv6 is intended to be the successor of IPv4 and most people know it for the very large address space. However, it has many other benefits as well and is worth learning for self hosting purposes.
IPv6 features
Huge address space
With IPv6, you no long need to be concerned with the limited address space of IPv4. In IPv6 land devices can have many different IPv6 addresses. You can have a different IPv6 address for each service and with the privacy extensions you can have a different IPv6 addresses for each outgoing connection on your computer.
Simplified subnetting
In IPv6 land everything is done via prefixes. An IPv6 prefix is simply the first half of the address which is used in routing to send traffic where it needs to go. A prefix is typically assigned to a vlan and the prefix is then delegated to all devices in that vlan. Because each device can have multiple addresses you can have each device get a public address and also a private address. A prefix is a /64 and if you want multiple prefixes you can get something like a /56, /48 or /32. (CIDR notation) To get a prefix from an ISP you use something called DHCPv6-PD. This is a lot like normal DHCP but it requests one or more prefixes from your ISP.
SLAAC (Stateless address autoconfig)
With SLAAC, devices pick an address and then verify it isn't duplicated. From there a router will send out a RA (router advertisement) which tells the device what prefix to use. The device then drops the link local prefix and replaces it will a public prefix. The major benefit of this is that you no longer need to keep track of DHCP leases. SLAAC allows networks to self assemble without much setup.
IPv6 security and privacy
IPv6 still needs a firewall to be secure. You should not expose things to the internet without properly securing them and anything that is publicly accessible can be compromised. IPv6 also can create major privacy issues since each device has a public IP. SLAAC and the privacy extensions help a lot as they randomize IPs which makes tracking harder. However, devices still share a public prefix so there still could be privacy issues.
NAT64 to eliminate IPv4
One of the technologies to help eliminate the need for IPv4 is NAT64. NAT64 works by mapping IPv4 address to IPv6 ones by setting a prefix that fills in the upper space of the address. To delicate this prefix to devices you can either use Pref64 or DHCPv6 opt 108. On the device applications see a working IPv4 address since the operating system translates IPv4 to IPv6 before it goes onto the network. You can absolutely keep using IPv4 and NAT64 is only for those who want to be IPv6 exclusive networks.
I’ve considered using v6 as I host a lot of services from my homelab and it would be great if each had its own address. The question I have is, is v6 prevalent enough that all the clients out there are ready to go and I can just switch my lab servers to v6 and swap my A records with AAAA records, or will I still need to serve up v4 (and therefore, may as well just stick with the topology, reverse proxies, etc. I’ve already got.)
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I’ve considered using v6 as I host a lot of services from my homelab and it would be great if each had its own address. The question I have is, is v6 prevalent enough that all the clients out there are ready to go and I can just switch my lab servers to v6 and swap my A records with AAAA records, or will I still need to serve up v4 (and therefore, may as well just stick with the topology, reverse proxies, etc. I’ve already got.)
You just need a network that is capable of IPv6
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So what is IPv6 and why should you care? IPv6 is intended to be the successor of IPv4 and most people know it for the very large address space. However, it has many other benefits as well and is worth learning for self hosting purposes.
IPv6 features
Huge address space
With IPv6, you no long need to be concerned with the limited address space of IPv4. In IPv6 land devices can have many different IPv6 addresses. You can have a different IPv6 address for each service and with the privacy extensions you can have a different IPv6 addresses for each outgoing connection on your computer.
Simplified subnetting
In IPv6 land everything is done via prefixes. An IPv6 prefix is simply the first half of the address which is used in routing to send traffic where it needs to go. A prefix is typically assigned to a vlan and the prefix is then delegated to all devices in that vlan. Because each device can have multiple addresses you can have each device get a public address and also a private address. A prefix is a /64 and if you want multiple prefixes you can get something like a /56, /48 or /32. (CIDR notation) To get a prefix from an ISP you use something called DHCPv6-PD. This is a lot like normal DHCP but it requests one or more prefixes from your ISP.
SLAAC (Stateless address autoconfig)
With SLAAC, devices pick an address and then verify it isn't duplicated. From there a router will send out a RA (router advertisement) which tells the device what prefix to use. The device then drops the link local prefix and replaces it will a public prefix. The major benefit of this is that you no longer need to keep track of DHCP leases. SLAAC allows networks to self assemble without much setup.
IPv6 security and privacy
IPv6 still needs a firewall to be secure. You should not expose things to the internet without properly securing them and anything that is publicly accessible can be compromised. IPv6 also can create major privacy issues since each device has a public IP. SLAAC and the privacy extensions help a lot as they randomize IPs which makes tracking harder. However, devices still share a public prefix so there still could be privacy issues.
NAT64 to eliminate IPv4
One of the technologies to help eliminate the need for IPv4 is NAT64. NAT64 works by mapping IPv4 address to IPv6 ones by setting a prefix that fills in the upper space of the address. To delicate this prefix to devices you can either use Pref64 or DHCPv6 opt 108. On the device applications see a working IPv4 address since the operating system translates IPv4 to IPv6 before it goes onto the network. You can absolutely keep using IPv4 and NAT64 is only for those who want to be IPv6 exclusive networks.
I think I'll die using IPv4 behind NAT along with VPN.
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So what is IPv6 and why should you care? IPv6 is intended to be the successor of IPv4 and most people know it for the very large address space. However, it has many other benefits as well and is worth learning for self hosting purposes.
IPv6 features
Huge address space
With IPv6, you no long need to be concerned with the limited address space of IPv4. In IPv6 land devices can have many different IPv6 addresses. You can have a different IPv6 address for each service and with the privacy extensions you can have a different IPv6 addresses for each outgoing connection on your computer.
Simplified subnetting
In IPv6 land everything is done via prefixes. An IPv6 prefix is simply the first half of the address which is used in routing to send traffic where it needs to go. A prefix is typically assigned to a vlan and the prefix is then delegated to all devices in that vlan. Because each device can have multiple addresses you can have each device get a public address and also a private address. A prefix is a /64 and if you want multiple prefixes you can get something like a /56, /48 or /32. (CIDR notation) To get a prefix from an ISP you use something called DHCPv6-PD. This is a lot like normal DHCP but it requests one or more prefixes from your ISP.
SLAAC (Stateless address autoconfig)
With SLAAC, devices pick an address and then verify it isn't duplicated. From there a router will send out a RA (router advertisement) which tells the device what prefix to use. The device then drops the link local prefix and replaces it will a public prefix. The major benefit of this is that you no longer need to keep track of DHCP leases. SLAAC allows networks to self assemble without much setup.
IPv6 security and privacy
IPv6 still needs a firewall to be secure. You should not expose things to the internet without properly securing them and anything that is publicly accessible can be compromised. IPv6 also can create major privacy issues since each device has a public IP. SLAAC and the privacy extensions help a lot as they randomize IPs which makes tracking harder. However, devices still share a public prefix so there still could be privacy issues.
NAT64 to eliminate IPv4
One of the technologies to help eliminate the need for IPv4 is NAT64. NAT64 works by mapping IPv4 address to IPv6 ones by setting a prefix that fills in the upper space of the address. To delicate this prefix to devices you can either use Pref64 or DHCPv6 opt 108. On the device applications see a working IPv4 address since the operating system translates IPv4 to IPv6 before it goes onto the network. You can absolutely keep using IPv4 and NAT64 is only for those who want to be IPv6 exclusive networks.
I was excited for IPv6 in the 90s.
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I was excited for IPv6 in the 90s.
It took a lot of time to mature
We made progress after the engineers excepted NAT and firewalls
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I was excited for IPv6 in the 90s.
I took the networking TCP/IP fundamentals class for my first MCSE in 99, and the instructor wouldn’t shut up about how IPv4 would be replaced within 5 years.
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Going to other planets would require a total re-architecting of our communications infrastructure anyway. There's such distance too it's not really viable to have a shared internet. Even Mars would have up to 22 minute latency at peak. So I don't think it makes sense to plan our current internet around potential future space colonization.
Even so, IPv6 is truly massive. We could give a /64 to every square centimeter of the Earth's surface and still have IPs to spare. Frankly, I think the protocol itself will be obsolete before we run out.
You thought so, but in year 2525 they will still be complaining about TCP congestion mechanisms
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You probably need private addressing
SLAAC shouldn't be used with static IPs
The "correct" way to handle "static" addresses with dynamic prefix is using tokenized network interfaces (which is pretty much just the lower 64 bits of the IPv6 address). That will then be used for SLAAC in addition to the randomly generated address. The support for dynamic prefixes in firewalls on Linux and Mikrotik is however still pretty dire (obviously, as it's not an enterprise feature). No clue about BSDs/pfSense
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So what is IPv6 and why should you care? IPv6 is intended to be the successor of IPv4 and most people know it for the very large address space. However, it has many other benefits as well and is worth learning for self hosting purposes.
IPv6 features
Huge address space
With IPv6, you no long need to be concerned with the limited address space of IPv4. In IPv6 land devices can have many different IPv6 addresses. You can have a different IPv6 address for each service and with the privacy extensions you can have a different IPv6 addresses for each outgoing connection on your computer.
Simplified subnetting
In IPv6 land everything is done via prefixes. An IPv6 prefix is simply the first half of the address which is used in routing to send traffic where it needs to go. A prefix is typically assigned to a vlan and the prefix is then delegated to all devices in that vlan. Because each device can have multiple addresses you can have each device get a public address and also a private address. A prefix is a /64 and if you want multiple prefixes you can get something like a /56, /48 or /32. (CIDR notation) To get a prefix from an ISP you use something called DHCPv6-PD. This is a lot like normal DHCP but it requests one or more prefixes from your ISP.
SLAAC (Stateless address autoconfig)
With SLAAC, devices pick an address and then verify it isn't duplicated. From there a router will send out a RA (router advertisement) which tells the device what prefix to use. The device then drops the link local prefix and replaces it will a public prefix. The major benefit of this is that you no longer need to keep track of DHCP leases. SLAAC allows networks to self assemble without much setup.
IPv6 security and privacy
IPv6 still needs a firewall to be secure. You should not expose things to the internet without properly securing them and anything that is publicly accessible can be compromised. IPv6 also can create major privacy issues since each device has a public IP. SLAAC and the privacy extensions help a lot as they randomize IPs which makes tracking harder. However, devices still share a public prefix so there still could be privacy issues.
NAT64 to eliminate IPv4
One of the technologies to help eliminate the need for IPv4 is NAT64. NAT64 works by mapping IPv4 address to IPv6 ones by setting a prefix that fills in the upper space of the address. To delicate this prefix to devices you can either use Pref64 or DHCPv6 opt 108. On the device applications see a working IPv4 address since the operating system translates IPv4 to IPv6 before it goes onto the network. You can absolutely keep using IPv4 and NAT64 is only for those who want to be IPv6 exclusive networks.
All of this is great but the human brain can only accurately remember a sequence of 8 digit numbers so I think that’s why IPv4 is gonna stick around for a bit. I’ve memorized too many CIDR ranges 🫠
