Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Tell HN: Hacker News now supports IPv6

news.ycombinator.com

Post reply on HN
Print view View original

151–160 of 396 posts

Re: Tell HN: Hacker News now supports IPv6

#151

Post by ale42 »

londons_explore wrote: post #76
lmm wrote: post #73

Earlier quoted context omitted.

CIDR and the resulting address space fragmentation was the problem that IPv6 was originally meant to solve; allowing splitting into random-sized subnets makes routing more complex and worse. And if you made the routable part of an IPv6 address longer than 64 bits then that makes the routing much more compute-intensive. 64 bits in the local part of the address is sort of overkill, but a 128 bit address isn't really an…

You can still use a shorter hash of the Mac address. Collisions are very unlikely, and a quick ARP packet should detect them if they do happen.

It would rather be an ICMPv6 neighbor discovery packet or something like that, IPv6 doesn't use ARP.

Re: Tell HN: Hacker News now supports IPv6

#152

Post by greyface- »

mike_d wrote: post #140
greyface- wrote: post #40

Earlier quoted context omitted.

That sure sounds like a lot. But "billions" is less than a /64. Try "sextillions" (/56) or "septillions" (/48). Of course, when the denominator is "undecillions", it becomes clear that this is actually a non-issue.

ARIN recently handed out a /16 allocation to Capital One. That is one 65,025th of all of IPv6. A reasonable sized /32 allocation would have allowed for giving every ATM they operate worldwide its own globally routable /48.

Too bad ARIN tickets aren't public - I would love to read the one in which that was justified. Reading NRPM 6.5.2.1, it seems that they must have submitted documentation claiming at least 2^28 distinct serving sites in order to qualify for an assignment that large.

Re: Tell HN: Hacker News now supports IPv6

#153

Post by Denvercoder9 »

mike_d wrote: post #134
Plasmoid wrote: post #107

Earlier quoted context omitted.

Another person who does not understand IPv4. IPv4 isn't a text based protocol where IP addresses are parsed like DNS. It's a binary protocol where addresses are recorded in binary and adding more address space WOULD BE A BREAKING CHANGE.

Not at all. We could have taken one of the unassigned /8's at the time and allocated it to v6 transitional addressing (the failure to address 4->6 reachability is IMO why v6 failed). For the sake of this example lets use 53.0.0.0/8. All new addresses start with 00110101 followed by the first three bytes of the new v6 prefix. The prefix acts as a flag that indicates it is a new address and routers read an additional 5…

> They put letters in the middle of numbers

If you prefer, you could write an IPv6 address in dotted-decimal notation just like an IPv4 address, or an IPv4 in hexadecimal notation like an IPv6 address. It's just 128 (IPv6) or 32 (IPv4) bits of data after all, the representation is completely independent of the protocol.

For example, you can also reach HN through its IPv4 address by writing http://3520653007/ or http://0xD1D8E6CF/.

Re: Tell HN: Hacker News now supports IPv6

#154

Post by ta1243 »

mike_d wrote: post #140
greyface- wrote: post #40

Earlier quoted context omitted.

That sure sounds like a lot. But "billions" is less than a /64. Try "sextillions" (/56) or "septillions" (/48). Of course, when the denominator is "undecillions", it becomes clear that this is actually a non-issue.

ARIN recently handed out a /16 allocation to Capital One. That is one 65,025th of all of IPv6. A reasonable sized /32 allocation would have allowed for giving every ATM they operate worldwide its own globally routable /48.

I find the insistence of using /64s everywhere for networks frustrating. Any network larger than a /112 seems crazy, that's already 65k IPs per subnet. A /104 for every normal end user (256 subnets per user), or a /80 for massive companies like Capital One (4 billion subnets) should be more than enough.

Re: Tell HN: Hacker News now supports IPv6

#155

Post by ale42 »

schroeding wrote: post #110
Plasmoid wrote: post #107

Earlier quoted context omitted.

Another person who does not understand IPv4. IPv4 isn't a text based protocol where IP addresses are parsed like DNS. It's a binary protocol where addresses are recorded in binary and adding more address space WOULD BE A BREAKING CHANGE.

For a practical demonstration: That's the reason decimal IPs work, too - i.e. http://3520653007/ is the same as http://209.216.230.207/ (and both will go to HN) - it's all just nice formating for our human brains. Nothing would stop us from formatting IPv6 the IPv4 way except the monstrous length of the resulting address.

You can even make it funnier by having it look like a floating point number: http://209.14214863/

Or a strange number with two decimal parts: http://209.216.59087/

Re: Tell HN: Hacker News now supports IPv6

#156

Post by btgeekboy »

SamuelAdams wrote: post #4
tlivolsi wrote: post #2

[flagged]

Can you explain this more? Why are you so tied to ipv4? I recently enabled IPv6 on my home network, and roughly 30-40% of all internet traffic goes through IPv6. Things are noticeably faster, especially connection times to online games on Xbox Live. My only complaint is that my ISP keeps changing the prefix every quarter or so, so my static addresses need to be updated in the firewall and other places. I am looking i…

I turned it off on my home network. I have a multi-wan setup (fiber + 5g). The 5g provider supports v6, but only delegates a /64. The fiber provider will delegate me a /56, which is plenty for both my home and guest networks. Failover for v4 works great, as everything's behind NAT so the route just changes when my firewall detects an issue, but clients accessing v6 resources have a hard time, as you're waiting on each device to figure out that the old route is dead. So that's problem number one.

Problem number two is that the fiber provider doesn't support native v6; it's actually a 6rd tunnel. Latency isn't great compared to v4.

I need to go figure out the ULA situation and do NPTv6. But last I checked, my firewall wasn't able to do NPTv6 with delegated ranges. That may have changed, but I've not found any substantial reason to actually put in the effort to figure out it when my v4 network works fine.

Re: Tell HN: Hacker News now supports IPv6

#157

Post by ta1243 »

pilif wrote: post #49
p-e-w wrote: post #31

Earlier quoted context omitted.

The last time I looked into this (which was a few years ago), ISPs were allocating blocks containing billions of IPv6 addresses to anyone who paid a nominal sum. So that vast address space might not last as long as it would seem...

One of the features of IPv6 is address autoconfiguration, obviating the need for a central authority like DHCP on v4. However, that only works with a /64 prefix and given that larger sites might want to have multiple subnets, that’s why most assignments are /56 or /48. But still. If all assignments were /48s, that would still leave room for 281 trillion networks which even I believe is enough for the foreseeable futu…

But they aren't all /48s. Upthread there's a post about /16s already being allocated.

Re: Tell HN: Hacker News now supports IPv6

#158

Post by ale42 »

mike_d wrote: post #136
Uehreka wrote: post #129

Earlier quoted context omitted.

Huh? IPv6 does have backwards-compatible-ish notation for writing IPv4 addresses. To take your example: 1.2.3.4 would be ::ffff:1.2.3.4, the 96-bit prefix indicated by ::ffff: is where all of the IPv4 addresses live in the larger IPv6 space. If your issue is with the use of colons at all, they were a deliberate choice so that computers doing string processing could never confuse the two types of addresses.

> they were a deliberate choice so that computers doing string processing could never confuse the two types of addresses. Wait until you try to write an IPv6 address with a port number in standard notation.

Usually IPv6 addresses are enclosed in square brackets when a port number is involved. But it's true that in many configuration files IPv6s are a nightmare to put in, especially because you never remember what syntax you have to use: sometimes you even have to duplicate semicolons (that's what Exim does...). But I think this is rather a convention problem for the config files, rather a problem of IPv6 addresses themselves.

Re: Tell HN: Hacker News now supports IPv6

#159

Post by ta1243 »

londons_explore wrote: post #76
lmm wrote: post #73

Earlier quoted context omitted.

CIDR and the resulting address space fragmentation was the problem that IPv6 was originally meant to solve; allowing splitting into random-sized subnets makes routing more complex and worse. And if you made the routable part of an IPv6 address longer than 64 bits then that makes the routing much more compute-intensive. 64 bits in the local part of the address is sort of overkill, but a 128 bit address isn't really an…

You can still use a shorter hash of the Mac address. Collisions are very unlikely, and a quick ARP packet should detect them if they do happen.

Collisions are just as likely with the 48 bits as they are with the last 24 bits, as some OUI vendors reuse mac addresses.

Using a mac address in the IP is terrible anyway from a privacy point of view, use a random IP in the subnet, send out a check to see if it's already used, if it is choose a new one. That check is already a feature of ipv6.

Re: Tell HN: Hacker News now supports IPv6

#160

Post by ale42 »

bqmjjx0kac wrote: post #55
rumdz wrote: post #36

Does ipv6 result in higher latencies? I could see larger addresses increasing latency, but then again I could also see a more efficient protocol resulting in lower net latency. I should probably read a book describing the differences.

Verizon Fios recently rolled out IPv6 last year and I swear IPv6 traffic is deprioritized. Sometimes it just cuts out entirely.

Sounds like a technical problem. I don't see any reason they should de-prioritize IPv6 traffic...
Post reply on HN