Re: IPv6 Performance (was Re: IPv4 Pricing)

[Tim Burke via NANOG <nanog () lists nanog org>]

Even better, there are providers (major national ones, even!) that only provide IPv6 to DHCP customers, if you pay 
extra for static IPv4, there *is* no IPv6.

Then again, that same provider only has IPv6 on ~5% of their network: 
https://stats.labs.apnic.net/ipv6/AS5650?c=US&p=1&v=1&w=30&x=1

On Dec 1, 2025, at 4:47 PM, Chris Woodfield via NANOG <nanog () lists nanog org> wrote:

I’ll chime in my personal beef with IPv6, or at least, my home ISP’s implementation…

Unless I want to pay $$$ for a “business-class” service for my home, my IP allocations, both IPv4 and V6, are not 
statically assigned. While they don’t change often, they have in the past.

Now, if I want to assign static addresses for devices within my home network, I don’t have a problem with v4 - 
everything’s RFC1918, so if the public IP changes, NBD, and I can even do it with DHCP client IDs. However, if my IPv6 
PD changes and my home devices all have GUAs assigned via SLAAC, then… guess what - every IPv6 device address in my 
network just changed. Oops.

Practically, I’ve worked around this by manually assigning LUAs to the devices that need static v6 addresses, like my 
SAN and the machines that do NFS mounts from it. But 1. that’s more than annoyingly clunky - hardly the improved 
experience that IPv6 promised - and 2. weren’t we trying to get away from LUAs in the first place?

-Chris

On Dec 1, 2025, at 13:44, Bryan Fields via NANOG <nanog () lists nanog org> wrote:

On 12/1/25 14:22, Jared Mauch via NANOG wrote:

I find myself having to tether off their networks when I’m on IPv4 only
networks to access things like my hypervisors and other assets that are
IPv6-only because they have superior networking these days.

While I'll agree v6 is easy and should be deployed I have to take issue with the current as-built being superior.

At least once or twice a month I'm downloading something and will find the IPv4 to transfer significantly faster.  Case 
in point, I downloaded the proxmox iso yesterday to a colo server with 50g uplinks.  It loafed at 2.4 mbytes/s using 
default wget, which of course preferred ipv6.  Adding -4 to wget made that shoot up to 80 mbytes/s.

This is ipv6 behavior I've seen time and time again.  I'm unsure where problems like these lie in the network, other 
than it's not mine or my peers. I've seen the same issues with v6 paths to the same server bounce around the west coast 
and back, whilst IPv4 is 6 hops and 12 ms away.

This is exactly the sort of thing that holds IPv6 back by giving it a bad name.
--
Bryan Fields

727-409-1194 - Voice
http://bryanfields.net
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