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What is the origin of the private network address 192.168.*.*? (2009)

Original Article

Hacker News Discussion

This Hacker News discussion primarily revolves around the historical reasons and implications of using private IP address ranges, specifically 192.168.0.0/16, 172.16.0.0/12, and 10.0.0.0/8.

The Origin Story: Anecdotes and Authoritative Accounts

A significant portion of the discussion attempts to pinpoint the exact origin and justification for the chosen private IP address ranges. While some initial speculation points to Sun Microsystems' use of 192.9.200.x in early documentation, the consensus shifts towards more formal explanations.

  • "Someone purported the origin to be Sun but it turned out they used a different address in examples." (rzzzt)
  • "The number of people who had copied Suns (and HPs and others) addresses out of the docs was enormous." (nickdothutton)
  • Crucially, Daniel Karrenberg, a co-author of RFC1918, provides a detailed account: > "The RFC explains the reason why we chose three ranges from 'Class A,B & C' respectively: CIDR had been specified but had not been widely implemented. There was a significant amount of equipment out there that still was "classful"." > > "As far as I recall the choice of the particular ranges were as follows:" > > "10/8: the ARPANET had just been turned off. One of us suggested it and Jon considered this a good re-use of this "historical" address block." > > "172.16/12: the lowest unallocated /12 in class B space." > > "192.168/16: the lowest unallocated /16 in class C block 192/8." > > "In summary: IANA allocated this space just as it would have for any other purpose. As the IANA, Jon was very consistent unless there was a really good reason to be creative." (isThereClarity)

This authoritative quote highlights that the choices were largely pragmatic, aiming to reuse existing large blocks, particularly the decommissioned ARPANET block (10/8), and select the "lowest unallocated" blocks within the classful A, B, and C address spaces that had not yet been widely allocated.

The "Paving the Cowpath" Argument: Did Private IPs Hinder Internet Evolution?

A counter-narrative emerges, suggesting that the introduction of private IP addresses and Network Address Translation (NAT) might have been detrimental to the internet's long-term development, particularly regarding IPv6 adoption.

  • "The optimist in me wants to claim that not assigning any range for local networks would have lead to us running out of IPv4 addresses in the late 90s, leading to the rapid adoption of IPv6, along with some minor benefits (merging two private networks would be trivial, much fewer NATs in the world leading to better IP based security and P2P connectivity)." (wongarsu)
  • The core of this argument is that private networks break the assumption that every device on the internet has a globally unique, reachable address. This necessitates NAT and firewall configurations, which can be complex. > "Private networks break this assumption. Now we have machines which can send packets out, but can't receive packets, not without either making firewall rule exceptions or else doing other firewall tricks to try to make it work. Even then, about 10-25% of the time, it doesn't work." (emacsen)
  • This perspective argues that the widespread reliance on NAT created a "perpetual limbo" and delayed the inevitable transition to IPv6. > "We'd also have seen fast adoption of IPv6 when IPv4 ran out. Instead we seem to be stuck in perpetual limbo." (emacsen)
  • "This is probably an example of paving the cowpath." (dreamcompiler) - This quote encapsulates the idea that a workaround (private IPs + NAT) became the entrenched solution, preventing a potentially more direct or cleaner path (like earlier IPv6 adoption).

The Pragmatic Benefits and Necessity of Private IP Ranges

In direct response to the "paving the cowpath" argument, many users defend the necessity and benefits of private IP ranges, emphasizing their role in making IP networking accessible and manageable.

  • The primary benefit is the conservation of limited IPv4 address space.
  • They simplify network management for most users and organizations. > "I think nearly everyone would go for IP over using something other than IP. Nobody misses the days when the printer you wanted to buy only spoke AppleTalk and you were using DECnet." (tzs)
  • The alternatives to private ranges would likely lead to their own complications, such as ISPs charging per IP address or forcing users to manage unallocated public IP blocks, which would still require NAT or similar mechanisms. > "If we use IP but do not have assigned addresses for each device and did not have the private ranges I'd expect most places would just use someone else's assigned addresses, and use router/firewall rules to block them off from the outside." (tzs)
  • The standardization of private ranges, even if reactive to common practice, prevented the chaotic use of arbitrary "squatted blocks." > "If the private ranges were not standardized then people would still have created private networks, but just used some random squatted blocks. I can not see that being better outcome." (zokier)

User Experience and Network Management with Private IPs

A significant portion of the discussion also touches on the practicalities and occasional annoyances of using private IP addresses in daily use, particularly concerning device naming and port management.

  • DNS Aliasing and Naming: Users discuss various methods for aliasing private IP addresses to more memorable names for easier access to local network devices.
    • /etc/hosts is mentioned for *nix systems.
    • mDNS (Multicast DNS) is highlighted as a more robust solution that works across different operating systems. "mDNS works well for names on your local network, you can integrate it with your dhcp server, works on hosts and phones." (jerkstate)
    • Using a subdomain of a real domain for LAN gear and managing DNS records (e.g., with Route53) is another proposed solution. "I just stick all my DNS records in a normal DNS server. In my case Iā€™m terraforming some Route53 zones." (akerl_)
  • Port Management: The challenge of remembering and managing ports for various services is also raised.
    • SRV records in DNS are theoretically designed for this but are noted as not being widely used. "Theoretically SRV records can be set in dns to solve the port issue, realistically Nothing uses them so...." (somat)
    • SVCB/HTTPS records are mentioned as a more modern approach for services running on the same IP. (denkmoon)
    • Running services on standard ports (like 443) and using reverse proxies (like Nginx) is a practical workaround. (akerl_)

Hacker News Interaction Dynamics: Downvoting and Deleted Comments

A meta-discussion emerges regarding Hacker News's comment and moderation practices.

  • The intended versus actual use of the downvote button is debated, with some referencing Paul Graham's past statements. "That's how I think it should be, but Paul Graham disagrees (or at least he did in 2008..." (tzs)
  • The disruption caused by deleted comments is pointed out, leading to a call for quoting replies for context. > "It also disruptive to anyone who comes here and sees replies to a deleted comment and can't see the context." (marcusb) > "Amen. I try to quote what I'm referring to for just this reason." (michaelcampbell)
  • The act of flagging certain comments is also observed. "LocalH: flagged for removing useful content for the discussion thread"

Historical Context and Nostalgia

Some participants reflect on the history of the internet and express nostalgia for its earlier days.

  • "Reading this makes me a bit sad and reminds me that I'm older now and lucky to have grown up during the golden age of the Internet." (morning-coffee)
  • The mention of Jon Postel evokes a sense of reverence for his contributions to the internet's infrastructure. "I had never heard of Jon Postel before now." (Sharlin)

Obscure and Alternative Private IP Usage

The discussion also touches upon less common or historical uses of IP space for private networks.

  • The use of 127.26.0.x as a private network range is mentioned as a personal experience that caused issues upon joining a university network. (alvarete)
  • The loopback address space (127/8) is noted as technically being reservable for private use, though not commonly implemented as such. (dragonwriter)
  • A anecdote recounts a customer using IP ranges typically seen in North Korea for their internal network. (michaelcampbell)
  • A workplace still actively using the 192.9.200.x subnet, attributed to a vendor from the 90s, is also mentioned. (zettabomb)