The previous article examined a couple of basic Large Scale NAT (LSN) architectures – NAT444 and NAT464 – for creating dual stacked networks in the face of a depleted IPv4 address pool. The focus is primarily on broadband service providers, who must somehow continue to assign addresses to very large numbers of new customers when there are no new IPv4 addresses to use. Assigning IPv6 addresses alone is not practical for two reasons: Read more
Traditional NAT, as discussed in the previous article, has been used for fifteen or so years to enable the sharing of a small number of public IPv4 addresses by a larger number of privately-addressed devices. In the case of homes and small businesses, there is usually just a single public IPv4 address on the outside NAT interface. That public address is assigned by a broadband service provider. Read more
Any general-use IP protocol stack that supports IPv6 also supports IPv4. That is, it is dual stack capable. “General-use” is an important qualifier here: Certainly there will be specialized devices that support only IPv6. But these devices – until we get to some unspecified time in the future where IPv4 no longer exists – function in “walled garden” applications such as sensor or control networks that have distinct boundaries and never interact with IPv4. Read more
We are entering the transitional period between IPv4 andIPv6, and things are going to get awkward for a while. IPv4 addresses will officially be used up in the next couple of years, although for most practical purposes you can consider the pool of unallocated IPv4 addresses to be depleted already. I know of two very large service providers whose requests for new IPv4 allocations were, in the last couple of months, denied.
The “awkward period” we are entering is caused by several unavoidable facts: Read more
One of my favorite stories (stop me if you’ve heard this one before) concerns an aged power station. One day the station failed, leaving the small town it served completely without electricity. The town managers called in several engineers, none of whom could resolve the problem – the station’s equipment was older than anything they had worked with before.
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Over the past several posts I’ve been discussing how networkers can reduce supposed “immeasurables” or “intangibles” to something that can in fact be measured, and I’ve been using Douglas Hubbard’s excellent book How to Measure Anything: Finding the Value of Intangibles in Business as a guide. I highly recommend that you pick up a copy of the book if you want more details about the approach I’ve been discussing. Read more
In the previous post I wrote about the difficulty – quite common among networking and IT engineers – of expressing concepts that we understand in quantifiable terms that have meaning to the CFO or anyone else who must fund our projects. Read more
I’ll get back to the discussion of quantifying intangibles in a couple of days, but I wanted to let you know that I have joined Synergy Research as a Vice President of Research, focused on IP Infrastructure and Metro / Carrier Ethernet. You can read the announcement here. Read more
It’s been a long tradition around our house that I cook the Christmas dinner. I enjoy cooking but don’t get the time to do it as often as I would like; my wife does the great majority of day-to-day cooking, so she enjoys not having to cope with the Christmas feast. Read more
2008 was sort of a milestone year for IPv6. Foremost there was the much-touted US OMB Mandate which everyone got excited about back about 2005: By June of this year all federal agencies’ “infrastructure (network backbones) must be using IPv6 and agency networks must interface with this infrastructure.” In the years between that mandate and the deadline, however, the language and requirements slipped significantly. Read more
I picked up a G1 yesterday. It was a big step for me, because I’ve never really wanted a mobile phone that does more than make phone calls (and text messaging, since my teenagers seem to have lost the ability to communicate by any other means). When I was at Juniper, my boss and I fought a running battle for years: He wanted me to carry a Blackberry, and I didn’t want to be anywhere near that accessible. Read more
For all the harping I do on this blog about IPv4 address depletion and the need to prepare yourselves for IPv6, there is another number resource that is also being quickly depleted, and that I haven’t written about before: the 2-byte autonomous system numbers (ASNs). Read more
My last post talked about the need for enterprise network operators, even if they think they will not need IPv6 for their internal networks in the foreseeable future, to take into account their public-facing servers. Although there are few IPv6 users trying to reach those servers at present, their numbers will grow over the next few years. You need to be ready to serve them. Read more
If you have followed this blog for very long you know that I post pretty regularly (far too regularly, some might say) on the fast-approaching depletion of the remaining pool of public IPv4 addresses.
If you haven’t followed this blog before, I’ll give you the short version: Read more
“High availability” has been a technical and marketing buzzword for a number of years, and lately infrastructure equipment vendors have made “HA” a feature set. In that regard HA has come to mean a combination of hardware and software that reduces device downtime. In this age of “five nines” reliability and stringent Service Level Agreements, pretty much any downtime is unacceptable: If a device is out of service for more than about 315 seconds in a year, it is below the 99.999% threshold. Read more
In the previous post I discussed how the Internet influenced the American presidential election. (Okay, okay, how in my opinion it influenced the election.) In this post, I'd like to flip the discussion to how the Internet might be influenced by the newly elected administration.
Network World is already carrying several good articles along these lines. Scott Bradner's is particularly good. Read more
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I debated whether to write this post at all. Doing so means letting some of my political views show, and I wasn’t sure whether that would be appropriate for this blog. But in the long run it’s really about the industry we all work in to one degree or another, so here goes… Read more
I wrote in the previous post that many network executives resist IPv6 deployment because they cannot find a means to make it profitable. This is a misguided viewpoint, because IPv6 is an infrastructure issue, not an applications issue. Read more
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In the years of trying to convince network operators and executives of the urgency behind getting started on an IPv6 implementation plan, those resistant to the idea usually give me one or more of the following: Read more
Jeff Doyle is president of Jeff Doyle and Associates, an IP network consultancy. Jeff is the author of Routing TCP/IP, Volumes I (read an excerpt) and II and of OSPF and IS-IS: Choosing an IGP for Large-Scale Networks. He is a frequent speaker on IPv6, MPLS, and large-scale routing.
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