CCNA Lab Part V: Ruling Out (or In) 2500 and 2600

Are the Oldies of the Used Cisco Router Market Still Goodies?

Cisco 2500 and 2600 series routers have long been some of the favorite router models for cost-conscious Cisco cert candidates looking to build a lab. They were cheap, they worked, and there was a seemingly endless supply in the used market. But they both only support IOS images through 12.2T/12.3. Today, I'll continue this series on building a CCNA lab, and look at the question of whether these two model series are still viable for CCNA study today.

Before embarking on anything that drives towards suggesting a particular thing to buy, let me set some expectations.  First, while I believe everything I post here and at certskills.com is correct, there may be errors; there is no warranty as to the accuracy of what's here. (I'm always happy to hear comments/corrections in that regard.) Also, the pricing I reference is done for comparison, but I'm sure you'll see different prices when you shop. (We just check prices each year, the same way every year, so that it's apples-to-apples over time.) Finally, I'm assuming that you're buying for CCNA, with out consideration of the next certification. You might make different choices depending on your next cert. It's just too many variables to toss out while also keeping this relevant to newbies. That's it!

CCNA 1998 vs. CCNA Today

To make the case about whether 2500s and 2600s make sense for CCNA today, you need to think about what's needed for CCNA today. I remember being at the Cisco Networker's show in 1998 where Cisco announced CCNA (and CCNP) to the world. (I think it was in Philly, back in the days where Cisco had two Networkers shows in the USA each year.) Anyway, thinking back to those days, some of the topics in the original CCNA exam were:

  • Router admin (passwords, hostnames, CLI navigation)
  • IP Addressing
  • Static IP routing
  • RIP (Version 1)
  • IGRP
  • PPP
  • Frame Relay
  • NAT/PAT

So what's really changed until now? Although Cisco doesn't give the CCNA version numbers, the current CCNA exam (640-802, 2007) is essentially the 5th iteration of the CCNA. Cisco has tweaked the scope of CCNA topics each time they changed the exam. Comparing the original CCNA to the current exam, RIP is now RIP Version 2, which adds 1 configuration command. IGRP has morphed into EIGRP, which configuration-wise is very similar. PPP and Frame Relay remain substantively unchanged. The current CCNA adds OSPF, although the configuration is relatively basic compared to all that OSPF can be made to do. And Cisco has added some other topics over the years, including IPv6, using a graphical tool (SDM) to configure some features.

While this walk down memory lane may be interesting, I do have a reason to mention these points of comparison between the original CCNA and today's CCNA. If you went and bought a router that was useful in 1998 when CCNA came out, you'd probably be able to do half, or maybe a little more, of the commands you'd need to practice for today's CCNA. There's still a fair amount of overlap between the original CCNA and the current CCNA exam.

So, in this context, when buying CCNA lab gear, don't automatically think that old is bad - just think that old is marginally worse.

Baseline: 2501, 12.2T/12.3 IOS, IP Feature Set

For this discussion, I'll consider the usual culprits, the usual router model series whose feature I summarize at certskills.com. These include the really old 2500 series, and the old 2600 series. Also, to define terms, "2600" means the older 2600 series without the "XM" designation, with "2600XM" referring to the newer 2600 series that does have XM in the name. That is, 2600 is a different series than 2600XM.

For comparison's sake, I'll start with the oldest model series - 2500s - and look at what you get with the most common model (2501, with the latest T-train release (12.2T), with the most basic feature set (IP)). Then we can compare that option with other models, later IOS versions, and other feature sets.

If you bought a 2501, you would get 2 built-in serial interfaces, plus 1 Ethernet interface that requires an external transceiver. It's not that hard to find them in the used market, with 12.2T loaded. Assuming that IOS was the most basic feature set (IP), the question is, what could you do for CCNA?

Whatever that is, I'll call that our "baseline" for today's post. So, what is that baseline?

  • Router admin  (passwords, hostnames, etc)
  • IP Addressing
  • Static routes
  • RIP-2
  • EIGRP
  • OSPF
  • PPP
  • Frame Relay
  • NAT/PAT

More importantly, what's not in the baseline that matters for CCNA?

  1. SSH
  2. SDM
  3. IPv6

Can you Get the Rest of These Features in 2500/2600?

You can get this baseline set of features on that 2501, with the least functional feature set at version 12.2T. (Likewise, with a 2600 and the same IOS version/feature set.) If you look at the list of what's missing from that really old 2501, at least for CCNA, it's not a lot. SSH matters, but it's a relatively small part of CCNA. SDM matters, but it's a GUI that for CCNA you might use to configure NAT or DHCP - and GUIs should be intuitive if you know the underlying feature. IPv6, well, that's one that I'd personally want to practice.

So, how do you get the rest of the CCNA features - and can you use the older and cheaper 2500 and 2600? Unfortunately, it's not as cut and dried and we might prefer, particularly if you need to be cost conscious. So let's walk through each of these features.

Adding SSH

To get SSH, you can actually get some support in 12.2T  (according to the Cisco feature navigator), as long as you get a better feature set. But to enable SSH on the VTY lines using the transport input ssh command, so you can test with SSH into the router, you need to get to 12.3T/12.4 mainline.

To get 12.3T/12.4, that rules out the 2500s and 2600 (non XMs). That leaves you with the other four model series I'm considering in this series (800, 2600XM, 1700, and 3600 (specifically 3640)). To get SSH support, according to the Cisco Feature Navigator, you can get SSH in several feature sets, including IP or IP Base. (If there's anyone out there with a 12.3T/12.4 mainline IOS with feature set "IP" or "IP Base" that can test/confirm, please post!).

Finally note that to practice SSH, you really just need it on one router, in case you're thinking of saving money.

Adding SDM

To get SDM support, it's the same story as SSH: you need 12.3T/12.4 IOS, with lots of feature sets supporting it (per Feature Navigator), including IP/IP Base. So, if you want SDM, then ignore the 2500/2600 non-XMs again. And again, you really only need one router to support SDM for what you need to practice for CCNA.

Adding IPv6

The question of IPv6 support muddies the water quite a bit. To get full IPv6 support, you need 12.4T. Having 12.4T rules out not only 2500s and 2600s, but also the3640, leaving us with the 1700 and 2600XM series. However, that's not the full story on IPv6.

While CCNA includes coverage of IPv6 today, that coverage doesn't include the equivalent scope of topics compared to IPv4, at least if you use my ICND2 book as a standard. CCNA IPv4 coverage includes IPv4 addressing, static routes, RIP, EIGRP, OSPF, NAT, and ACLs. Instead, CCNA focuses on IPv6 address configuration and RIPng. I expect that over time, Cisco will add more and more IPv6 commands to CCNA, but for this version, it's not a lot of IPv6.

Additionally, "IPv6" is not a single feature in IOS, added at a specific IOS version. Historically speaking, Cisco added major pieces of IPv6 support over several IOS versions - ironically, the three major releases most likely to be considered for a used Cisco lab today. Cisco's IOS IPv6 support goes as far back as 12.2T/12.3, which included IPv6 addressing and RIPng. 12.3T/12.4 added OSPFv3 (OSPF Version 3 was created specifically for IPv6). 12.4T/15.0 added EIGRP for IPv6.

Finally, while I've seen IPv6 and RIPng configured on a 2501 router, Cisco's feature navigator claims it's not there. So, I'd be a little doubtful of whether you could get IPv6 to run on just any 2500 you buy. I'm running an Enterprise feature set on the 2501 on which RIPng was working.

What does this mean to you when choosing a CCNA lab? Well, you could choose to look for gear that supports 12.4T, and be confident of its support for all IPv6 features, and that all the show commands list meaningful output. Or, you could go for a 2600, with older IOS versions, with just enough IPv6 to practice for CCNA.

(Aside: I hadn't played with IPv6 on those earlier versions a lot to be honest, so I just tested for about a half hour. IPv6 addressing and RIPng configuration worked just fine for me on a 2600 non-XM and a 2500 router running 12.3 mainline.)

Note that the IPv6 support typically does require a better feature set than IP base - check feature navigator to make sure. For instance, a 2600 with IP Plus at 12.3 should have IPv6 addressing and RIPng support.

Conclusions: How to Make a 2500/2600 Work Best for CCNA

So, can you still use these old routers? Sure. And get most everything you need for the exam. Here's the plan to make best use of them.

For 2500s:

Buy your routers with 12.2T or 12.3 mainline

Get a feature set that would support IPv6 on a 2600; maybe it'll actually run IPv6

For 2600s:

Buy your routers with 12.2T or 12.3 mainline

Make sure the IOS feature set supports IPv6 and RIPng; "IP Plus" is a good candidate

Both 2500 and 2600:

                  No SDM, no SSH

As for the two features you just don't have access to with 2500 and 2600, you have two options:

  1. Don't bother practicing with SDM and SSH
  2. Buy one router that supports a later IOS with support for SDM and SSH - maybe even get one that ran 12.4T.

(final aside: I list a lot of these CCNA features, IOS versions, feature sets that support them, etc, based on culling through feature navigator, at this web page - FYI.)

Related Posts:

CCNA Lab Series 2011: Overview

CCNA Lab II: How Topologies Drive Device Choices

CCNA Lab III: Sifting Through the Router Model Series

CCNA Lab IV: Choosing the IOS Version and Feature Set

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