Sunday, May 10, 2009

The WS-C3524-XL isn't a good choice for CCNA practice anymore.

I am in the process of studying for the CCNA and I have a Cisco 3524 in my arsenal that I got for cheap before I really had an idea of what gear to buy. It is nice to have the switch around to complete my three switch lab configurations, but as I get deeper into my studying I am finding that there are some significant differences between the 3524-XL and newer Cisco switches that can make using this switch a bit of a headache. The problem is that this switch is EoL and Cisco stopped supporting this switch in IOS 12.0. Presumably these shortcomings apply to the 3548-XL and 2900-XL devices as well. For the sake of comparison, my other switches are 2950s and 3550s, which are much more capable/recent. here is a list of shortcomings that I have identified thus far; I will update the list as I find more.

  1. VLAN database - The newer IOS versions place VLAN and VTP configuration inside of configuration mode; namely the vlan and vtp global commands. At first glance, these commands appear to be missing from the 3524 interface, but really they are just placed elsewhere. These commands are located in the vlan database privileged-mode interface. Access this mode and you can configure VLANs and VTP to your hearts content. The command syntax is mostly the same too.
  2. switchport nonegotiate - This command does not exist on the 3524 IOS.
  3. switchport mode dynamic - This command does not exist on the 3524 IOS. Your choices are trunk or access. You also can not connect a 3524 trunk port to another switch (2950 in my case) configured for a dynamic mode. The other switch will freak.
  4. switchport voice - The 3524 does support this command, but it does not appear to work properly. I connected [linux] notebooks to voice ports on a connected 3524 and 2950 and configured 802.1q tagging interfaces. The tagged IP addresses could not communicate, but the untagged (access) IP addresses could. Repeating this with a 2950 and 3550 connected works just fine for tagged and untagged frames. I was able to approximate the behavior by setting the 3524 port to trunk mode, but this would probably not be acceptable in a prduction environment.
  5. show interface trunk - This very useful troubleshooting command does not exist on the 3524 IOS.

There are probably more I have forgotten. Bottom line, the 3524 and similar switches are okay for an extra switch if you can get them dirt cheap (<$50), but don't buy them with the expectation that you will be able to study everything on the ICND2/CCNA exam.


  1. Excellent article. Thank you so much :)

  2. What switch for ICND2/CCNA you recommend?

  3. I'm not sure what would be a good recommendation for the current iteration of the CCNA. When I was studying for the certification, I found the WS-C2950-24 to be a good fit, and pretty reasonably priced.