Cisco Switch and Network Configuration FAQ

[Bruce Wilkinson]

The "User Manuals and Application Notes" section of our web site (found here http://www.axiaaudio.com/manuals/default.htm) contains tech notes on the configuration of specific Cisco Switches. These are intended as guides however most installation are unique in some respect so we encourage you to contact our Technical Support group if you have any questions. This topic will address a few general questions related to our recommended network configuration.


Do we need special configurations for Cisco switch ports used for PC's?
All ports should be configured the same when talking Livewire and there will be no difference between Axia devices and computer players. The only difference in configuration is IF you connect a switch to another switch. You will need to have only those specific ports use the "Configuring ports connecting to other CISCO Catalyst switches" portion of the switch configuration document.

What version of Cisco software do I need? Cisco software versions 12.2 (25) SEA or higher in either IP Services or Basic IP Services (IPBASE) software have been tested and approved for use with Axia Livewire. Older versions may not support all of the features we require. Also, remember that not all Cisco switches are capable of supporting IGMP and other features that we need so be sure to get some advice before purchasing a switch for your Axia system. Some basic info on this topic can be found here http://www.axiaaudio.com/switches/default.htm

Can I use an HP 2626 switch or do I have to use Cisco?
You should always use a switch that has been qualified for use with Livewire. This list will always be available on our web site. While we previously recommended the HP 2626, we have since found that it it not compatible with Cisco core switches and unfortunately, it doesn't look like that will change. That said, there are quite a few small systems in use today that have been running just fine for a few years with HP 2626 switches. In summary - a new system should always use recommended Cisco switches. That way you are able to expand if necessary plus you will be able to benefit from our experience with the configuration of these switches.

Why does Axia recommend Cisco EMI switch software versus SMI?
Many Cisco switches are available with either the standard multilayer software image (SMI) or the enhanced multilayer software image (EMI). The SMI feature set includes advanced QoS, rate-limiting, ACLs, and basic routing functionality. The EMI provides a richer set of enterprise-class features, including advanced hardware-based IP unicast and IP Multicast routing as well as policy-based routing (PBR). While SMI-equipped switches perform well in systems of limited scale, EMI provides better performance in larger systems where more audio routing occurs. If you have questions, feel free to contact our support group bu email - support "at" axiaaudio.com. More info on our Cisco recommendations is found here. http://www.axiaaudio.com/switches/default.htm


Etherchannel example - Cisco 4948 Core Switches
This note provides an example of how to setup Etherchannels on a pair of ports connecting 2 x 4948 core switches, each with its own unique IP address. Lets say you want to have ports 1 and 2 setup as etherchannels. What you will do is set these ports up as normal trunk ports with the 4948 configuration which looks like this:

• config t
  interface range gigabitethernet 1/1-2
  switchport trunk encapsulation dot1q
  switchport mode trunk
  switchport nonegotiate
  switchport block multicast
  switchport voice vlan dot1p
  qos trust cos
  tx-queue 1
  shape percent 25
  tx-queue 2
  shape percent 25
  tx-queue 3
  priority high
  tx-queue 4
  shape percent 10
  end

This puts all the commands to talk to another switch in place. But etherchannels make it so that you will actually "gang" these ports together and the switch actually does load balancing with any traffic that must traverse the two core switches. If you just have the above config in there then the switch will do none of this fancy stuff. It will only be connected to the other switch in two locations and it will pick the first port (or just any port) put it in the ARP table and any traffic that must traverse will only go out that one port and the other will not even be seen because the switch thinks that there is already a connection to the other switch, "why do I need another one" and ignore it. This normally is no big deal but when you have more then 1GB of Axia/LW traffic that needs to go from one switch to the other with UDP, then this could be a HUGE problem. You then tell the switch to group the ports together and do all the fancy etherchannel stuff with the following commands:

• config t
  interface range gigabitethernet 1/1-2
  channel-group 1 mode desirable
  end

This will make the switch see both ports equally and distribute the traffic logically between both ports. Unlike all the other commands that show up in a "per port" list, this etherchannel setup shows up like the global commands at the beginning of any other switch that we use or the IP address setting at the bottom of the normal configs for VLANs.