January 31, 2007

Primary Data Center Switch Upgraded to Gigabit Ethernet

Filed under: Networking,T3city — pj @ 4:14 pm

We’ve been meaning to upgrade our switches to GigE for some time. Last week, I swapped out our trusty Cisco 2924 switch with a NetGear GigE Prosafe Smart Switch. So far, so good on the NetGear switch.

The web UI is a little clunky, but overall, it’s better than most other switch configuration UI’s I’ve used in the past. I still prefer a script based configuration, but you don’t get that in these lower cost “web managed” switches.

The switch’s rules for VLANs are a bit weird. For example, I don’t like the “default VLAN” concept they have implemented. Also, you can’t mix tagged and untagged traffic on a single port (as you can with most hosts and many other switches). Really, VLANs are simple. A packet can be VLAN tagged or untagged. A switch port can be granted access to 1 or more VLANS. For each VLAN for which a switch port has been granted access, the port can either tag or not tag outgoing traffic. That’s it. I can see why the default configuration of a switch should be to grant very port untagged access to VLAN 1, but that doesn’t imply to me that there needs to be some kind of “default” VLAN for each port.

The switch’s management IP does not have to be on VLAN 1. This is a nice touch that I appreciate.

The statistics in the web GUI are pretty sparse. You can view basic interface counters for each port. It would be nice to get some idea of the bandwidth in use on each port. The 5 minute input and output rates on Cisco’s “show interfaces” output is a good example of what is useful.

SNMP support is also basic, but I had no problem configuring Cacti to create traffic graphs for each port. That is all I need.

Jumbo frame support is either on or off. Most switches let you set this per port. Setting it per VLAN would make the most sense to me. But, unless you could program the switch to automatically fragment packets for hosts that don’t support jumbo frames (and what switch does this?), a global switch is fine. Ultimately, you have to deal with the individual hosts on each VLAN – support for jumbo frames on the switch is just a simple yes or no (and can probably always be set to yes as long as the switch itself does not generate any jumbo packets).

The switch supports trunking. That is fairly common for switches that support VLANs. I haven’t tried out trunking. A GigE pipe is big enough for me right now.

You can have up to two ports configured to monitor (sniff) traffic on other ports. I haven’t tried this out yet, but I’m sure it will come in handy when one of our beloved unmentionable security agencies hits me with a court order for eavesdropping.

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