I decided to test my newly acquired 2970G switch this weekend by organizing a LAN party at home. Eventually about eleven people showed up, all with a desktop or laptop with a gigabit card. Time for testing! And gaming of course.

Biggest problem was not the lack network speed, games, food, or alcohol, but the room for all those computers, and more importantly, power requirements. My house has old power lines and one single outlet can barely support a high-end gaming ridge, so I had power cables running from parts of the house that I know can sustain more devices.

Network freak as I am, I logged in from time to time on the switch to check network health, both for monitoring and troubleshooting some connections. Using ‘show interface GigabitEthernet0/x’ I noticed some devices did not negotiate gigabit speed, but only up to 100Mbit full duplex. In some cases this was due to my poor cable patching skills, in others the prepatched Cat6 cable simply could not handle gigabit speed. Luckily, some of my own patched cables did go to gigabit without problems, so I’m not a total failure on that part.

A second thing which I monitored was switch conditions: it was placed in the middle of the room with enough room for ventilation, but I had doubts considering it was a hot day. More recent Cisco switches luckily have a temperature and power sensor build-in, which you can poll with the ‘show env all’ command. I also checked for CPU usage: since everything was in the same VLAN, no routing and processes requiring the CPU should be involved, as a Cisco switch handles all switching in hardware. (This is one of Cisco’s flag technologies, and they like to brag with it against competitors switching in software. Whether it’s really better, I will explain in one of my blog posts in the upcoming weeks.) A ‘show processes cpu | include CPU’ will show the usage, which idled at 4-5% the entire time. The ‘show processes cpu history’ command gives a more visual output, with an ASCII generated graph showing maximum and average CPU load.

We were also ‘lucky’ enough to see what a malware-infected computer will do on a layer 2 subnet. We noticed the computers becoming slightly less reactive at one point, shortly after a new computer was plugged in. Eventually I could track down the issue to excessive broadcasts caused by the new device, using ‘show interface GigabitEthernet 0/x | include broadcast’, after which Wireshark confirmed something was indeed going on.

File sharing went great. Most transfers reached about 480 MBit, exactly the theoretical maximum for the USB2 interface used by the external hard drives. One transfer between internal hard drives peaked out at the full gigabit, transferring 5GB in about a minute. Numbers not seen on a home network running +10 computers normally. Gaming was also great, with sub-millisecond ping times most of the time. The only trouble I ran into was the typical Windows Firewall issues, and the occasional headshot ingame. Some games did seem to make a fuss out of having multiple network cards, even when told which one to use. I also had IPv6 running (because I can) but none of the games had any awareness of that, though Windows Samba shares did seem to take advantage of it by occasion.

All in all a great LAN party, no regrets from the switch I’ve bought, and maybe I’ll organize one again in the future.

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