Regrettably, at this time sks.undergrid.net will be going offline indefinitely. My wife and I are in the process of selling our house in Georgia and moving to Florida. In preparation, I've been moving most of my services I need to keep available into the cloud. Unfortunately due to the usage/abuse pattern of the key server network and the resources required to adequately operate the server cluster I can not justify the cloud expense at this time. I do hope to get the key server cluster back online eventually but will have to wait until a later date.
If you have sks.undergrid.net peered in your membership file please feel free to remove or comment out. The servers are currently offline and have suffered from poor performance for a while now.