I'm running Geth 1.4.15 (just released),and trying to sync the blockchain. For some reason, I always get this "DAO-fork dropping" error message when these spam attacks are occurring. I wanted to know if this is what everyone sees or if I have a unique problem that I can fix.
Here's the terminal screenshot: https://i.sstatic.net/9Ht23.jpg
This is a message that everyone sees. You can safely ignore it.
From Problem syncing timed out DAO fork-check, dropping #2857 , @karalabe states that:
The "timed out" log is just a log anomaly (I forgot to top the timer if the peer disconnect before finishing the DAO challenge (e.g. remote side finished challenge and deemed to disconnect)). You can disregard it.
As for getting behind, I did find a bug (it was introduced quite some time ago, back in the EDGE release) that causes bad peers not to be dropped. It can lead to stalls in certain scenarios. This is also fixed on develop.
I'm further writing up two more patches to the downloader to make it less resource intensive and more flexible.
