Problem with halting large filetransfers solved
This post is over 5 years old, it may be out of date.
Next Thursday morning, April 24 the ISC network admins will change a setting in the RU-firewall, as a result of a few reported problems with halting transfers of large data files. The firewall does TCP Sequence Number Randomization for security reasons. Therefore TCP SACK will be disabled in the firewall, which makes modern hosts that use SACK no longer having halted connections through the firewall.