possible SYN flooding on port 80. Sending cookies. -

possible SYN flooding on port 80. Sending cookies.

Errors like this are shown on high usage servers and ports so it is common to see it on http and even imap ports:

possible SYN flooding on port 80. Sending cookies.

The Linux kernel will even detect flooding on OpenVZ containers:

possible SYN flooding on ctid 6000, port 993. Sending cookies.

In many cases this is not an issue and is more so simply a result of regular, but high usage traffic.


  • zip warning: name not matched: in Linux Solution
  • ls in Linux with full directory path with files howto
  • bash how to check if a symlink exists as a file or directory
  • css .ul and .li how to remove the identation padding/margin from list items?
  • how to extract .xz file in Linux Centos/Debian/Ubuntu
  • Linux how to whois query other gTLDs such as .club solution
  • How to verify SSL SHA-1 Certificate Fingerprnit Signature of your mail/web server to avoid hijacking/man-in-the-middle attacks
  • Linux Ubuntu Mint how to view RAW image files .arw?
  • ecryptfs errors
  • What happens when you unplug 1 or more devices from an mdadm RAID array to simulate a failure in Linux Ubuntu/Centos/Debian?
  • Migrating from Linux Mint 17.2 mdadm RAID array to a new one (because I upgraded to larger drives).
  • Linux how to reformat html file code solution
  • ENOM how to do a 301 redirect to another domain/site
  • ENOM TRANSFER passwords do not match - solution
  • Linux how to check http headers using bash/curl for SEO
  • mdadm: CREATE group disk not found Incrementally started RAID arrays. Incrementally starting RAID arrays...
  • Linux SAMBA does not work with symlinks
  • How to Execute PHP in .html files with Apache in Linux Centos/Debian/Ubuntu etc
  • mdadm how to recover from failed drive
  • yum Packages skipped because of dependency problems: