There are signs of SYN flood attack, and the engineer should increase the backlog and recycle the oldest half-open TCP connections.

There are signs of a malformed packet attack, and the engineer should limit the packet size and set a threshold of bytes as a countermeasure.

There are signs of a DNS attack, and the engineer should hide the BIND version and restrict zone transfers as a countermeasure.

There are signs of ARP spoofing, and the engineer should use Static ARP entries and IP address-to-MAC address mappings as a countermeasure.