Squid - Alerts - SURICATA UDPv4 invalid checksum

Disable Hardware Checksum Offloading under System → Advanced → Networking.

Suppress Rules

# Messes up with DNS resolution on LAN.
1:2200073 # SURICATA IPv4 invalid checksum
 
# Bittorrent noise, DNS.
1:2200075 # SURICATA UDPv4 invalid checksum
1:2200078 # SURICATA UDPv6 invalid checksum
 
# Lots of useless noise.
1:2200076 # SURICATA ICMPv4 invalid checksum
1:2200079 # SURICATA ICMPv6 invalid checksum

NOTE: Try toggling the Hardware Checksum Offloading.

If that does not do it, you can simply disable that particular rule by either clicking the red X icon on the Alerts tab in the GID/SID column, or you can find and selectively disable that rule on the Rules tab for the interface.

See this thread from the official Suricata documentation Wiki for details:

http://suricata.readthedocs.io/en/latest/performance/packet-capture.html.

Suricata uses PCAP for packet capture during Legacy Blocking Mode operation, and Netmap for Inline IPS Mode operation.

In both cases, hardware checksum offloading needs to be disabled.