alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET INFO External IP Check myexternalip.com"; flow:established,to_server; http.method; content:"GET"; http.host; content:"myexternalip.com"; startswith; endswith; classtype:external-ip-check; sid:2019980; rev:7; metadata:created_at 2014_12_20, confidence High, signature_severity Informational, updated_at 2024_04_13;)