Http traffic partially dropped

Hi everyone,

I am a CS student and new to Suricata. Currently i’m working on a sensor which has got an Intel(R) Core™ i7-3612QE CPU @ 2.10GHz, 16 GB of RAM and 4 Intel NICs. With TRex traffic generator I create dummy traffic (malicious, licit or both) to test the amount of load my sensor can handle in terms of signatures detected. During some tests, unfortunately, I stumbled on an issue.

When generating 200Mb/s or more of traffic of different types, http traffic is partially dropped.

However, by inspecting the suricata generated logs no drop is visible either kernel or NIC side.

The only evidence I got is the tcp.reassembly_gap which is not 0 and the number of signatures which is not what i expected.

From chapter 9.6.2 of Suricata documentation I understood that this might be due to packet loss, bad checksum or stream engine running out of memory.

However checksums are not evaluated (I disabled it in the configuration file) and there’s plenty of memory suricata can use.

Strangely enough, another signature on the same traffic but related to TCP protocol showed up as I expected.

So, is there something I am missing? I would like to gather more information, how could i do that?

See below my configuration and signatures.

Signatures:

alert tc
[test_my_nids.pcap|attachment](upload://epGt3Kkrf0m11pJx06YxqkQrWNs.pcap) (1.6 KB)
p any any -> any any (msg:"GPL ATTACK_RESPONSE id check returned root(tcp)"; content:"uid=0|28|root|29|"; classtype:bad-unknown; sid:2100498; rev:7; metadata:created_at 2010_09_23, updated_at 2010_09_23;)

alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET POLICY curl User-Agent Outbound"; flow:established,to_server; http.header; content:"User-Agent|3a 20|curl/"; nocase; reference:url,www.useragentstring.com/pages/useragentstring.php; classtype:attempted-recon; sid:2013028; rev:5; metadata:created_at 2011_06_14, updated_at 2020_04_22;)

Suricata config yaml

%YAML 1.1
---

# Suricata configuration file. In addition to the comments describing all
# options in this file, full documentation can be found at:
# https://suricata.readthedocs.io/en/latest/configuration/suricata-yaml.html

##
## Step 1: inform Suricata about your network
##

vars:
  address-groups:

    HOME_NET: "[10.0.0.0/8,172.16.0.0/12,192.168.0.0/16,224.0.0.0/24]"
    EXTERNAL_NET: "!$HOME_NET"
    HTTP_SERVERS: "$HOME_NET"
    SMTP_SERVERS: "$HOME_NET"
    SQL_SERVERS: "$HOME_NET"
    DNS_SERVERS: "$HOME_NET"
    TELNET_SERVERS: "$HOME_NET"
    AIM_SERVERS: "$EXTERNAL_NET"
    DC_SERVERS: "$HOME_NET"
    DNP3_SERVER: "$HOME_NET"
    DNP3_CLIENT: "$HOME_NET"
    MODBUS_CLIENT: "$HOME_NET"
    MODBUS_SERVER: "$HOME_NET"
    ENIP_CLIENT: "$HOME_NET"
    ENIP_SERVER: "$HOME_NET"

  port-groups:
    HTTP_PORTS: "[80,81,311,383,591,593,901,1220,1414,1741,1830,2301,2381,2809,3037,3128,3702,4343,4848,5250,6988,7000,7001,7144,7145,7510,7777,7779,8000,8008,8014,8028,8080,8085,8088,8090,8118,8123,8180,8181,8243,8280,8300,8800,8888,8899,9000,9060,9080,9090,9091,9443,9999,11371,34443,34444,41080,50002,55555]"
    SHELLCODE_PORTS: "!80"
    ORACLE_PORTS: 1521
    SSH_PORTS: 22
    DNP3_PORTS: 20000
    MODBUS_PORTS: 502
    FILE_DATA_PORTS: "[$HTTP_PORTS,110,143]"
    FTP_PORTS: 21
    VXLAN_PORTS: 4789
    
##
## Step 2: select outputs to enable
##

# The default logging directory.  Any log or output file will be
# placed here if its not specified with a full path name. This can be
# overridden with the -l command line parameter.
default-log-dir: /var/log/suricata/

# global stats configuration
stats:
  enabled: yes
  # The interval field (in seconds) controls at what interval
  # the loggers are invoked.
  interval: 30
  # Add decode events as stats.
  #decoder-events: true
  # Decoder event prefix in stats. Has been 'decoder' before, but that leads
  # to missing events in the eve.stats records. See issue #2225.
  #decoder-events-prefix: "decoder.event"
  # Add stream events as stats.
  #stream-events: false

outputs:
  - fast:
      enabled: no
      filename: fast.log
      append: yes

  - eve-log:
      enabled: yes
      filetype: regular
      filename: eve.json
      # Community Flow ID
      # Adds a 'community_id' field to EVE records. These are meant to give
      # a records a predictable flow id that can be used to match records to
      # output of other tools such as Bro.
      #
      # Takes a 'seed' that needs to be same across sensors and tools
      # to make the id less predictable.

      # enable/disable the community id feature.
      community-id: true
      # Seed value for the ID output. Valid values are 0-65535.
      community-id-seed: 0
      
      # HTTP X-Forwarded-For support by adding an extra field or overwriting
      # the source or destination IP address (depending on flow direction)
      # with the one reported in the X-Forwarded-For HTTP header. This is
      # helpful when reviewing alerts for traffic that is being reverse
      # or forward proxied.
      xff:
        enabled: yes
        # Two operation modes are available, "extra-data" and "overwrite".
        mode: extra-data
        # Two proxy deployments are supported, "reverse" and "forward". In
        # a "reverse" deployment the IP address used is the last one, in a
        # "forward" deployment the first IP address is used.
        deployment: reverse
        # Header name where the actual IP address will be reported, if more
        # than one IP address is present, the last IP address will be the
        # one taken into consideration.
        header: X-Forwarded-For
      types:
        - alert:
            payload: yes           # enable dumping payload in Base64
            packet: yes            # enable dumping of packet (without stream segments)
            http: yes
            payload-printable: yes
            #http-body: yes
            #http-body-printable: yes
        - stats:
            totals: yes       # stats for all threads merged together
            threads: yes       # per thread stats
            deltas: yes        # include delta values

  - unified2-alert:
      enabled: no

  - http-log:
      enabled: no
      filename: http.log
      append: yes

  - tls-log:
      enabled: no  # Log TLS connections.
      filename: tls.log # File to store TLS logs.
      append: yes

  - tls-store:
      enabled: no

  - dns-log:
      enabled: no
      filename: dns.log
      append: yes

  - pcap-log:
      enabled:  no
      filename: pcaps/%t.%n.pcap

      limit: 128mb

      max-files: 8

      mode: multi # normal, multi or sguil.
      use-stream-depth: no
      honor-pass-rules: no

  - alert-debug:
      enabled: no
      filename: alert-debug.log
      append: yes

  - alert-prelude:
      enabled: no
      profile: suricata
      log-packet-content: no
      log-packet-header: yes

  - stats:
      enabled: no
      filename: stats.log
      totals: yes
      threads: no

  - syslog:
      enabled: no
      facility: local5

  - drop:
      enabled: no
      filename: drop.log
      append: yes

  - file-store:
      version: 2
      enabled: no       # set to yes to enable
      log-dir: files    # directory to store the files
      force-magic: yes   # force logging magic on all stored files
      force-md5: no     # force logging of md5 checksums
      force-filestore: no # force storing of all files

  - file-log:
      enabled: no
      filename: files-json.log
      append: yes
      force-magic: yes   # force logging magic on all logged files
      force-md5: no     # force logging of md5 checksums

  - tcp-data:
      enabled: no
      type: file
      filename: tcp-data.log

  - http-body-data:
      enabled: no
      type: file
      filename: http-data.log

  - lua:
      enabled: no
      scripts:
      #   - script1.lua

nflog:
  - group: 2
    buffer-size: 18432
  - group: default
    qthreshold: 1
    qtimeout: 100
    max-size: 20000

af-packet:
  - interface: bond0
    threads: 3
    cluster-id: 1
    # Default AF_PACKET cluster type. AF_PACKET can load balance per flow or per hash.
    # This is only supported for Linux kernel > 3.1
    # possible value are:
    #  * cluster_flow: all packets of a given flow are send to the same socket
    #  * cluster_cpu: all packets treated in kernel by a CPU are send to the same socket
    #  * cluster_qm: all packets linked by network card to a RSS queue are sent to the same
    #  socket. Requires at least Linux 3.14.
    #  * cluster_ebpf: eBPF file load balancing. See doc/userguide/capture-hardware/ebpf-xdp.rst for
    #  more info.
    # Recommended modes are cluster_flow on most boxes and cluster_cpu or cluster_qm on system
    # with capture card using RSS (require cpu affinity tuning and system irq tuning)
    cluster-type: cluster_flow
    defrag: yes # To use the ring feature of AF_PACKET, set 'use-mmap' to yes
    use-mmap: yes
    # Lock memory map to avoid it goes to swap. Be careful that over subscribing could lock
    # your system
    #mmap-locked: yes
    # Use tpacket_v3 capture mode, only active if use-mmap is true
    # Don't use it in IPS or TAP mode as it causes severe latency
    tpacket-v3: yes
    # Ring size will be computed with respect to max_pending_packets and number
    # of threads. You can set manually the ring size in number of packets by setting
    # the following value. If you are using flow cluster-type and have really network
    # intensive single-flow you could want to set the ring-size independently of the number
    # of threads:
    ring-size: 10000
    # Block size is used by tpacket_v3 only. It should set to a value high enough to contain
    # a decent number of packets. Size is in bytes so please consider your MTU. It should be
    # a power of 2 and it must be multiple of page size (usually 4096).
    #block-size: 32768
    # tpacket_v3 block timeout: an open block is passed to userspace if it is not
    # filled after block-timeout milliseconds.
    #block-timeout: 10
    # On busy system, this could help to set it to yes to recover from a packet drop
    # phase. This will result in some packets (at max a ring flush) being non treated.
    #use-emergency-flush: yes
    # recv buffer size, increase value could improve performance
    buffer-size: 65535
    # Set to yes to disable promiscuous mode
    # disable-promisc: no
    # Choose checksum verification mode for the interface. At the moment
    # of the capture, some packets may be with an invalid checksum due to
    # offloading to the network card of the checksum computation.
    # Possible values are:
    #  - kernel: use indication sent by kernel for each packet (default)
    #  - yes: checksum validation is forced
    #  - no: checksum validation is disabled
    #  - auto: suricata uses a statistical approach to detect when
    #  checksum off-loading is used.
    # Warning: 'checksum-validation' must be set to yes to have any validation
    #checksum-checks: kernel
    # BPF filter to apply to this interface. The pcap filter syntax apply here.
    
    # You can use the following variables to activate AF_PACKET tap or IPS mode.
    # If copy-mode is set to ips or tap, the traffic coming to the current
    # interface will be copied to the copy-iface interface. If 'tap' is set, the
    # copy is complete. If 'ips' is set, the packet matching a 'drop' action
    # will not be copied.
    #copy-mode: ips
    #copy-iface: eth1
    #  For eBPF and XDP setup including bypass, filter and load balancing, please
    #  see doc/userguide/capture-hardware/ebpf-xdp.rst for more info.

app-layer:
  protocols:
    krb5:
      enabled: yes
    snmp:
      enabled: yes
    ikev2:
      enabled: yes
    tls:
      enabled: yes
      detection-ports:
        dp: 443

      # Generate JA3 fingerprint from client hello. If not specified it
      # will be disabled by default, but enabled if rules require it.
      #ja3-fingerprints: auto

      # What to do when the encrypted communications start:
      # - default: keep tracking TLS session, check for protocol anomalies,
      #            inspect tls_* keywords. Disables inspection of unmodified
      #            'content' signatures.
      # - bypass:  stop processing this flow as much as possible. No further
      #            TLS parsing and inspection. Offload flow bypass to kernel
      #            or hardware if possible.
      # - full:    keep tracking and inspection as normal. Unmodified content
      #            keyword signatures are inspected as well.
      #
      # For best performance, select 'bypass'.
      #
      #encryption-handling: default

    dcerpc:
      enabled: yes
    ftp:
      enabled: yes
      # memcap: 64mb
    # RDP, disabled by default.
    rdp:
      #enabled: no
    ssh:
      enabled: yes
    smtp:
      enabled: yes
      raw-extraction: no
      # Configure SMTP-MIME Decoder
      mime:
        # Decode MIME messages from SMTP transactions
        # (may be resource intensive)
        # This field supercedes all others because it turns the entire
        # process on or off
        decode-mime: yes

        # Decode MIME entity bodies (ie. base64, quoted-printable, etc.)
        decode-base64: yes
        decode-quoted-printable: yes

        # Maximum bytes per header data value stored in the data structure
        # (default is 2000)
        header-value-depth: 2000

        # Extract URLs and save in state data structure
        extract-urls: yes
        # Set to yes to compute the md5 of the mail body. You will then
        # be able to journalize it.
        body-md5: no
      # Configure inspected-tracker for file_data keyword
      inspected-tracker:
        content-limit: 100000
        content-inspect-min-size: 32768
        content-inspect-window: 4096
    imap:
      enabled: detection-only
    smb:
      enabled: yes
      detection-ports:
        dp: 139, 445

      # Stream reassembly size for SMB streams. By default track it completely.
      #stream-depth: 0

    nfs:
      enabled: yes
    tftp:
      enabled: yes
    dns:
      # memcaps. Globally and per flow/state.
      #global-memcap: 16mb
      #state-memcap: 512kb

      # How many unreplied DNS requests are considered a flood.
      # If the limit is reached, app-layer-event:dns.flooded; will match.
      #request-flood: 500

      tcp:
        enabled: yes
        detection-ports:
          dp: 53
      udp:
        enabled: yes
        detection-ports:
          dp: 53
      http:
        enabled: yes
        # memcap:                   Maximum memory capacity for http
        #                           Default is unlimited, value can be such as 64mb
  
        # default-config:           Used when no server-config matches
        #   personality:            List of personalities used by default
        #   request-body-limit:     Limit reassembly of request body for inspection
        #                           by http_client_body & pcre /P option.
        #   response-body-limit:    Limit reassembly of response body for inspection
        #                           by file_data, http_server_body & pcre /Q option.
        #
        #   For advanced options, see the user guide
  
  
        # server-config:            List of server configurations to use if address matches
        #   address:                List of IP addresses or networks for this block
        #   personalitiy:           List of personalities used by this block
        #
        #                           Then, all the fields from default-config can be overloaded
        #
        # Currently Available Personalities:
        #   Minimal, Generic, IDS (default), IIS_4_0, IIS_5_0, IIS_5_1, IIS_6_0,
        #   IIS_7_0, IIS_7_5, Apache_2
      libhtp:
         default-config:
           personality: IDS

           # Can be specified in kb, mb, gb.  Just a number indicates
           # it's in bytes.
           request-body-limit: 100kb
           response-body-limit: 100kb

           # inspection limits
           request-body-minimal-inspect-size: 32kb
           request-body-inspect-window: 4kb
           response-body-minimal-inspect-size: 40kb
           response-body-inspect-window: 16kb

           # response body decompression (0 disables)
           response-body-decompress-layer-limit: 2

           # auto will use http-body-inline mode in IPS mode, yes or no set it statically
           http-body-inline: auto

           # Decompress SWF files.
           # 2 types: 'deflate', 'lzma', 'both' will decompress deflate and lzma
           # compress-depth:
           # Specifies the maximum amount of data to decompress,
           # set 0 for unlimited.
           # decompress-depth:
           # Specifies the maximum amount of decompressed data to obtain,
           # set 0 for unlimited.
           swf-decompression:
             enabled: yes
             type: both
             compress-depth: 0
             decompress-depth: 0

           # Take a random value for inspection sizes around the specified value.
           # This lower the risk of some evasion technics but could lead
           # detection change between runs. It is set to 'yes' by default.
           #randomize-inspection-sizes: yes
           # If randomize-inspection-sizes is active, the value of various
           # inspection size will be choosen in the [1 - range%, 1 + range%]
           # range
           # Default value of randomize-inspection-range is 10.
           #randomize-inspection-range: 10

           # decoding
           double-decode-path: no
           double-decode-query: no

           # Can disable LZMA decompression
           #lzma-enabled: yes
           # Memory limit usage for LZMA decompression dictionary
           # Data is decompressed until dictionary reaches this size
           #lzma-memlimit: 1mb
           # Maximum decompressed size with a compression ratio
           # above 2048 (only LZMA can reach this ratio, deflate cannot)
           #compression-bomb-limit: 1mb

         server-config:

           #- apache:
           #    address: [192.168.1.0/24, 127.0.0.0/8, "::1"]
           #    personality: Apache_2
           #    # Can be specified in kb, mb, gb.  Just a number indicates
           #    # it's in bytes.
           #    request-body-limit: 4096
           #    response-body-limit: 4096
           #    double-decode-path: no
           #    double-decode-query: no

           #- iis7:
           #    address:
           #      - 192.168.0.0/24
           #      - 192.168.10.0/24
           #    personality: IIS_7_0
           #    # Can be specified in kb, mb, gb.  Just a number indicates
           #    # it's in bytes.
           #    request-body-limit: 4096
           #    response-body-limit: 4096
           #    double-decode-path: no
           #    double-decode-query: no

    # Note: Modbus probe parser is minimalist due to the poor significant field
    # Only Modbus message length (greater than Modbus header length)
    # And Protocol ID (equal to 0) are checked in probing parser
    # It is important to enable detection port and define Modbus port
    # to avoid false positive
    modbus:
      # How many unreplied Modbus requests are considered a flood.
      # If the limit is reached, app-layer-event:modbus.flooded; will match.
      #request-flood: 500

      enabled: no
      detection-ports:
        dp: 502
      # According to MODBUS Messaging on TCP/IP Implementation Guide V1.0b, it
      # is recommended to keep the TCP connection opened with a remote device
      # and not to open and close it for each MODBUS/TCP transaction. In that
      # case, it is important to set the depth of the stream reassembling as
      # unlimited (stream.reassembly.depth: 0)

      # Stream reassembly size for modbus. By default track it completely.
      stream-depth: 0

    # DNP3
    dnp3:
      enabled: no
      detection-ports:
        dp: 20000

    # SCADA EtherNet/IP and CIP protocol support
    enip:
      enabled: no
      detection-ports:
        dp: 44818
        sp: 44818

    ntp:
      enabled: yes

    dhcp:
      enabled: yes

    # SIP, disabled by default.
    sip:
      #enabled: no

##############################################################################
##
## Advanced settings below
##
##############################################################################

##
## Run Options
##

# Run suricata as user and group.
#run-as:
#  user: suri
#  group: suri

# Some logging module will use that name in event as identifier. The default
# value is the hostname
#sensor-name: suricata

# Default location of the pid file. The pid file is only used in
# daemon mode (start Suricata with -D). If not running in daemon mode
# the --pidfile command line option must be used to create a pid file.
#pid-file: /var/run/suricata.pid

# Daemon working directory
# Suricata will change directory to this one if provided
# Default: "/"
#daemon-directory: "/"

# Umask.
# Suricata will use this umask if it is provided. By default it will use the
# umask passed on by the shell.
#umask: 022

# Suricata core dump configuration. Limits the size of the core dump file to
# approximately max-dump. The actual core dump size will be a multiple of the
# page size. Core dumps that would be larger than max-dump are truncated. On
# Linux, the actual core dump size may be a few pages larger than max-dump.
# Setting max-dump to 0 disables core dumping.
# Setting max-dump to 'unlimited' will give the full core dump file.
# On 32-bit Linux, a max-dump value >= ULONG_MAX may cause the core dump size
# to be 'unlimited'.

coredump:
  max-dump: unlimited

# If Suricata box is a router for the sniffed networks, set it to 'router'. If
# it is a pure sniffing setup, set it to 'sniffer-only'.
# If set to auto, the variable is internally switch to 'router' in IPS mode
# and 'sniffer-only' in IDS mode.
# This feature is currently only used by the reject* keywords.
host-mode: auto

# Number of packets preallocated per thread. The default is 1024. A higher number 
# will make sure each CPU will be more easily kept busy, but may negatively 
# impact caching.
#max-pending-packets: 1024

# Runmode the engine should use. Please check --list-runmodes to get the available
# runmodes for each packet acquisition method. Default depends on selected capture
# method. 'workers' generally gives best performance.
runmode: workers

# Specifies the kind of flow load balancer used by the flow pinned autofp mode.
#
# Supported schedulers are:
#
# hash     - Flow assigned to threads using the 5-7 tuple hash.
# ippair   - Flow assigned to threads using addresses only.
#
#autofp-scheduler: hash

# Preallocated size for packet. Default is 1514 which is the classical
# size for pcap on ethernet. You should adjust this value to the highest
# packet size (MTU + hardware header) on your system.
#default-packet-size: 1514

# Unix command socket can be used to pass commands to Suricata.
# An external tool can then connect to get information from Suricata
# or trigger some modifications of the engine. Set enabled to yes
# to activate the feature. In auto mode, the feature will only be
# activated in live capture mode. You can use the filename variable to set
# the file name of the socket.
unix-command:
  enabled: yes
  #filename: custom.socket

# Magic file. The extension .mgc is added to the value here.
#magic-file: /usr/share/file/magic
#magic-file: 

# GeoIP2 database file. Specify path and filename of GeoIP2 database
# if using rules with "geoip" rule option.
#geoip-database: /usr/local/share/GeoLite2/GeoLite2-Country.mmdb

legacy:
  uricontent: enabled


threshold-file: /etc/suricata/threshold.config

detect-engine:
  - profile: high
  - custom-values:
      toclient-src-groups: 2
      toclient-dst-groups: 2
      toclient-sp-groups: 2
      toclient-dp-groups: 3
      toserver-src-groups: 2
      toserver-dst-groups: 4
      toserver-sp-groups: 2
      toserver-dp-groups: 25
  - sgh-mpm-context: auto
  - inspection-recursion-limit: 3000

threading:
  set-cpu-affinity: no
  cpu-affinity:
    - management-cpu-set:
        cpu: [ 0 ]
    - receive-cpu-set:
        cpu: [ 0 ]
    - decode-cpu-set:
        cpu: [ 0, 1 ]
        mode: "balanced"
    - stream-cpu-set:
        cpu: [ "0-1" ]
    - detect-cpu-set:
        cpu: [ "all" ]
        mode: "exclusive"
        prio:
          low: [ 0 ]
          medium: [ "1-2" ]
          high: [ 3 ]
          default: "medium"
    - verdict-cpu-set:
        cpu: [ 0 ]
        prio:
          default: "high"
    - reject-cpu-set:
        cpu: [ 0 ]
        prio:
          default: "low"
    - output-cpu-set:
        cpu: [ "all" ]
        prio:
           default: "medium"

  detect-thread-ratio: 1.5



mpm-algo: ac-ks
# Defrag settings:

defrag:
  memcap: 32mb
  hash-size: 65536
  trackers: 65535 # number of defragmented flows to follow
  max-frags: 65535 # number of fragments to keep (higher than trackers)
  prealloc: yes
  timeout: 60


flow:
  memcap: 128mb
  hash-size: 65536
  prealloc: 10000
  emergency-recovery: 30
  #managers: 1 # default to one flow manager
  #recyclers: 1 # default to one flow recycler thread

# This option controls the use of vlan ids in the flow (and defrag)
# hashing. Normally this should be enabled, but in some (broken)
# setups where both sides of a flow are not tagged with the same vlan
# tag, we can ignore the vlan id's in the flow hashing.
vlan:
  use-for-tracking: true

# Specific timeouts for flows. Here you can specify the timeouts that the
# active flows will wait to transit from the current state to another, on each
# protocol. The value of "new" determine the seconds to wait after a handshake or
# stream startup before the engine free the data of that flow it doesn't
# change the state to established (usually if we don't receive more packets
# of that flow). The value of "established" is the amount of
# seconds that the engine will wait to free the flow if it spend that amount
# without receiving new packets or closing the connection. "closed" is the
# amount of time to wait after a flow is closed (usually zero). "bypassed"
# timeout controls locally bypassed flows. For these flows we don't do any other
# tracking. If no packets have been seen after this timeout, the flow is discarded.
#
# There's an emergency mode that will become active under attack circumstances,
# making the engine to check flow status faster. This configuration variables
# use the prefix "emergency-" and work similar as the normal ones.
# Some timeouts doesn't apply to all the protocols, like "closed", for udp and
# icmp.

flow-timeouts:

  default:
    new: 30
    established: 300
    closed: 0
    bypassed: 100
    emergency-new: 10
    emergency-established: 100
    emergency-closed: 0
    emergency-bypassed: 50
  tcp:
    new: 60
    established: 600
    closed: 60
    bypassed: 100
    emergency-new: 5
    emergency-established: 100
    emergency-closed: 10
    emergency-bypassed: 50
  udp:
    new: 30
    established: 300
    bypassed: 100
    emergency-new: 10
    emergency-established: 100
    emergency-bypassed: 50
  icmp:
    new: 30
    established: 300
    bypassed: 100
    emergency-new: 10
    emergency-established: 100
    emergency-bypassed: 50

stream:
  memcap: 64mb
  checksum-validation: no       # do not reject wrong csums
  inline: auto                  # auto will use inline mode in IPS mode, yes or no set it statically
  reassembly:
    memcap: 256mb
    depth: 1mb                  # reassemble 1mb into a stream
    toserver-chunk-size: 2560
    toclient-chunk-size: 2560
    randomize-chunk-size: yes

host:
  hash-size: 4096
  prealloc: 1000
  memcap: 32mb

logging:
  default-log-level: notice
  default-output-filter:

  outputs:
  - console:
      enabled: no
  - file:
      enabled: yes
      filename: /var/log/suricata/suricata.log
  - syslog:
      enabled: no
      facility: local5

pfring:

pcap:

pcap-file:
  checksum-checks: auto

ipfw:

default-rule-path: /etc/suricata/rules
rule-files:
 - et.rules

classification-file: /etc/suricata/classification.config
reference-config-file: /etc/suricata/reference.config

host-os-policy:
  windows: [0.0.0.0/0]
  bsd: []
  bsd-right: []
  old-linux: []
  linux: []
  old-solaris: []
  solaris: []
  hpux10: []
  hpux11: []
  irix: []
  macos: []
  vista: []
  windows2k3: []

asn1-max-frames: 256

engine-analysis:
  rules-fast-pattern: yes
  rules: yes

pcre:
  match-limit: 3500
  match-limit-recursion: 1500

profiling:
  sample-rate: 1000

  rules:

    enabled: yes
    filename: rule_perf.log
    append: yes
    sort: avgticks
    limit: 100
    json: true

  keywords:
    enabled: yes
    filename: keyword_perf.log
    append: yes

  packets:
    enabled: yes
    filename: packet_stats.log
    append: yes

    csv:
      enabled: no
      filename: packet_stats.csv

  locks:
    enabled: no
    filename: lock_stats.log
    append: yes

  pcap-log:
    enabled: no
    filename: pcaplog_stats.log
    append: yes

coredump:
  max-dump: unlimited

# Includes.  Files included here will be handled as if they were
# inlined in this configuration file.
#include: include1.yaml
#include: include2.yaml

test_my_nids.pcap (1.6 KB)

Can you also share the full stats.log?

Which verison are you running?