MMT-Probe Operation
Guide the user through running MMT-Probe, interpreting its output, and controlling it at runtime.
Triggers
Use this skill when the user asks to:
- •Run or start MMT-Probe
- •Analyze a PCAP file
- •Understand report output or data format
- •Check probe status or logs
- •Control the probe at runtime (start, stop, update)
- •Troubleshoot operational issues (no output, packet drops, etc.)
Important: Docker / Non-root Environments
Inside Docker containers you typically run as root, so sudo is not needed and may not be available. Omit sudo from all commands when running inside Docker. The commands below show sudo for host use; drop it in containers. Note also that systemctl is typically unavailable inside containers.
Execution Modes
Live capture on interface
bash
sudo ./probe -i eth0 # on host (needs root for raw capture) ./probe -i eth0 # in Docker (already root)
Offline PCAP analysis
bash
./probe -t /path/to/capture.pcap # no sudo needed for file analysis
With a configuration file
bash
./probe -c /path/to/mmt-probe.conf
As a systemd service
Available when installed to /opt/mmt/probe/ on a host with systemd (not available inside Docker).
bash
sudo systemctl start mmt-probe sudo systemctl stop mmt-probe sudo systemctl status mmt-probe
With Docker
bash
# Live capture
docker run --network=host ghcr.io/montimage/mmt-probe:latest \
mmt-probe -i eth0 -Xfile-output.enable=true
# PCAP file analysis
docker run -v /path/to/pcaps:/data ghcr.io/montimage/mmt-probe:latest \
mmt-probe -t /data/capture.pcap
Quick test
bash
./probe -t test/UA-Exp01.pcap -Xfile-output.output-dir=/tmp/mmt-test/ ls -la /tmp/mmt-test/
CLI Flags Reference
| Flag | Description | Example |
|---|---|---|
-v | Print version info and exit | ./probe -v |
-h | Print usage help and exit | ./probe -h |
-c <file> | Use specific config file | ./probe -c my.conf |
-t <pcap> | Offline mode: analyze PCAP file | ./probe -t capture.pcap |
-i <iface> | Online mode: capture on interface | ./probe -i eth0 |
-X <key>=<val> | Override a config parameter | -Xthread-nb=4 |
-x | List all overridable parameters | ./probe -x |
Multiple -X flags can be combined:
bash
./probe -i eth0 -Xfile-output.enable=true -Xsecurity.enable=true -Xthread-nb=2
Use
sudoon a host system for live capture. In Docker, omit it.
Report Types
All reports share a common header:
| Column | Name | Description |
|---|---|---|
| 1 | format_id | Report type identifier |
| 2 | probe_id | Probe instance identifier |
| 3 | source | Interface name or PCAP file path |
| 4 | timestamp | Seconds.micros (packet time or real time for id=201) |
Report Type Summary
| Format ID | Name | Description | Channel |
|---|---|---|---|
| 1 | Startup | Sent once at probe start (version info) | — |
| 10 | Security | Security alerts from MMT-Security | security.report |
| 30 | License | License status reports | license.stat |
| 99 | Protocol Stats | Protocol/app statistics (non-session) | — |
| 100 | Session | Per-flow session statistics | session.report |
| 200 | Status | Probe liveness + packet counts (online only) | — |
| 201 | System Info | CPU and memory usage of the host | — |
| 301 | HTTP Reconstruct | Metadata of reconstructed HTTP files | — |
| 400 | eNodeB Topology | LTE element add/remove events | — |
| 401 | eNodeB QoS | UE dedicated bearer allocation | — |
| 1000 | Event | Custom event-triggered reports | event.report |
Status Report (ID 200)
Reports probe liveness during live capture. Created every stats-period seconds.
| Col | Name | Description |
|---|---|---|
| 5 | nic-pkt | Packets received by NIC |
| 6 | nic-lost | Packets dropped by NIC |
| 7 | mmt-pkt | Packets received by MMT |
| 8 | mmt-lost | Packets dropped by MMT |
| 9 | mmt-bytes | Bytes received by MMT |
| 10 | mmt-b-lost | Bytes dropped by MMT |
System Info Report (ID 201)
| Col | Name | Description |
|---|---|---|
| 5 | user_cpu | % CPU in user mode |
| 6 | sys_cpu | % CPU in system mode |
| 7 | idle | % CPU idle |
| 8 | avail_mem | Available memory (kB) |
| 9 | total_mem | Total memory (kB) |
Example: 201,3,"eth0",1498126191.034157,98.57,0.72,0.72,1597680,2048184
Session Report (ID 100)
Per-flow statistics with 41 common columns including:
- •Client/server IP and MAC addresses (cols 20-23)
- •Session ID, ports (cols 24-26)
- •Handshake time, app response time, data transfer time (cols 28-30)
- •Client/server RTT min/max/avg (cols 31-36)
- •TCP retransmissions (cols 37-38)
- •Sub-format ID (col 39) determining extension fields
Session sub-formats
| Sub-format | Protocol | Extension Fields |
|---|---|---|
| 0 | Default | (none) |
| 1 | HTTP | Response time, hostname, MIME, referrer, CDN, URI, method, status |
| 2 | SSL | Server name, CDN flag |
| 3 | RTP | Packet loss rate, burstiness, max jitter, order errors |
| 4 | FTP | Username, password, file size, file name, direction |
| 5 | GTP | Outer IP src/dst, TEIDs array |
Event Report (ID 1000)
| Col | Name | Description |
|---|---|---|
| 5 | event-id | String identifier of the event-report |
| 6 | event | Event attribute value that triggered the report |
| 7+ | attributes | Registered attributes (variable count) |
Example: 1000,3,"./file.pcap",1399407481.189781,1,172.19.190.67,172.19.190.67
Security Report (ID 10)
| Col | Name | Description |
|---|---|---|
| 5 | property_id | Rule identifier number |
| 6 | verdict | detected, not_detected, respected, not_respected, unknown |
| 7 | type | attack, security, test, evasion |
| 8 | cause | Description of the property |
| 9 | history | JSON object with events leading to the verdict |
Output Channel Quick Reference
Reports can be directed to specific output channels using output-channel:
code
output-channel = {file} # File only
output-channel = {redis, kafka} # Redis and Kafka
output-channel = {file, mongodb, socket, mqtt} # Multiple
output-channel = {stdout} # Console output
output-channel = {} # Default (file)
Each channel must be globally enabled (e.g., kafka-output.enable = true) for the routing to work.
Dynamic Control
Requires: DYNAMIC_CONFIG_MODULE and dynamic-config.enable = true
Control the probe at runtime via Unix domain socket (default: /tmp/mmt.sock).
Start processing
bash
printf "start\0" | nc -U /tmp/mmt.sock # in Docker (already root) printf "start\0" | sudo nc -U /tmp/mmt.sock # on host
Returns: 0=success, 1=already running, 2=error
Stop processing
bash
printf "stop\0" | nc -U /tmp/mmt.sock
Returns: 0=success, 1=not running, 2=error
Update configuration
bash
printf 'update{\ninput.source="enp0s3"\ninput.mode=ONLINE\n}\0' | nc -U /tmp/mmt.sock
Returns: 0=updated (no restart), 1=updated (restarted), 2=syntax error, 3=internal error
List parameters
bash
printf 'ls\0' | nc -U /tmp/mmt.sock
Viewing Logs
bash
# Systemd service logs journalctl -t mmt-probe # Follow logs in real time journalctl -t mmt-probe -f # Logs from last hour journalctl -t mmt-probe --since "1 hour ago"
Performance Tips
- •Increase threads for high-throughput:
-Xthread-nb=4 - •Increase queue size to reduce drops:
-Xthread-queue=524288 - •Use BPF filters to reduce processing load:
-Xinput.pcap-filter="tcp port 80" - •Increase cache for batch efficiency:
-Xoutput.cache-max=500000 - •Disable unused reports to reduce overhead:
- •
-Xsession-report.http=false -Xsession-report.rtp=false
- •
- •Use DPDK for 10Gbps+ links (requires DPDK build)
Troubleshooting Operations
| Problem | Possible Cause | Solution |
|---|---|---|
| No output files | file-output.enable is false | -Xfile-output.enable=true |
| No output files | Wrong output directory | Check -Xfile-output.output-dir path exists |
| Probe exits immediately | License check failed | Remove LICENSE_MODULE or provide license.key |
High nic-lost in status reports | NIC buffer too small | Increase input.buffer-size |
High mmt-lost in status reports | Processing too slow | Increase thread-nb and thread-queue |
| Packet drops with multi-thread | Thread queue full | Increase thread-queue value |
Permission denied on interface | Missing root/capabilities | Run with sudo on host, or use --network=host in Docker |
error while loading shared libraries | Library path issue | Run ldconfig (or sudo ldconfig on host) |
sudo: command not found | Running inside Docker | Omit sudo — you are already root in Docker |
| High memory usage | Too many active sessions | Reduce session-timeout values |
| Reports not in expected channel | Channel not enabled | Ensure global <channel>-output.enable = true |
Cross-references
- •To install MMT-Probe, use
/mmt-install. - •To configure the probe, use
/mmt-configure. - •For general help and architecture, use
/mmt-help.