VPP SNMP AgentX Bridge

A Go application that bridges VPP (Vector Packet Processing) interface statistics to SNMP using the AgentX protocol. It queries VPP interface counters and exposes them via the standard IF-MIB (1.3.6.1.2.1.31.1.1.1) for SNMP monitoring.

Features

• Real-time VPP interface statistics via SNMP
• Standard IF-MIB compliance (ifXTable)
• AgentX protocol support (TCP and Unix sockets)
• Configurable interface index offset to avoid conflicts
• Configurable polling intervals
• Thread-safe operation with proper synchronization

Architecture

VPP Stats Socket → VPP Stats Client → Interface MIB → AgentX → SNMP Master Agent

The application consists of three main components:

1. VPP Stats Client (vppstats/): Connects to VPP stats socket and retrieves interface counters
2. Interface MIB (ifmib/): Maps VPP statistics to SNMP IF-MIB structure
3. AgentX Client: Registers with SNMP master agent to serve the MIB data

Build Instructions

Development Build

go build -o vpp-snmp-agent .

Static Binary Build

For deployment without Go runtime dependencies:

# Linux static binary
CGO_ENABLED=0 GOOS=linux go build -a -ldflags '-extldflags "-static"' -o vpp-snmp-agent .

# Cross-compile for different architectures
CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build -a -ldflags '-extldflags "-static"' -o vpp-snmp-agent-linux-amd64 .
CGO_ENABLED=0 GOOS=linux GOARCH=arm64 go build -a -ldflags '-extldflags "-static"' -o vpp-snmp-agent-linux-arm64 .

Release Build with Version Info

VERSION=$(git describe --tags --always --dirty)
BUILD_TIME=$(date -u '+%Y-%m-%d_%H:%M:%S')
CGO_ENABLED=0 go build -ldflags "-X main.version=${VERSION} -X main.buildTime=${BUILD_TIME}" -o vpp-snmp-agent .

Usage

Basic Usage

# Run with default settings
./vpp-snmp-agent

# Run with custom AgentX address
./vpp-snmp-agent -agentx-addr 127.0.0.1:705

# Run with Unix socket AgentX connection
./vpp-snmp-agent -agentx-addr /var/agentx/master

Command Line Flags

Flag	Default	Description
-agentx-addr	localhost:705	AgentX master agent address (hostname:port or Unix socket path)
-vpp-stats-addr	/var/run/vpp/stats.sock	VPP statistics socket path
-period	10.0	Interval in seconds for querying VPP interface stats
-vpp-ifindex-offset	1000	Offset to add to VPP interface indices for SNMP

Examples

# Custom polling interval (5 seconds)
./vpp-snmp-agent -period 5.0

# Custom VPP stats socket
./vpp-snmp-agent -vpp-stats-addr /custom/path/stats.sock

# Custom interface index offset (start at 2000)
./vpp-snmp-agent -vpp-ifindex-offset 2000

# Full configuration
./vpp-snmp-agent \
  -agentx-addr /var/agentx/master \
  -vpp-stats-addr /var/run/vpp/stats.sock \
  -period 5.0 \
  -vpp-ifindex-offset 1000

SNMP Interface Mapping

VPP interfaces are mapped to SNMP indices with a configurable offset (default 1000):

• VPP Interface 0 → SNMP Index 1000
• VPP Interface 1 → SNMP Index 1001
• VPP Interface N → SNMP Index (N + offset)

Supported MIB Objects

The application implements the ifXTable (1.3.6.1.2.1.31.1.1.1) with the following objects:

OID	Object	Type	Description
.1.{index}	ifName	DisplayString	Interface name
.2.{index}	ifInMulticastPkts	Counter32	RX multicast packets
.3.{index}	ifInBroadcastPkts	Counter32	RX broadcast packets
.4.{index}	ifOutMulticastPkts	Counter32	TX multicast packets
.5.{index}	ifOutBroadcastPkts	Counter32	TX broadcast packets
.6.{index}	ifHCInOctets	Counter64	RX bytes (high capacity)
.7.{index}	ifHCInUcastPkts	Counter64	RX unicast packets (high capacity)
.8.{index}	ifHCInMulticastPkts	Counter64	RX multicast packets (high capacity)
.9.{index}	ifHCInBroadcastPkts	Counter64	RX broadcast packets (high capacity)
.10.{index}	ifHCOutOctets	Counter64	TX bytes (high capacity)
.11.{index}	ifHCOutUcastPkts	Counter64	TX unicast packets (high capacity)
.12.{index}	ifHCOutMulticastPkts	Counter64	TX multicast packets (high capacity)
.13.{index}	ifHCOutBroadcastPkts	Counter64	TX broadcast packets (high capacity)

SNMP Query Examples

Query Interface Names

# Get all interface names
snmpwalk -v2c -c public localhost 1.3.6.1.2.1.31.1.1.1.1

# Get specific interface name (interface 0 with default offset)
snmpget -v2c -c public localhost 1.3.6.1.2.1.31.1.1.1.1.1000

Query Interface Counters

# Get RX bytes for interface 0
snmpget -v2c -c public localhost 1.3.6.1.2.1.31.1.1.1.6.1000

# Get TX bytes for interface 1
snmpget -v2c -c public localhost 1.3.6.1.2.1.31.1.1.1.10.1001

# Walk all interface counters
snmpwalk -v2c -c public localhost 1.3.6.1.2.1.31.1.1.1

Query with Custom Offset

If running with -vpp-ifindex-offset 2000:

# Interface 0 counters at index 2000
snmpget -v2c -c public localhost 1.3.6.1.2.1.31.1.1.1.6.2000

Prerequisites

VPP Requirements

• VPP must be running with stats socket enabled
• Stats socket accessible at /var/run/vpp/stats.sock (or custom path)
• Application must have read permissions on the stats socket

SNMP Requirements

• SNMP master agent running (net-snmp's snmpd)
• AgentX protocol enabled in snmpd configuration
• AgentX socket accessible (TCP port 705 or Unix socket)

SNMP Agent Configuration

Add to /etc/snmp/snmpd.conf:

# Enable AgentX
master agentx
agentXSocket tcp:localhost:705
# or for Unix socket:
# agentXSocket /var/agentx/master

Troubleshooting

Common Issues

1. "Failed to connect to VPP stats"

   • Check VPP is running: vppctl show version
   • Verify stats socket exists: ls -la /var/run/vpp/stats.sock
   • Check permissions on stats socket

2. "Failed to dial AgentX"

   • Verify SNMP agent is running: systemctl status snmpd
   • Check AgentX is enabled in snmpd.conf
   • Test AgentX socket: netstat -ln | grep 705

3. "Failed to register IF-MIB: ErrorDuplicateRegistration"

   • Another agent is already serving the IF-MIB
   • Check with: snmpwalk -v2c -c public localhost 1.3.6.1.2.1.31.1.1.1

4. "Retrieved stats for 0 interfaces"

   • VPP may have no interfaces configured
   • Check VPP interfaces: vppctl show interface

Debug Commands

# Check VPP interfaces
vppctl show interface

# Check VPP stats
vppctl show stats

# Test SNMP master agent
snmpwalk -v2c -c public localhost 1.3.6.1.2.1.1

# Check AgentX registration
snmpwalk -v2c -c public localhost 1.3.6.1.2.1.31.1.1.1

License

This project uses the LGPL 3.0 licensed go-agentx library.

Contributing

1. Fork the repository
2. Create a feature branch
3. Make your changes
4. Add tests if applicable
5. Submit a pull request

Version History

• v1.0.0: Initial release with IF-MIB support
• v1.1.0: Added configurable interface index offset
• v1.2.0: Added Unix socket support for AgentX