Prometheus reports: "Error scraping target: server returned HTTP status 404 Not Found"

[diegomsamana]

Hi, everyone. I'm trying to create the configurations necessary to use prometheus and snmp exporter against a Citrix NetScaler device. I created a generator.yml, and used it to create my snmp.yml (I am attaching them to this post.

After that, I configured prometheus.yml as it is presented in the end of this post. When I start the different components, I see the error in the title in the prometheus "targets" section. I have enabled debug log and snmp trace log in my snmp explorer config (but do not see anything relevant - side questions... where are this logs located when using docker?):

snmp_exporter: image: prom/snmp-exporter:latest ports: - "9116:9116" volumes: - ./config/snmp/snmp.yml:/etc/snmp/snmp.yml command: --config.file=/etc/snmp/snmp.yml --web.listen-address=:9116 --web.telemetry-path=/metrics --snmp.debug-packets --log.level=debug restart: unless-stopped

But I do not see any output that refers to an error. This is my first time testing with the SNMP exporter, and I'm a little at a loss here. As additional context, I added the output of the snmpbulkwalk that I have obtained after running it successfully agains my NetScaler device.

diedo@testserver:~/Documents/github/samm-syslogsnmp$ docker compose logs --tail 50 --follow snmp_exporter
snmp_exporter-1 | time=2025-07-15T17:40:53.284Z level=INFO source=main.go:211 msg="Starting snmp_exporter" version="(version=0.29.0, branch=HEAD, revision=42f8f2a991516b39ed60ef67eb69263d817ecd52)" concurrency=0xc0000113e0 debug_snmp=0xc0000113e8
snmp_exporter-1 | time=2025-07-15T17:40:53.284Z level=INFO source=main.go:212 msg="operational information" build_context="(go=go1.24.1, platform=linux/amd64, user=root@eb19c64890c6, date=20250423-05:51:05, tags=unknown)"
snmp_exporter-1 | time=2025-07-15T17:40:53.318Z level=INFO source=tls_config.go:347 msg="Listening on" address=[::]:9116
snmp_exporter-1 | time=2025-07-15T17:40:53.318Z level=INFO source=tls_config.go:350 msg="TLS is disabled." http2=false address=[::]:9116

`

Scrape configurations

scrape_configs:

• job_name: 'prometheus'
  scrape_interval: 30s
  static_configs:
  • targets: ['localhost:9090']
• job_name: 'snmp_netscaler'
  scrape_interval: 600s
  scrape_timeout: 595s
  static_configs:
  • targets: ['udp://192.168.86.247:161'] # SNMP NetScaler device using UDP transport and custom port.
    labels:
    job: 'netscaler'
    metrics_path: /snmp_netscaler
    params:
    auth: [public_v2]
    module:
    • system
    • if_mib
    • ip_mib
    • ucd_la_table
    • ucd_memory
    • ucd_system_stats
    • keepalived
    • hrSystem
    • hrStorage
    • hrDevice
    • hrSWRun
    • hrSWRunPerf
    • hrSWInstalled
    • nssystem
    • nssysifTable
    • nsifstatistics
    • nspolbasedroutingstats
    • nsvservers
    • nsvservers_svcs
    • nsSslStatsGroup
    • nsCompressionStatsGroup
    • nsCacheStatsGroup
    • nsvserverCspolicyTable
    • nsvserverGlobalStatsGroup
    • nslbvserverTable
    • nsgslbGlobalStats
    • nsAaaStatsGroup
    • nsSslVpnStatsGroup
    • nsappFirewallStatistics
    • nsSysGroup
    • nsResourceGroup
      relabel_configs:
    • source_labels: [address]
      target_label: __param_target
    • source_labels: [__param_target]
      target_label: instance
    • target_label: address
      replacement: snmp_exporter:9116 # The SNMP exporter's real hostname:port.

Global exporter-level metrics

• job_name: 'snmp_exporter'
  static_configs:
  • targets: ['snmp_exporter:9116']`

generator-ns.yml.txt
snmp.ym.txt
snmpbulkwalk.txt

[diegomsamana]

NVM... I had an erroneous configuration