SimpArp: A Beginner’s Guide to Simplified ARP Management

Troubleshooting ARP Issues with SimpArp — Tips & Tricks

Quick checklist

• Confirm scope: Verify SimpArp is handling ARP (MIDI plugin vs. network tool). I’ll assume you mean a network ARP helper named “SimpArp.”
• Symptoms to observe: high ARP traffic, incorrect MAC mappings, intermittent connectivity, ARP table flapping, suspected ARP spoofing.

Diagnostic steps (ordered)

1. Capture ARP traffic
   • Run a packet capture on the affected segment (tcpdump or Wireshark filter: arp).
   • Save captures for analysis (look for duplicate IPs, gratuitous ARP floods, unexpected ARP replies).
2. Inspect ARP cache
   • On hosts/routers check ARP table (arp -a or ip neigh show) to spot wrong or changing MACs.
3. Verify SimpArp configuration
   • Check mode (proxy, relay, static mappings), interface bindings, and any rate limits or caching timeouts.
4. Compare timings
   • Correlate ARP packet timestamps with outage events to find causation.
5. Look for gratuitous ARPs
   • Legitimate gratuitous ARPs indicate IP movement; many gratuitous ARPs can mean misconfiguration/looping.
6. Check for loops or duplicate IPs
   • Use ARP and DHCP logs to find the same IP advertised by multiple MACs or devices.
7. Test with static entries
   • Temporarily add static ARP entries for critical endpoints to validate whether dynamic resolution is the issue.
8. Rate-limit and filtering
   • If ARP storms appear, enable ARP rate-limiting or ACLs on switches/routers and on SimpArp if supported.
9. Detect spoofing
   • Compare MAC vendor OUI against expected device types; use ARP watch tools (arpwatch/ArpON) or switch port-security.
10. Restart and isolate