Follow below attached flow chart or steps to troubleshoot NIC issues.

1. Start NIC Troubleshooting

2. Physical Layer Check

2.1. Check if interface is up
       → If not up, continue to next step

2.2. Is SFP present?

• Yes → Check SFP diagnostics

• No → Back-to-back test between VOS interfaces

2.3. Does back-to-back test succeed?

• No → Change network cable

• Yes →
  - Check configuration on peer device
  - Insert SFP and cable firmly
     - Reboot VOS

2.4. Is interface up now?

• No → Continue troubleshooting physical layer issues

• Yes → Proceed to next stage

3. Network Layer Check

3.1. Ping next hop
       → Is ARP resolved?

• Yes → Problem Resolved

• No → Run tcpdump on VOS

3.2. Are ARP requests and responses seen?

• Yes → Is peer device responding?
    - Yes → Are packets received by peer or responses not reaching VOS?
      - Yes → Look at VOS packet drop counts or enable packet trace

• No → Is VOS sending ARP or ICMP packets?
    - No → Check IP address configuration
    - Yes → Check on peer device

4. VOS Bypass Test (if needed)

4.1. Stop VOS services
4.2. Enable same IP in native Linux
4.3. Ping next hop from native Linux

→ Does ping work on native Linux?

• Yes → Reach out to Versa Support

• No → Check on peer device or contact device vendor

✅ Problem Resolved

Versa recommends using Versa qualified SFPs - https://support.versa-networks.com/support_home?id=kb_article_view&sys_kb_id=c0c0e43487028b10389dedf50cbb3513

Please refer this article for ARP issues - https://support.versa-networks.com/support_home?id=kb_article_view&sys_kb_id=1100a0bc87ce4b10389dedf50cbb352b