Packet Drop Issues

Please Verify the Following Configuration:

• PATHMTU, MSSFIX
• Packet Fragmentation
• Link Flapping
• DDoS
• Firewall (DPI)
• Filtering
• IPS/IDS
• QoS Configuration
• Routing Issues

DDoS

• Verify if DDoS protection is enabled on the WAN interface.
• Check if incoming packets have source IPs flagged as spoofed addresses.
• Determine if the IP is flagged for an attack or port scan:
  • IPs flagged as part of an attack are blocked for 5 minutes.
  • IPs flagged as part of a port scan are blocked for 1 day.
  • If the IP is mistakenly blocked, add it to the Allowlist or adjust the DDoS threshold limits.

Firewall

• Check the Firewall → SDWAN_FORWARD chain for any rules that might be dropping packets.

Filtering

• Verify if the IP subnet is listed under the IP Block List.
• Check if the MAC address is added under MAC Filtering.

IPS/IDS

• Review the IPS/IDS Alerts to see if the packet was flagged as a threat.

Routing Issues

Branch to Branch and Branch to Branch via DC Connectivity Issues

• Ensure the NetBalancer gateway IP matches the branch’s specific tunnel IP.
  • Incorrect gateway IPs will misdirect packets, preventing proper routing.
  • Verify settings in the NetBalancer page.
• Ensure LAN subnets do not overlap across branches when using NetBalancer for LAN-to-LAN communication.
  • Verify subnet configurations on the Interfaces pages of each branch.