IPSEC VPN | Notion

Use TCPdump to capture the live traffic by using the below command.

For LAN traffic

# tcpdump -nni eth0 host 192.168.0.2

Note: eth0 is LAN interface and 192.168.0.2 is server IP.

For WAN IPsec Traffic

# tcpdump -nni eth2 esp

Note: eth2 is WAN interface and ESP shows encrypted packet

tcpdump -nni eth1 port 500 or port 4500

eth1 - WAN Interface

tcpdump -nni any host 192.168.2.32 and 192.168.3.244

IPSec VPN Troubleshooting Decision Diagram