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@enixdark
Forked from anfernee/conntrack-debug.md
Created July 17, 2022 11:09
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Node/Pod IP
Source Pod 10.11.1.103
Source Node 192.168.11.12
Gateway Node 192.168.11.11
External Service 192.168.11.13

iptables

Added the following on both source and gateway node. Egress gateway datapath still works.

   81  iptables -A INPUT -m state --state INVALID -j DROP
   82  iptables -A OUTPUT -m state --state INVALID -j DROP
   83  iptables -A FORWARD -m state --state INVALID -j DROP

Conntrack status

Source Pod

curl 196.168.11.13

Gateway Node

 [NEW] tcp      6 120 SYN_SENT src=10.11.1.103 dst=192.168.33.13 sport=33528 dport=80 [UNREPLIED] src=192.168.33.13 dst=10.11.1.103 sport=80 dport=33528
 [UPDATE] tcp      6 60 SYN_RECV src=10.11.1.103 dst=192.168.33.13 sport=33528 dport=80 src=192.168.33.13 dst=10.11.1.103 sport=80 dport=33528
 [UPDATE] tcp      6 86400 ESTABLISHED src=10.11.1.103 dst=192.168.33.13 sport=33528 dport=80 src=192.168.33.13 dst=10.11.1.103 sport=80 dport=33528 [ASSURED]
 [UPDATE] tcp      6 120 FIN_WAIT src=10.11.1.103 dst=192.168.33.13 sport=33528 dport=80 src=192.168.33.13 dst=10.11.1.103 sport=80 dport=33528 [ASSURED]
 [UPDATE] tcp      6 30 LAST_ACK src=10.11.1.103 dst=192.168.33.13 sport=33528 dport=80 src=192.168.33.13 dst=10.11.1.103 sport=80 dport=33528 [ASSURED]
 [UPDATE] tcp      6 120 TIME_WAIT src=10.11.1.103 dst=192.168.33.13 sport=33528 dport=80 src=192.168.33.13 dst=10.11.1.103 sport=80 dport=33528 [ASSURED]

Source Node

    [NEW] tcp      6 300 ESTABLISHED src=192.168.33.13 dst=10.11.1.103 sport=80 dport=33546 [UNREPLIED] src=10.11.1.103 dst=192.168.33.13 sport=33546 dport=80
 [UPDATE] tcp      6 120 FIN_WAIT src=192.168.33.13 dst=10.11.1.103 sport=80 dport=33546 [UNREPLIED] src=10.11.1.103 dst=192.168.33.13 sport=33546 dport=80
 [DESTROY] tcp      6 FIN_WAIT src=192.168.33.13 dst=10.11.1.103 sport=80 dport=33546 [UNREPLIED] src=10.11.1.103 dst=192.168.33.13 sport=33546 dport=80

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