MicroShift is Developer Preview software only.
For more information about the support scope of Red Hat Developer Preview software, see Developer Preview Support Scope.Chapter 3. Troubleshooting
Read about troubleshooting and possible solutions for known issues.
3.1. Troubleshooting the NodePort service iptable rules
OVN-Kubernetes sets up an iptable chain in the network address translation (NAT) table to handle incoming traffic to the NodePort service. When the NodePort service is not reachable or the connection is refused, check the iptable rules on the host to make sure the relevant rules are properly inserted.
Procedure
View the iptable rules for the NodePort service by running the following command:
$ iptables-save | grep NODEPORT
Example output
-A OUTPUT -j OVN-KUBE-NODEPORT -A OVN-KUBE-NODEPORT -p tcp -m addrtype --dst-type LOCAL -m tcp --dport 30326 -j DNAT --to-destination 10.43.95.170:80
OVN-Kubernetes configures the
OVN-KUBE-NODEPORTiptable chain in the NAT table to match the destination port and Destination Network Address Translates (DNATs) the packet to theclusterIPservice. The packet is then routed to the OVN network through the gateway bridgebr-exvia routing rules on the host.Route the packet through the network with routing rules by running the following command:
$ ip route
Example output
10.43.0.0/16 via 192.168.122.1 dev br-ex mtu 1400
This routing rule matches the Kubernetes service IP address range and forwards the packet to the gateway bridge
br-ex. You must enableip_forwardon the host. After the packet is forwarded to the OVS bridgebr-ex, it is handled by OpenFlow rules in OVS which steers the packet to the OVN network and eventually to the pod.
