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Diffstat (limited to 'src/plugins/nat/nat44-ei/nat44_ei_ha_doc.rst')
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diff --git a/src/plugins/nat/nat44-ei/nat44_ei_ha_doc.rst b/src/plugins/nat/nat44-ei/nat44_ei_ha_doc.rst new file mode 100644 index 00000000000..46befc52351 --- /dev/null +++ b/src/plugins/nat/nat44-ei/nat44_ei_ha_doc.rst @@ -0,0 +1,88 @@ +Active-Passive NAT HA +===================== + +Introduction +------------ + +One NAT node actively manages traffic while the other is synchronized +and ready to transition to the active state and takes over seamlessly +and enforces the same NAT sessions when failure occur. Both nodes share +the same configuration settings. + +Configuration +------------- + +NAT HA protocol +~~~~~~~~~~~~~~~ + +Session synchronization traffic is distributed through an IPv4 UDP +connection. The active node sends NAT HA protocol events to passive +node. To achieve reliable transfer NAT HA protocol uses acknowledgment +with re-transmission. This require the passive node to respond with an +acknowledgment message as it receives the data. The active node keeps a +record of each packet it sends and maintains a timer from when the +packet was sent. The active node re-transmits a packet if the timer +expires before receiving the acknowledgment. + +Topology +~~~~~~~~ + +The two NAT nodes have a dedicated link (interface GE0/0/3 on both) to +synchronize NAT sessions using NAT HA protocol. + +:: + + +-----------------------+ + | outside network | + +-----------------------+ + / \ + / \ + / \ + / \ + / \ + +---------+ +---------+ + | GE0/0/1 | Active Passive | GE0/0/1 | + | | | | + | GE0/0/3|-------------------|GE0/0/3 | + | | sync network | | + | GE0/0/0 | | GE0/0/0 | + +---------+ +---------+ + \ / + \ / + \ / + \ / + \ / + +-----------------------+ + | inside network | + +-----------------------+ + +Active node configuration +~~~~~~~~~~~~~~~~~~~~~~~~~ + +:: + + set interface ip address GigabitEthernet0/0/1 10.15.7.101/24 + set interface ip address GigabitEthernet0/0/0 172.16.10.101/24 + set interface ip address GigabitEthernet0/0/3 10.0.0.1/24 + set interface state GigabitEthernet0/0/0 up + set interface state GigabitEthernet0/0/1 up + set interface state GigabitEthernet0/0/3 up + set interface nat44 in GigabitEthernet0/0/0 out GigabitEthernet0/0/1 + nat44 add address 10.15.7.100 + nat ha listener 10.0.0.1:1234 + nat ha failover 10.0.0.2:2345 + +Passive node configuration +~~~~~~~~~~~~~~~~~~~~~~~~~~ + +:: + + set interface ip address GigabitEthernet0/0/1 10.15.7.102/24 + set interface ip address GigabitEthernet0/0/0 172.16.10.102/24 + set interface ip address GigabitEthernet0/0/3 10.0.0.2/24 + set interface state GigabitEthernet0/0/0 up + set interface state GigabitEthernet0/0/1 up + set interface state GigabitEthernet0/0/3 up + set interface nat44 in GigabitEthernet0/0/0 out GigabitEthernet0/0/1 + nat44 add address 10.15.7.100 + nat ha listener 10.0.0.2:2345 |