A connection between the subnets behind the gateways <b>moon</b> and <b>sun</b> is set up.
The authentication is based on <b>X.509 certificates</b>. With <b>ah=sha256-sha384</b>
gateway <b>moon</b> proposes the use of <b>AH</b>. Gateway <b>sun</b> selects HMAC_SHA2_256_128
for integrity protection with its <b>ah=sha256</b> configuration.
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Upon the successful establishment of the IPsec tunnel, the updown script automatically
inserts iptables-based firewall rules that let pass the tunneled traffic.
In order to test both tunnel and firewall, client <b>alice</b> behind gateway <b>moon</b>
pings client <b>bob</b> located behind gateway <b>sun</b>.
