This scenario enables IPComp compression between roadwarrior carol and
gateway moon. Two IPv6 ICMP requests from carol to alice
check the established tunnel with compression. The packet sizes are different
because the kernel does not compress small packets.
Note: The kernel applies IPComp after fragmenting the original packet
according to the MTU. Also, because alice does not know about the IPsec
tunnel between moon and carol the response to the first ICMP
request is fragmented in too large fragments and moon sends back ICMPs
with type 2 to notify alice about this (Path MTU Discovery).
The second ping is then answered successfully.