ovs dec_ttl

#!/bin/sh

PATH=/mnt/host/src/redhat/ovs/utilities:$PATH

sysctl -qw net.ipv6.conf.all.disable_ipv6=1

ovs-dpctl add-dp dp

ip -b - <<'EOF'
netns add ns
netns exec ns sysctl -qw net.ipv6.conf.all.disable_ipv6=1
link add type veth
link add type veth peer name veth0 netns ns
link set veth0 up
link set veth1 up
link set veth2 up
addr add 192.168.0.1/24 dev veth0
link set veth0 up
EOF

ip -b - -n ns <<'EOF'
addr add 192.168.0.2/24 dev veth0
link set veth0 up
EOF

ovs-dpctl add-if dp veth1
ovs-dpctl add-if dp veth2
ovs-dpctl add-flow 'in_port(1),eth(),eth_type(0x806),arp()' 2
ovs-dpctl add-flow 'in_port(2),eth(),eth_type(0x806),arp()' 1
ovs-dpctl add-flow 'in_port(1),eth(),eth_type(0x800),ipv4()' dec_ttl,2
ovs-dpctl add-flow 'in_port(2),eth(),eth_type(0x800),ipv4()' dec_ttl,1

ip netns exec ns tcpdump -tvnni veth0 ip &
ping -qc1 -w1 -t 42 192.168.0.2