---

cat > /etc/net/ifaces/gre1/options << 'EOF'
TYPE=iptun
TUNTYPE=gre
TUNLOCAL=172.16.5.2
TUNREMOTE=172.16.4.2
TUNOPTIONS='ttl 64'
HOST=enp7s1
BOOTPROTO=static
MULTICAST=yes
EOF

systemctl restart network
ip link set gre1 up


cat > /etc/net/ifaces/gre1/options << 'EOF'
TYPE=iptun
TUNTYPE=gre
TUNLOCAL=172.16.4.2
TUNREMOTE=172.16.5.2
TUNOPTIONS='ttl 64'
HOST=enp7s1
BOOTPROTO=static
MULTICAST=yes
EOF

systemctl restart network
ip link set gre1 up

ping -c 3 10.0.0.1   # с BR-RTR — туннель должен пинговаться
vtysh -c "show ip ospf neighbor"  # должен появиться сосед