-set(ipv4_tunnel(tun_id=0xabcdef1234567890,flags=0x0,src=1.1.1.1,dst=2.2.2.2,tos=0x0,ttl=64))
+set(ipv4_tunnel(tun_id=0xabcdef1234567890,src=1.1.1.1,dst=2.2.2.2,tos=0x0,ttl=64,flags(df,csum,key)))
+set(ipv4_tunnel(tun_id=0xabcdef1234567890,src=1.1.1.1,dst=2.2.2.2,tos=0x0,ttl=64,flags(df,csum,key,0x20)))
+set(ipv4_tunnel(tun_id=0xabcdef1234567890,src=1.1.1.1,dst=2.2.2.2,tos=0x0,ttl=64,flags()))