I've heard that such servers are on the same layer 2 LAN with others, making them subject to a variety of attacks such as ARP poisoning or RA Flood attacks, and I realized that would be easy to test with ping6.
Here are my results--172 links on my LAN, and they are all unique!
That means any of them could attack me, and I could attack them all.
A pretty scary thought, as everyone races to the cloud, mostly imagining that the cloud providers are protecting them.
root@sbowne:~# ping6 -I eth0 -i 10 ff02::1
PING ff02::1(ff02::1) from fe80::216:3eff:fe36:efc1 eth0: 56 data bytes
64 bytes from fe80::216:3eff:fe36:efc1: icmp_seq=1 ttl=64 time=0.042 ms
64 bytes from fe80::225:90ff:fe91:e768: icmp_seq=1 ttl=64 time=4.75 ms (DUP!)
64 bytes from fe80::216:3eff:fe27:a2af: icmp_seq=1 ttl=64 time=4.79 ms (DUP!)
64 bytes from fe80::216:3eff:fe5f:639d: icmp_seq=1 ttl=64 time=4.79 ms (DUP!)
64 bytes from fe80::216:3eff:fef5:b796: icmp_seq=1 ttl=64 time=4.80 ms (DUP!)
64 bytes from fe80::216:3eff:feb3:1acf: icmp_seq=1 ttl=64 time=4.80 ms (DUP!)
64 bytes from fe80::216:3eff:febe:3fa5: icmp_seq=1 ttl=64 time=4.81 ms (DUP!)
64 bytes from fe80::216:3eff:fe2d:5742: icmp_seq=1 ttl=64 time=4.81 ms (DUP!)
64 bytes from fe80::216:3eff:fe6a:f4e4: icmp_seq=1 ttl=64 time=4.81 ms (DUP!)
64 bytes from fe80::216:3eff:fe2b:f61c: icmp_seq=1 ttl=64 time=4.82 ms (DUP!)
64 bytes from fe80::216:3eff:fef6:71a6: icmp_seq=1 ttl=64 time=4.82 ms (DUP!)
64 bytes from fe80::216:3eff:fe9c:408a: icmp_seq=1 ttl=64 time=4.83 ms (DUP!)
64 bytes from fe80::216:3eff:fef9:3276: icmp_seq=1 ttl=64 time=4.83 ms (DUP!)
64 bytes from fe80::216:3eff:fe0e:7518: icmp_seq=1 ttl=64 time=4.84 ms (DUP!)
64 bytes from fe80::216:3eff:feeb:9b47: icmp_seq=1 ttl=64 time=6.33 ms (DUP!)
64 bytes from fe80::216:3eff:fe59:633a: icmp_seq=1 ttl=255 time=6.34 ms (DUP!)
64 bytes from fe80::216:3eff:fea5:d3a: icmp_seq=1 ttl=64 time=6.34 ms (DUP!)
64 bytes from fe80::216:3eff:fee8:747e: icmp_seq=1 ttl=255 time=6.35 ms (DUP!)
64 bytes from fe80::216:3eff:fecb:3c95: icmp_seq=1 ttl=64 time=6.35 ms (DUP!)
64 bytes from fe80::216:3eff:fe3f:8b3d: icmp_seq=1 ttl=64 time=6.35 ms (DUP!)
64 bytes from fe80::216:3eff:fea0:7af5: icmp_seq=1 ttl=64 time=6.35 ms (DUP!)
64 bytes from fe80::216:3eff:fe71:2e2a: icmp_seq=1 ttl=64 time=6.36 ms (DUP!)
64 bytes from fe80::216:3eff:fe47:4615: icmp_seq=1 ttl=64 time=6.36 ms (DUP!)
64 bytes from fe80::216:3eff:fe85:9ab8: icmp_seq=1 ttl=64 time=6.36 ms (DUP!)
64 bytes from fe80::216:3eff:fe68:cfd5: icmp_seq=1 ttl=64 time=6.36 ms (DUP!)
64 bytes from fe80::216:3eff:fe70:91f5: icmp_seq=1 ttl=64 time=6.37 ms (DUP!)
64 bytes from fe80::216:3eff:fea9:b153: icmp_seq=1 ttl=64 time=6.37 ms (DUP!)
64 bytes from fe80::216:3eff:fe61:2b1c: icmp_seq=1 ttl=64 time=6.37 ms (DUP!)
64 bytes from fe80::216:3eff:fedc:e1eb: icmp_seq=1 ttl=64 time=6.37 ms (DUP!)
64 bytes from fe80::216:3eff:fe3f:9b96: icmp_seq=1 ttl=64 time=6.38 ms (DUP!)
64 bytes from fe80::216:3eff:feb2:3782: icmp_seq=1 ttl=64 time=6.38 ms (DUP!)
64 bytes from fe80::216:3eff:feb7:b33d: icmp_seq=1 ttl=64 time=6.38 ms (DUP!)
64 bytes from fe80::216:3eff:fef7:fb7: icmp_seq=1 ttl=64 time=6.38 ms (DUP!)
64 bytes from fe80::216:3eff:fe91:1b61: icmp_seq=1 ttl=64 time=6.39 ms (DUP!)
64 bytes from fe80::216:3eff:fe26:a06: icmp_seq=1 ttl=64 time=6.39 ms (DUP!)
64 bytes from fe80::216:3eff:fe34:5229: icmp_seq=1 ttl=64 time=6.39 ms (DUP!)
64 bytes from fe80::216:3eff:fe53:3867: icmp_seq=1 ttl=64 time=6.39 ms (DUP!)
64 bytes from fe80::216:3eff:fec2:b49e: icmp_seq=1 ttl=64 time=8.03 ms (DUP!)
64 bytes from fe80::216:3eff:fe9b:2897: icmp_seq=1 ttl=64 time=8.04 ms (DUP!)
64 bytes from fe80::216:3eff:fe29:6efe: icmp_seq=1 ttl=64 time=8.04 ms (DUP!)
64 bytes from fe80::216:3eff:fe25:4ab6: icmp_seq=1 ttl=64 time=8.05 ms (DUP!)
64 bytes from fe80::216:3eff:feb2:8397: icmp_seq=1 ttl=64 time=8.05 ms (DUP!)
64 bytes from fe80::216:3eff:fe1c:f7b0: icmp_seq=1 ttl=64 time=8.05 ms (DUP!)
64 bytes from fe80::216:3eff:fe5c:815e: icmp_seq=1 ttl=64 time=8.06 ms (DUP!)
64 bytes from fe80::216:3eff:fee9:8a0c: icmp_seq=1 ttl=64 time=8.06 ms (DUP!)
64 bytes from fe80::216:3eff:fed5:f9a8: icmp_seq=1 ttl=64 time=8.06 ms (DUP!)
64 bytes from fe80::216:3eff:fe4e:af5d: icmp_seq=1 ttl=255 time=8.06 ms (DUP!)
64 bytes from fe80::216:3eff:febe:35d1: icmp_seq=1 ttl=64 time=8.06 ms (DUP!)
64 bytes from fe80::216:3eff:fe60:921f: icmp_seq=1 ttl=64 time=8.07 ms (DUP!)
64 bytes from fe80::216:3eff:fee6:818e: icmp_seq=1 ttl=64 time=8.07 ms (DUP!)
64 bytes from fe80::216:3eff:fe8b:808c: icmp_seq=1 ttl=255 time=8.07 ms (DUP!)
64 bytes from fe80::216:3eff:fe56:8bd: icmp_seq=1 ttl=64 time=8.07 ms (DUP!)
64 bytes from fe80::216:3eff:fe23:9c3e: icmp_seq=1 ttl=64 time=8.08 ms (DUP!)
64 bytes from fe80::216:3eff:fe69:b54f: icmp_seq=1 ttl=255 time=8.08 ms (DUP!)
64 bytes from fe80::216:3eff:fe26:f21a: icmp_seq=1 ttl=64 time=8.08 ms (DUP!)
64 bytes from fe80::216:3eff:fe85:7b72: icmp_seq=1 ttl=64 time=8.08 ms (DUP!)
64 bytes from fe80::216:3eff:fe4a:51c5: icmp_seq=1 ttl=64 time=8.09 ms (DUP!)
64 bytes from fe80::216:3eff:fe23:9efb: icmp_seq=1 ttl=64 time=8.09 ms (DUP!)
64 bytes from fe80::216:3eff:fe71:c738: icmp_seq=1 ttl=64 time=8.10 ms (DUP!)
64 bytes from fe80::216:3eff:fe4f:28e9: icmp_seq=1 ttl=255 time=8.10 ms (DUP!)
64 bytes from fe80::216:3eff:fee8:a2e6: icmp_seq=1 ttl=255 time=8.25 ms (DUP!)
64 bytes from fe80::216:3eff:fe42:f4f7: icmp_seq=1 ttl=64 time=8.25 ms (DUP!)
64 bytes from fe80::216:3eff:febc:28d1: icmp_seq=1 ttl=255 time=8.26 ms (DUP!)
64 bytes from fe80::216:3eff:fe1e:309e: icmp_seq=1 ttl=64 time=8.26 ms (DUP!)
64 bytes from fe80::216:3eff:fe7a:769a: icmp_seq=1 ttl=64 time=8.26 ms (DUP!)
64 bytes from fe80::216:3eff:fe7c:7e85: icmp_seq=1 ttl=64 time=8.26 ms (DUP!)
64 bytes from fe80::216:3eff:fef5:c729: icmp_seq=1 ttl=64 time=8.26 ms (DUP!)
64 bytes from fe80::216:3eff:fe31:258d: icmp_seq=1 ttl=255 time=8.27 ms (DUP!)
64 bytes from fe80::216:3eff:fe3a:5a8c: icmp_seq=1 ttl=64 time=8.27 ms (DUP!)
64 bytes from fe80::216:3eff:fe6b:f4c1: icmp_seq=1 ttl=255 time=8.27 ms (DUP!)
64 bytes from fe80::216:3eff:fe03:42ea: icmp_seq=1 ttl=64 time=8.27 ms (DUP!)
64 bytes from fe80::216:3eff:fe23:19e7: icmp_seq=1 ttl=64 time=8.27 ms (DUP!)
64 bytes from fe80::216:3eff:fee8:43df: icmp_seq=1 ttl=64 time=8.28 ms (DUP!)
64 bytes from fe80::216:3eff:fe03:979b: icmp_seq=1 ttl=64 time=8.28 ms (DUP!)
64 bytes from fe80::216:3eff:fe3b:d0f3: icmp_seq=1 ttl=64 time=8.28 ms (DUP!)
64 bytes from fe80::216:3eff:fe2b:53d5: icmp_seq=1 ttl=255 time=8.28 ms (DUP!)
64 bytes from fe80::216:3eff:fe09:4017: icmp_seq=1 ttl=64 time=8.28 ms (DUP!)
64 bytes from fe80::216:3eff:fe7e:5cef: icmp_seq=1 ttl=64 time=8.29 ms (DUP!)
64 bytes from fe80::216:3eff:fe27:b2c2: icmp_seq=1 ttl=64 time=8.29 ms (DUP!)
64 bytes from fe80::216:3eff:feb5:5635: icmp_seq=1 ttl=64 time=8.29 ms (DUP!)
64 bytes from fe80::216:3eff:fe82:a90e: icmp_seq=1 ttl=64 time=8.29 ms (DUP!)
64 bytes from fe80::216:3eff:fee7:b1fe: icmp_seq=1 ttl=255 time=8.30 ms (DUP!)
64 bytes from fe80::216:3eff:fe04:e7c1: icmp_seq=1 ttl=64 time=8.30 ms (DUP!)
64 bytes from fe80::216:3eff:fed8:61fd: icmp_seq=1 ttl=64 time=8.54 ms (DUP!)
64 bytes from fe80::216:3eff:fe70:9d1f: icmp_seq=1 ttl=64 time=8.55 ms (DUP!)
64 bytes from fe80::216:3eff:fe3b:b6a5: icmp_seq=1 ttl=64 time=8.55 ms (DUP!)
64 bytes from fe80::216:3eff:fed2:aec8: icmp_seq=1 ttl=255 time=8.55 ms (DUP!)
64 bytes from fe80::216:3eff:fe06:24d8: icmp_seq=1 ttl=64 time=8.55 ms (DUP!)
64 bytes from fe80::216:3eff:fef2:edca: icmp_seq=1 ttl=255 time=8.55 ms (DUP!)
64 bytes from fe80::216:3eff:fead:a90c: icmp_seq=1 ttl=64 time=8.56 ms (DUP!)
64 bytes from fe80::216:3eff:fead:54d4: icmp_seq=1 ttl=64 time=8.56 ms (DUP!)
64 bytes from fe80::216:3eff:fe78:9cfa: icmp_seq=1 ttl=64 time=8.56 ms (DUP!)
64 bytes from fe80::216:3eff:feaf:ed37: icmp_seq=1 ttl=64 time=8.56 ms (DUP!)
64 bytes from fe80::216:3eff:fef9:cbe8: icmp_seq=1 ttl=64 time=8.56 ms (DUP!)
64 bytes from fe80::216:3eff:fe84:3657: icmp_seq=1 ttl=64 time=8.56 ms (DUP!)
64 bytes from fe80::216:3eff:fe89:9b4f: icmp_seq=1 ttl=64 time=8.57 ms (DUP!)
64 bytes from fe80::216:3eff:fe68:c45e: icmp_seq=1 ttl=64 time=8.57 ms (DUP!)
64 bytes from fe80::216:3eff:fe3e:9b10: icmp_seq=1 ttl=64 time=8.57 ms (DUP!)
64 bytes from fe80::216:3eff:fef5:65d8: icmp_seq=1 ttl=64 time=8.57 ms (DUP!)
64 bytes from fe80::216:3eff:fe30:9551: icmp_seq=1 ttl=64 time=8.57 ms (DUP!)
64 bytes from fe80::216:3eff:fe86:ecfb: icmp_seq=1 ttl=64 time=8.58 ms (DUP!)
64 bytes from fe80::216:3eff:febc:b624: icmp_seq=1 ttl=64 time=8.58 ms (DUP!)
64 bytes from fe80::216:3eff:fe89:4779: icmp_seq=1 ttl=64 time=8.58 ms (DUP!)
64 bytes from fe80::216:3eff:fedf:a304: icmp_seq=1 ttl=255 time=8.58 ms (DUP!)
64 bytes from fe80::216:3eff:feec:f730: icmp_seq=1 ttl=64 time=8.59 ms (DUP!)
64 bytes from fe80::216:3eff:fec9:4501: icmp_seq=1 ttl=64 time=8.59 ms (DUP!)
64 bytes from fe80::216:3eff:fe81:a0f9: icmp_seq=1 ttl=64 time=8.75 ms (DUP!)
64 bytes from fe80::216:3eff:fecf:6494: icmp_seq=1 ttl=64 time=8.76 ms (DUP!)
64 bytes from fe80::216:3eff:fe4d:1b64: icmp_seq=1 ttl=64 time=8.76 ms (DUP!)
64 bytes from fe80::216:3eff:fe37:707b: icmp_seq=1 ttl=64 time=8.77 ms (DUP!)
64 bytes from fe80::216:3eff:fe1f:f8c8: icmp_seq=1 ttl=64 time=8.77 ms (DUP!)
64 bytes from fe80::216:3eff:feb8:3b6e: icmp_seq=1 ttl=64 time=8.77 ms (DUP!)
64 bytes from fe80::216:3eff:fe53:3adc: icmp_seq=1 ttl=64 time=8.78 ms (DUP!)
64 bytes from fe80::216:3eff:fede:6a04: icmp_seq=1 ttl=64 time=8.78 ms (DUP!)
64 bytes from fe80::216:3eff:fed0:8dbc: icmp_seq=1 ttl=64 time=8.78 ms (DUP!)
64 bytes from fe80::216:3eff:fefa:6bd7: icmp_seq=1 ttl=64 time=8.78 ms (DUP!)
64 bytes from fe80::216:3eff:fe96:ea1a: icmp_seq=1 ttl=64 time=8.79 ms (DUP!)
64 bytes from fe80::216:3eff:fe6e:96d0: icmp_seq=1 ttl=64 time=8.79 ms (DUP!)
64 bytes from fe80::216:3eff:fe6a:703: icmp_seq=1 ttl=64 time=8.79 ms (DUP!)
64 bytes from fe80::216:3eff:fe36:43bc: icmp_seq=1 ttl=64 time=8.80 ms (DUP!)
64 bytes from fe80::216:3eff:fe87:3f5a: icmp_seq=1 ttl=64 time=8.80 ms (DUP!)
64 bytes from fe80::216:3eff:fe0d:2d2c: icmp_seq=1 ttl=64 time=8.80 ms (DUP!)
64 bytes from fe80::216:3eff:fe41:3081: icmp_seq=1 ttl=64 time=8.81 ms (DUP!)
64 bytes from fe80::216:3eff:fe6c:3b6: icmp_seq=1 ttl=64 time=8.81 ms (DUP!)
64 bytes from fe80::216:3eff:fe49:676b: icmp_seq=1 ttl=64 time=8.81 ms (DUP!)
64 bytes from fe80::216:3eff:fed7:a606: icmp_seq=1 ttl=255 time=8.82 ms (DUP!)
64 bytes from fe80::216:3eff:fe28:c9e6: icmp_seq=1 ttl=64 time=8.82 ms (DUP!)
64 bytes from fe80::216:3eff:fecf:6c17: icmp_seq=1 ttl=64 time=8.82 ms (DUP!)
64 bytes from fe80::216:3eff:feaf:befd: icmp_seq=1 ttl=64 time=8.83 ms (DUP!)
64 bytes from fe80::216:3eff:fe87:e93d: icmp_seq=1 ttl=64 time=9.33 ms (DUP!)
64 bytes from fe80::216:3eff:fefd:ea3d: icmp_seq=1 ttl=64 time=9.34 ms (DUP!)
64 bytes from fe80::216:3eff:fe4b:8597: icmp_seq=1 ttl=64 time=9.34 ms (DUP!)
64 bytes from fe80::216:3eff:fea1:8df4: icmp_seq=1 ttl=64 time=9.34 ms (DUP!)
64 bytes from fe80::216:3eff:fe6a:e0b1: icmp_seq=1 ttl=64 time=9.35 ms (DUP!)
64 bytes from fe80::216:3eff:fe0f:b69e: icmp_seq=1 ttl=64 time=9.35 ms (DUP!)
64 bytes from fe80::216:3eff:fedb:cce: icmp_seq=1 ttl=64 time=9.35 ms (DUP!)
64 bytes from fe80::216:3eff:fece:d9b4: icmp_seq=1 ttl=64 time=9.36 ms (DUP!)
64 bytes from fe80::216:3eff:fefe:5634: icmp_seq=1 ttl=64 time=9.36 ms (DUP!)
64 bytes from fe80::216:3eff:fe47:af6a: icmp_seq=1 ttl=64 time=9.36 ms (DUP!)
64 bytes from fe80::216:3eff:fe59:408c: icmp_seq=1 ttl=64 time=9.37 ms (DUP!)
64 bytes from fe80::216:3eff:fe91:5486: icmp_seq=1 ttl=64 time=9.37 ms (DUP!)
64 bytes from fe80::216:3eff:fe57:c567: icmp_seq=1 ttl=64 time=9.37 ms (DUP!)
64 bytes from fe80::216:3eff:fe0c:38d0: icmp_seq=1 ttl=64 time=9.38 ms (DUP!)
64 bytes from fe80::216:3eff:feb7:9d94: icmp_seq=1 ttl=64 time=9.38 ms (DUP!)
64 bytes from fe80::216:3eff:fe2b:7117: icmp_seq=1 ttl=255 time=9.38 ms (DUP!)
64 bytes from fe80::216:3eff:fe1d:7194: icmp_seq=1 ttl=64 time=9.39 ms (DUP!)
64 bytes from fe80::216:3eff:fec8:42ea: icmp_seq=1 ttl=64 time=9.39 ms (DUP!)
64 bytes from fe80::216:3eff:fe19:3e5a: icmp_seq=1 ttl=64 time=9.39 ms (DUP!)
64 bytes from fe80::216:3eff:fe05:b680: icmp_seq=1 ttl=64 time=9.39 ms (DUP!)
64 bytes from fe80::216:3eff:fe41:8424: icmp_seq=1 ttl=64 time=9.40 ms (DUP!)
64 bytes from fe80::216:3eff:fe7e:a0b3: icmp_seq=1 ttl=64 time=9.40 ms (DUP!)
64 bytes from fe80::216:3eff:fe63:536e: icmp_seq=1 ttl=64 time=9.40 ms (DUP!)
64 bytes from fe80::216:3eff:fec8:737: icmp_seq=1 ttl=64 time=9.58 ms (DUP!)
64 bytes from fe80::216:3eff:fea3:2fef: icmp_seq=1 ttl=64 time=9.59 ms (DUP!)
64 bytes from fe80::216:3eff:fe6d:b2ba: icmp_seq=1 ttl=64 time=9.59 ms (DUP!)
64 bytes from fe80::216:3eff:fe40:abd0: icmp_seq=1 ttl=64 time=9.59 ms (DUP!)
64 bytes from fe80::216:3eff:fe35:f5e1: icmp_seq=1 ttl=64 time=9.60 ms (DUP!)
64 bytes from fe80::216:3eff:feda:2384: icmp_seq=1 ttl=64 time=9.60 ms (DUP!)
64 bytes from fe80::216:3eff:fe7e:5960: icmp_seq=1 ttl=255 time=9.60 ms (DUP!)
64 bytes from fe80::216:3eff:fee0:d713: icmp_seq=1 ttl=64 time=9.61 ms (DUP!)
64 bytes from fe80::216:3eff:fee8:1701: icmp_seq=1 ttl=64 time=9.61 ms (DUP!)
64 bytes from fe80::216:3eff:fed3:df01: icmp_seq=1 ttl=64 time=9.61 ms (DUP!)
64 bytes from fe80::216:3eff:fe26:19b8: icmp_seq=1 ttl=64 time=9.62 ms (DUP!)
64 bytes from fe80::216:3eff:fe4b:6830: icmp_seq=1 ttl=64 time=9.62 ms (DUP!)
64 bytes from fe80::216:3eff:fe4f:d178: icmp_seq=1 ttl=64 time=9.62 ms (DUP!)
64 bytes from fe80::216:3eff:fe68:87a5: icmp_seq=1 ttl=64 time=9.63 ms (DUP!)
64 bytes from fe80::216:3eff:fe56:70d8: icmp_seq=1 ttl=64 time=9.63 ms (DUP!)
64 bytes from fe80::216:3eff:fe60:1890: icmp_seq=1 ttl=64 time=9.63 ms (DUP!)
64 bytes from fe80::216:3eff:fea8:af50: icmp_seq=1 ttl=64 time=9.64 ms (DUP!)
64 bytes from fe80::216:3eff:fe5e:4d8c: icmp_seq=1 ttl=64 time=9.64 ms (DUP!)
64 bytes from fe80::216:3eff:feb4:5931: icmp_seq=1 ttl=64 time=9.83 ms (DUP!)
64 bytes from fe80::216:3eff:fe5e:edb0: icmp_seq=1 ttl=64 time=9.83 ms (DUP!)
^C
--- ff02::1 ping statistics ---
1 packets transmitted, 1 received, +171 duplicates, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.042/8.098/9.839/1.479 ms
root@sbowne:~#
That's normal--people usually block layer 3 broadcasts, but it is traditional to ignore layer 2.