For same protocol numbers (e.g. IP 4o4), use Outer/Inner as prefix. For
"similar" protocols like VlanStack or IP 4o6, use the protocol name as
the prefix.
For UDP encaps like VxLAN or Geneve, which can contain IP as
payload, the UDP checksum was incorrect because when summing
UDP payload (i.e. IP), we skipped the IPv4 checksum field,
which should not be skipped in this case.
Similar issue, for ICMP with IP as payload, ICMP checksum was
incorrect.
Essentially, any protocol which checksums over its payload and
the payload contains protocols with checksum fields.
