icmpTypeV6:
| ""
| "address-unreachable"
| "bad-header"
| "communication-prohibited"
| "destination-unreachable"
| "echo-reply"
| "echo-request"
| "neighbor-advertisement"
| "neighbor-solicitation"
| "no-route"
| "packet-too-big"
| "parameter-problem"
| "port-unreachable"
| "redirect"
| "router-advertisement"
| "router-solicitation"
| "time-exceeded"
| "ttl-zero-during-reassembly"
| "ttl-zero-during-transit"
| "unknown-header-type"
| "unknown-option"
| string