Function create_udp_trace 

pub fn create_udp_trace(
    src: &Address,
    dst: &Address,
    sport: u16,
    dport: u16,
    identifier: u16,
    desired_checksum: u16,
    id: &TraceDnsId<'_>,
) -> Vec<u8> 

Creates a UDP (Paris) traceroute probe packet with a DNS payload

When the probe reaches its destination DNS server, the server replies to the DNS query, resulting in the traceroute being terminated (destination reached).

Encoding scheme:

• IPv4 IP identification (16b) / IPv6 flow label (16b of 20b): (worker_hi_2 << 14) | timestamp_14b
• UDP checksum (16b): (ttl << 8) | worker_lo_8

Arguments

• src / dst - source / destination address
• sport / dport - configured ports (constant across probes for Paris)
• identifier - IP identification / flow label (worker_hi + timestamp)
• desired_checksum - value forced into the UDP checksum (ttl + worker_lo)
• id - probe identity encoded in the QNAME (worker, measurement, send time, TTL)