4.5. NETINFO cells

   If version 2 or higher is negotiated, each party sends the other a
   NETINFO cell.  The cell's payload is:

         Timestamp              [4 bytes]
         Other OR's address     [variable]
         Number of addresses    [1 byte]
         This OR's addresses    [variable]

   The address format is a type/length/value sequence as given in
   section 6.4 below, without the final TTL.  The timestamp is a
   big-endian unsigned integer number of seconds since the Unix epoch.

...

6.4. Remote hostname lookup

...

       Type   (1 octet)
       Length (1 octet)
       Value  (variable-width)
       TTL    (4 octets)
   "Length" is the length of the Value field.
   "Type" is one of:
      0x00 -- Hostname
      0x04 -- IPv4 address
      0x06 -- IPv6 address
      0xF0 -- Error, transient
      0xF1 -- Error, nontransient