strace -f -s 1024 host ubuntu

gistfile1.txt

[pid 32630] socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP) = 6
[pid 32630] fcntl(6, F_DUPFD, 20)       = 20
[pid 32630] close(6)                    = 0
...
[pid 32630] bind(20, {sa_family=AF_INET, sin_port=htons(0), sin_addr=inet_addr("0.0.0.0")}, 16) = 0
...
[pid 32630] sendmsg(20, {msg_name(16)={sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("127.0.1.1")}, msg_iov(1)=[{"J\311\1\0\0\1\0\0\0\0\0\0\6ubuntu\0\0\1\0\1", 24}], msg_controllen=0, msg_flags=0}, 0 <unfinished ...>
...
[pid 32630] recvmsg(20, {msg_name(16)={sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("127.0.1.1")}, msg_iov(1)=[{"J\311\200\200\0\1\0\1\0\0\0\0\6ubuntu\0\0\1\0\1\300\f\0\1\0\1ZQ\1\343\0\4\300\250\1j", 65535}], msg_controllen=56, [{cmsg_len=32,
...
[pid 32630] write(1, "ubuntu has address 192.168.1.106\n", 33ubuntu has address 192.168.1.106