Comment 19 for bug 1791108

#VERIFICATION-BIONIC

- Before the update
ubuntu@iscsi-bionic:~$ dpkg -l | grep open-iscsi
ii open-iscsi 2.0.874-5ubuntu2.2 amd64 iSCSI initiator tools

ubuntu@iscsi-bionic:~$ cat /etc/resolv.conf
# Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)
# DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN
# 127.0.0.53 is the systemd-resolved stub resolver.
# run "systemd-resolve --status" to see details about the actual nameservers.

nameserver 192.168.122.1
domainsearch example.com

ubuntu@iscsi-bionic:~$ sudo strace ping -c1 www 2>&1 | grep www
execve("/bin/ping", ["ping", "-c1", "www"], 0x7ffeb4aecd70 /* 14 vars */) = 0
sendmmsg(5, [{msg_hdr={msg_name=NULL, msg_namelen=0, msg_iov=[{iov_base="\300\17\1\0\0\1\0\0\0\0\0\0\3www\0\0\1\0\1", iov_len=21}], msg_iovlen=1, msg_controllen=0, msg_flags=MSG_TRUNC|MSG_DONTWAIT|MSG_EOR|MSG_WAITALL|MSG_CONFIRM|MSG_RST|MSG_MORE|MSG_BATCH|MSG_ZEROCOPY|MSG_FASTOPEN|0xb420000}, msg_len=21}, {msg_hdr={msg_name=NULL, msg_namelen=0, msg_iov=[{iov_base="\0\31\1\0\0\1\0\0\0\0\0\0\3www\0\0\34\0\1", iov_len=21}], msg_iovlen=1, msg_controllen=0, msg_flags=MSG_CTRUNC|MSG_FIN|MSG_SYN|MSG_CONFIRM|MSG_RST|MSG_MORE|MSG_BATCH|MSG_ZEROCOPY|MSG_FASTOPEN|0xb420010}, msg_len=21}], 2, MSG_NOSIGNAL) = 2
recvfrom(5, "\300\17\201\203\0\1\0\0\0\0\0\0\3www\0\0\1\0\1", 2048, 0, {sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("192.168.122.1")}, [28->16]) = 21
recvfrom(5, "\0\31\201\203\0\1\0\0\0\1\0\0\3www\0\0\34\0\1\0\0\6\0\1\0\0\"L\0@"..., 65536, 0, {sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("192.168.122.1")}, [28->16]) = 96
write(2, "ping: www: Name or service not k"..., 37ping: www: Name or service not known

- After the update
ubuntu@iscsi-bionic:~$ dpkg -l | grep open-iscsi
ii open-iscsi 2.0.874-5ubuntu2.3 amd64 iSCSI initiator tools

ubuntu@iscsi-bionic:~$ cat /etc/resolv.conf
# Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)
# DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN
# 127.0.0.53 is the systemd-resolved stub resolver.
# run "systemd-resolve --status" to see details about the actual nameservers.

nameserver 192.168.122.1
search example.com

ubuntu@iscsi-bionic:~$ sudo strace ping -c1 www 2>&1 | grep www
execve("/bin/ping", ["ping", "-c1", "www"], 0x7ffea5cd0390 /* 14 vars */) = 0
sendmmsg(5, [{msg_hdr={msg_name=NULL, msg_namelen=0, msg_iov=[{iov_base="\262\224\1\0\0\1\0\0\0\0\0\0\3www\7example\3com\0\0\1\0"..., iov_len=33}], msg_iovlen=1, msg_controllen=0, msg_flags=MSG_TRUNC|MSG_DONTWAIT|MSG_EOR|MSG_WAITALL|MSG_CONFIRM|MSG_ERRQUEUE|MSG_NOSIGNAL|MSG_MORE|MSG_BATCH|MSG_ZEROCOPY|MSG_CMSG_CLOEXEC|0x1b480000}, msg_len=33}, {msg_hdr={msg_name=NULL, msg_namelen=0, msg_iov=[{iov_base="\226\235\1\0\0\1\0\0\0\0\0\0\3www\7example\3com\0\0\34\0"..., iov_len=33}], msg_iovlen=1, msg_controllen=0, msg_flags=MSG_CTRUNC|MSG_FIN|MSG_SYN|MSG_CONFIRM|MSG_ERRQUEUE|MSG_NOSIGNAL|MSG_MORE|MSG_BATCH|MSG_ZEROCOPY|MSG_CMSG_CLOEXEC|0x1b480010}, msg_len=33}], 2, MSG_NOSIGNAL) = 2
recvfrom(5, "\262\224\201\200\0\1\0\1\0\0\0\0\3www\7example\3com\0\0\1\0"..., 2048, 0, {sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("192.168.122.1")}, [28->16]) = 49
recvfrom(5, "\226\235\201\200\0\1\0\1\0\2\0\4\3www\7example\3com\0\0\34\0"..., 65536, 0, {sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("192.168.122.1")}, [28->16]) = 197
write(1, "PING www.example.com (93.184.216"..., 132PING www.example.com (93.184.216.34) 56(84) bytes of data.
write(1, "--- www.example.com ping statist"..., 114--- www.example.com ping statistics ---