How to use NA and FNR?

Hi

i have file1:

conn=232257 client=16218.19488.218.86:51237 protocol=LDAP

file2:

conn=232257 dn="uid=apple,ou=xxxx,ou=usfgfhfers,dc=example,dc=com"
conn=232370 dn="uid=ball,ou=yyyyyy,ou=usfhfhfhers,dc=example,dc=com"

In the output file it should match first column from above both files then only it should add as below.
Required output should be with 4 columns

conn=232257 client=16218.19488.218.86:51237 protocol=LDAP dn="uid=apple,ou=xxxx,ou=usfgfhfers,dc=example,dc=com

awk 'NR==FNR {a[$1]=$2; next} $1 in a {print $0, a[$1]}' file2 file1

This is a duplicate of this thread.