Uneffective host name resolution under Sol 2.x?

[dasa123]

Dear all,

we are running under Solaris 2.7 the host name resolution via
this /etc/nsswitch.conf entry:

hosts: files nis dns

where the /var/yp/Makefile contains the line

B=-b

and the /etc/resolv.conf has these lines:

domain north.de.astrium.corp
nameserver 149.243.254.8
nameserver 149.243.254.6

Calling for examples

%ftp ftp.sun.com

we see that our Sun queries the 2 nameservers for

ftp.sun.com.north.de.astrium.corp

i.e. it appends the domain name from the /etc/resolv.conf
to the address.
Why does this happen respectively would the name resolution
not be faster without this suffix?

Many thanks for your suggestions, hints!