Help with rarp compilation!

Hi! 
I needed to install rarpd on my slack 9.0 with 2.4.27 kernel.
i downloaded rarpd 1.1 which needs libpcap and libnet.
I also downloaded libpcap, compiled it without error and libnet 1.1.2.1 too.
The snag is when i configure rarpd.
I run ./configure and then it tells me this:

checking for libnet library in /usr/ng/lib... not found
checking for libnet library in /usr/lib... not found
checking for libnet library in /usr/local/lib... not found
checking whether to include libnet... no

it seems it is not finding libnet libraries!! 
i am getting crazy with this!
Is there something i should know that i dont?
because libnet.a is there.. is @/usr/lib and i copied it @/usr/local/lib too 

i am compiling everything from /usr/local/src/ but asking configure to install architecture-independent files in /usr :
./configure --prefix=/usr

nothing seems to be working .. 
because when i run "make" @rarpd this is what happens:

root@dodo:/usr/local/src/rarpd-1.1# make
gcc -g -O2   -D_BSD_SOURCE -D__BSD_SOURCE -D__FAVOR_BSD -DHAVE_NET_ETHERNET_H -I/usr/include -I/usr
/local/src/libnet/include  -DPACKAGE=\"\" -DVERSION=\"\" -DSTDC_HEADERS=1 -DHAVE_NET_IF_ARP_H=1 -DH
AVE_PCAP_NAMEDB_H=1 -DHAVE_STRING_H=1 -DHAVE_STRINGS_H=1 -DHAVE_CTYPE_H=1 -DHAVE_SYS_SOCKET_H=1 -DH
AVE_PATHS_H=1  -c rarpd.c -o rarpd.o
rarpd.c: In function `process_arp':
rarpd.c:341: structure has no member named `ar_sha'
rarpd.c:342: structure has no member named `ar_spa'
rarpd.c:343: structure has no member named `ar_tha'
rarpd.c:344: structure has no member named `ar_tpa'
rarpd.c: In function `main':
rarpd.c:456: warning: assignment makes pointer from integer without a cast
make: *** [rarpd.o] Error 1


any help, please??
thanks!