problems after compiling new kernel

[Pollywog <pollywog@shadypond.com>]

After compiling kernel 2.2.10 and trying to install new software, I got:

make  all-recursive
make[1]: Entering directory `/home/pollywog/ksnuffle-0.2'
Making all in libpcap-0.4
make[2]: Entering directory `/home/pollywog/ksnuffle-0.2/libpcap-0.4'
gcc -g  -I.  -Ilinux-include -DHAVE_MALLOC_H=1 -DHAVE_ETHER_HOSTTON=1
-DHAVE_STRERROR=1 -DHAVE_NET_IF_ARP_H=1  -c ./pcap-linux.c
./pcap-linux.c:31: net/if.h: No such file or directory
./pcap-linux.c:33: net/if_arp.h: No such file or directory
make[2]: *** [pcap-linux.o] Error 1


Why does this happen?  Am I doing something wrong?  It seems I frequently
"lose" if.h

--
Andrew