Install problem

hi, i got this error while compiling PHP 5.3.10 on Redhat ES 4 lxml2 -lz -lm -lxml2 -lz -lm -lxml2 -lz -lm -lcrypt -lxml2 -lz -lm -lxml2 -lz -lm -lxml2 -lz -lm -lcrypt -o sapi/cli/php ext/standard/.libs/dns.o(.text+0x3c7): In function `zif_dns_check_record': /usr/local/src/php-5.3.10/ext/standard/dns.c:403: undefined reference to `__res_nsearch' ext/standard/.libs/dns.o(.text+0x5db): In function `php_parserr': /usr/local/src/php-5.3.10/ext/standard/dns.c:428: undefined reference to `__dn_expand' ext/standard/.libs/dns.o(.text+0x74e):/usr/local/src/php-5.3.10/ext/standard/dns.c:662: undefined reference to `__dn_expand' ext/standard/.libs/dns.o(.text+0x846):/usr/local/src/php-5.3.10/ext/standard/dns.c:523: undefined reference to `__dn_expand' ext/standard/.libs/dns.o(.text+0x895):/usr/local/src/php-5.3.10/ext/standard/dns.c:529: undefined reference to `__dn_expand' ext/standard/.libs/dns.o(.text+0xceb):/usr/local/src/php-5.3.10/ext/standard/dns.c:684: undefined reference to `__dn_expand' ext/standard/.libs/dns.o(.text+0x107a):/usr/local/src/php-5.3.10/ext/standard/dns.c:646: more undefined references to `__dn_expand' follow ext/standard/.libs/dns.o(.text+0x135a): In function `zif_dns_get_record': /usr/local/src/php-5.3.10/ext/standard/dns.c:820: undefined reference to `__res_nsearch' ext/standard/.libs/dns.o(.text+0x13cf):/usr/local/src/php-5.3.10/ext/standard/dns.c:837: undefined reference to `__dn_skipname' ext/standard/.libs/dns.o(.text+0x18e9): In function `zif_dns_get_mx': /usr/local/src/php-5.3.10/ext/standard/dns.c:937: undefined reference to `__res_nsearch' ext/standard/.libs/dns.o(.text+0x192a):/usr/local/src/php-5.3.10/ext/standard/dns.c:948: undefined reference to `__dn_skipname' ext/standard/.libs/dns.o(.text+0x195e):/usr/local/src/php-5.3.10/ext/standard/dns.c:955: undefined reference to `__dn_skipname' ext/standard/.libs/dns.o(.text+0x1a2a):/usr/local/src/php-5.3.10/ext/standard/dns.c:968: undefined reference to `__dn_expand' collect2: ld returned 1 exit status make: *** [sapi/cli/php] Error 1 am i missing something? package? tia,