I found out that the nss_ldap queries works with getent hosts xyz but not with ping xyz
ping (and e.g. traceroute) hangs somewhere within ldap_init ( libnss_ldap with debugging stops after: "nss_ldap: ==> ldap_init" ) and futex ( strace stops at "futex(0x375a8c, FUTEX_WAIT, 2, NULL" )
This is the same for known and unknown hosts.
Other programs work just fine: telnet rsh arping ssh ... (but ssh outputs a warning "socket: Address family not supported by protocol" )
regards, Herbert Gasiorowski http://www.mathematik.uni-marburg.de/~gasi/