I am having problems with pam logins on a 2.4.21-sgi230r7 ia64 server.
I have a duplicate setup on an i386/i686 server running 2.4.24. It
doesn't appear that /etc/nsswitch.conf ever gets looked at on the sgi
(ia64)

Both machines have nss_ldap 189, pam_ldap 215.

Working i386 server:
[root@grid tmp]# strace -f su - aj8417 2>&1 | grep conf
open("/etc/nsswitch.conf", O_RDONLY) = 3
read(3, "#\n# /etc/nsswitch.conf\n#\n# An ex"..., 4096) = 1733
open("/etc/ldap.conf", O_RDONLY) = 3
read(3, "# @(#)$Id: ldap.conf,v 1.27 2003"..., 4096) = 4096
open("/etc/resolv.conf", O_RDONLY) = 3
open("/etc/host.conf", O_RDONLY) = 3
open("/etc/openldap/ldap.conf", O_RDONLY) = 3
open("/opt/nmi/lib/libglobus_gsi_sysconfig_gcc32.so.0", O_RDONLY) = 4
open("/etc/security/limits.conf", O_RDONLY) = 4
read(4, "# /etc/security/limits.conf\n#\n#E"..., 4096) = 1418
[pid 23636] open("/etc/nsswitch.conf", O_RDONLY) = 3
[pid 23636] read(3, "#\n# /etc/nsswitch.conf\n#\n# An ex"..., 4096) =
1733
[pid 23636] open("/etc/ldap.conf", O_RDONLY) = 3
[pid 23636] read(3, "# @(#)$Id: ldap.conf,v 1.27 2003"..., 4096) =
4096
[pid 23636] open("/etc/resolv.conf", O_RDONLY) = 3
[pid 23636] open("/etc/host.conf", O_RDONLY) = 3
[pid 23636] open("/etc/openldap/ldap.conf", O_RDONLY) = 3
[pid 23642] open("/etc/nsswitch.conf", O_RDONLY) = 3
[pid 23642] read(3, "#\n# /etc/nsswitch.conf\n#\n# An ex"..., 4096) =
1733
[pid 23642] open("/etc/ldap.conf", O_RDONLY) = 3
[pid 23642] read(3, "# @(#)$Id: ldap.conf,v 1.27 2003"..., 4096) =
4096
[pid 23642] open("/etc/resolv.conf", O_RDONLY) = 3
[pid 23642] open("/etc/host.conf", O_RDONLY) = 3
[pid 23642] open("/etc/openldap/ldap.conf", O_RDONLY) = 3
[pid 23636] stat64("/etc/sysconfig/i18n", {st_mode=S_IFREG|0644,
st_size=44, ...}) = 0
[pid 23636] stat64("/etc/sysconfig/i18n", {st_mode=S_IFREG|0644,
st_size=44, ...}) = 0
[pid 23636] open("/etc/sysconfig/i18n", O_RDONLY|O_LARGEFILE) = 4
[pid 23711] open("/etc/nsswitch.conf", O_RDONLY) = 3
[pid 23711] read(3, "#\n# /etc/nsswitch.conf\n#\n# An ex"..., 4096) =
1733
[pid 23713] open("/etc/nsswitch.conf", O_RDONLY) = 3
[pid 23713] read(3, "#\n# /etc/nsswitch.conf\n#\n# An ex"..., 4096) =
1733
[pid 23713] open("/etc/ldap.conf", O_RDONLY) = 3
[pid 23713] read(3, "# @(#)$Id: ldap.conf,v 1.27 2003"..., 4096) =
4096
[pid 23713] open("/etc/resolv.conf", O_RDONLY) = 3
[pid 23713] open("/etc/host.conf", O_RDONLY) = 3
[pid 23713] open("/etc/openldap/ldap.conf", O_RDONLY) = 3
[pid 23713] open("/opt/nmi/lib/libglobus_gsi_sysconfig_gcc32.so.0",
O_RDONLY) = 4
[pid 23717] open("/etc/nsswitch.conf", O_RDONLY) = 3
[pid 23717] read(3, "#\n# /etc/nsswitch.conf\n#\n# An ex"..., 4096) =
1733
exit
[root@grid tmp]#

Non-working ia64 server:
[root@dynamo pam.d]# strace -f su - aj8417 2>&1 | grep conf
[root@dynamo pam.d]#

Any help would be appreciated.