LinuxQuestions.org - samba server joining Active directory server 2008 error

i try to join samba server to active director server 2008 r2.i set every thing in server server smb configuration and kerberos configuration done
/etc/samba/smb.conf/

[global]

# define the netbios name of the domain

workgroup = CAMPUS

# define the pptp server netbios name

netbios name = server

# define the AD domain name

realm = campus.local

# server description

server string = pptpd Server

# printer stuff

printcap name = /etc/printcap

load printers = no

cups options = raw

# log file stuff

log file = /var/log/samba/%m.log

max log size = 50

# must set to ads

security = ads

# address of domain controller

password server = x.x.x.x

# enable encrypt passwords

encrypt passwords = yes

# default setting

socket options = TCP_NODELAY SO_RCVBUF=8192 SO_SNDBUF=8192

# not to be a master browser

domain master = no

preferred master = no

# address of the WINS server

wins server = x.x.x.x

dns proxy = no

require this line to join the domain

client use spnego = yes

# winbind stuff

idmap uid = 50001-550000

idmap gid = 50001-550000

;winbind separator = +

winbind nested groups = Yes

winbind enum users=yes

winbind enum groups=yes

template shell = /bin/false

winbind use default domain = yes

nt pipe support = no

#smb ports=139

/etc/krb5.conf
[logging]
default = FILE:/var/log/krb5libs.log
kdc = FILE:/var/log/krb5kdc.log
admin_server = FILE:/var/log/kadmind.log

[libdefaults]
default_realm = campus.local
dns_lookup_realm = true
dns_lookup_kdc = true
ticket_lifetime = 24h
forwardable = yes

[realms]
campus.local = {
kdc = campus.local:88
admin_server = campus.local:749
default_domain = campus.local
}

[domain_realm]
.campus.local = campus.local
campus.local = campus.local

[kdc]
profile = /var/kerberos/krb5kdc/kdc.conf

[appdefaults]
pam = {
debug = false
ticket_lifetime = 36000
renew_lifetime = 36000
forwardable = true
krb4_convert = false
}

when i try to joing following output shown
net ads join -U Administrator@campus.local -d 5

libnet_JoinCtx: struct libnet_JoinCtx
in: struct libnet_JoinCtx
dc_name : NULL
machine_name : 'SERVER'
domain_name : *
domain_name : 'campus.local'
account_ou : NULL
admin_account : 'Administrator@campus.local'
machine_password : NULL
join_flags : 0x00000023 (35)
0: WKSSVC_JOIN_FLAGS_IGNORE_UNSUPPORTED_FLAGS
0: WKSSVC_JOIN_FLAGS_JOIN_WITH_NEW_NAME
0: WKSSVC_JOIN_FLAGS_JOIN_DC_ACCOUNT
0: WKSSVC_JOIN_FLAGS_DEFER_SPN
0: WKSSVC_JOIN_FLAGS_MACHINE_PWD_PASSED
0: WKSSVC_JOIN_FLAGS_JOIN_UNSECURE
1: WKSSVC_JOIN_FLAGS_DOMAIN_JOIN_IF_JOINED
0: WKSSVC_JOIN_FLAGS_WIN9X_UPGRADE
0: WKSSVC_JOIN_FLAGS_ACCOUNT_DELETE
1: WKSSVC_JOIN_FLAGS_ACCOUNT_CREATE
1: WKSSVC_JOIN_FLAGS_JOIN_TYPE
os_version : NULL
os_name : NULL
create_upn : 0x00 (0)
upn : NULL
modify_config : 0x00 (0)
ads : NULL
debug : 0x01 (1)
use_kerberos : 0x00 (0)
secure_channel_type : SEC_CHAN_WKSTA (2)
interpret_string_addr_internal: getaddrinfo failed for name campus.local [Name or service not known]
resolve_lmhosts: Attempting lmhosts lookup for name campus.local<0x1c>
resolve_lmhosts: Attempting lmhosts lookup for name campus.local<0x1c>
resolve_wins: Attempting wins lookup for name campus.local<0x1c>
resolve_wins: using WINS server 10.3.20.70 and tag '*'
name_resolve_bcast: Attempting broadcast lookup for name campus.local<0x1c>
libnet_Join:
libnet_JoinCtx: struct libnet_JoinCtx
out: struct libnet_JoinCtx
account_name : NULL
netbios_domain_name : NULL
dns_domain_name : NULL
forest_name : NULL
dn : NULL
domain_sid : NULL
domain_sid : (NULL SID)
modified_config : 0x00 (0)
error_string : 'failed to find DC for domain campus.local'
domain_is_ad : 0x00 (0)
result : WERR_DCNOTFOUND
libnet_Join:
libnet_JoinCtx: struct libnet_JoinCtx
in: struct libnet_JoinCtx
dc_name : NULL
machine_name : 'SERVER'
domain_name : *
domain_name : 'CAMPUS'
account_ou : NULL
admin_account : 'Administrator@campus.local'
machine_password : NULL
join_flags : 0x00000023 (35)
0: WKSSVC_JOIN_FLAGS_IGNORE_UNSUPPORTED_FLAGS
0: WKSSVC_JOIN_FLAGS_JOIN_WITH_NEW_NAME
0: WKSSVC_JOIN_FLAGS_JOIN_DC_ACCOUNT
0: WKSSVC_JOIN_FLAGS_DEFER_SPN
0: WKSSVC_JOIN_FLAGS_MACHINE_PWD_PASSED
0: WKSSVC_JOIN_FLAGS_JOIN_UNSECURE
1: WKSSVC_JOIN_FLAGS_DOMAIN_JOIN_IF_JOINED
0: WKSSVC_JOIN_FLAGS_WIN9X_UPGRADE
0: WKSSVC_JOIN_FLAGS_ACCOUNT_DELETE
1: WKSSVC_JOIN_FLAGS_ACCOUNT_CREATE
1: WKSSVC_JOIN_FLAGS_JOIN_TYPE
os_version : NULL
os_name : NULL
create_upn : 0x00 (0)
upn : NULL
modify_config : 0x00 (0)
ads : NULL
debug : 0x01 (1)
use_kerberos : 0x00 (0)
secure_channel_type : SEC_CHAN_WKSTA (2)
ads_dns_lookup_srv: Failed to resolve _ldap._tcp.Default-First-Site-Name._sites.dc._msdcs.CAMPUS (Success)
ads_dns_lookup_srv: Failed to send DNS query (NT_STATUS_UNSUCCESSFUL)
ads_dns_lookup_srv: Failed to resolve _ldap._tcp.dc._msdcs.CAMPUS (Success)
ads_dns_lookup_srv: Failed to send DNS query (NT_STATUS_UNSUCCESSFUL)
resolve_lmhosts: Attempting lmhosts lookup for name CAMPUS<0x1c>
resolve_lmhosts: Attempting lmhosts lookup for name CAMPUS<0x1c>
resolve_wins: Attempting wins lookup for name CAMPUS<0x1c>
resolve_wins: using WINS server x.x.x.x and tag '*'
name_resolve_bcast: Attempting broadcast lookup for name CAMPUS<0x1c>
libnet_Join:
libnet_JoinCtx: struct libnet_JoinCtx
out: struct libnet_JoinCtx
account_name : NULL
netbios_domain_name : NULL
dns_domain_name : NULL
forest_name : NULL
dn : NULL
domain_sid : NULL
domain_sid : (NULL SID)
modified_config : 0x00 (0)
error_string : 'failed to find DC for domain CAMPUS'
domain_is_ad : 0x00 (0)
result : WERR_DCNOTFOUND
Failed to join domain: failed to find DC for domain CAMPUS
return code = -1

Please help to sort out this problem