I have a server that has been running without issues for over 2 years, but in the last couple of days I have been having one hell of a time with winbind. For some reason it keeps hanging up which prevents my users from authenticating and also slows authentication for local users (not sure what is causing this).

Here is a snippet from the "log.wb-DOMAIN" file about the time that the hang occured:
Code:
2007/10/18 11:50:30, 1] nsswitch/winbindd_ads.c:query_user(474)
  query_user(sid=S-1-5-21-3238820900-141106115-3181249035-7517): Not found
[2007/10/18 11:50:30, 1] nsswitch/winbindd_user.c:winbindd_dual_userinfo(152)
  error getting user info for sid S-1-5-21-3238820900-141106115-3181249035-7517
[2007/10/18 12:11:16, 1] nsswitch/winbindd_ads.c:query_user(474)
  query_user(sid=S-1-5-21-3238820900-141106115-3181249035-7517): Not found
[2007/10/18 12:11:16, 1] nsswitch/winbindd_user.c:winbindd_dual_userinfo(152)
  error getting user info for sid S-1-5-21-3238820900-141106115-3181249035-7517
Here is a snippet of the "log.winbindd" file around the same time:
Code:
[2007/10/18 11:52:13, 1] libads/ldap_utils.c:ads_do_search_retry_internal(115)
  ads reopen failed after error Timed out
[2007/10/18 11:52:13, 1] nsswitch/winbindd_ads.c:query_user_list(180)
  query_user_list ads_search: Timed out
[2007/10/18 11:52:58, 1] libads/ldap_utils.c:ads_do_search_retry_internal(115)
  ads reopen failed after error Timed out
[2007/10/18 11:52:58, 1] nsswitch/winbindd_ads.c:query_user_list(180)
  query_user_list ads_search: Timed out
[2007/10/18 11:53:44, 1] libads/ldap_utils.c:ads_do_search_retry_internal(115)
  ads reopen failed after error Time limit exceeded
[2007/10/18 11:53:44, 1] nsswitch/winbindd_ads.c:query_user_list(180)
  query_user_list ads_search: Time limit exceeded
[2007/10/18 11:54:30, 1] libads/ldap_utils.c:ads_do_search_retry_internal(115)
  ads reopen failed after error Timed out
[2007/10/18 11:54:30, 1] nsswitch/winbindd_ads.c:query_user_list(180)
  query_user_list ads_search: Timed out
[2007/10/18 11:55:15, 1] libads/ldap_utils.c:ads_do_search_retry_internal(115)
  ads reopen failed after error Timed out
[2007/10/18 11:55:15, 1] nsswitch/winbindd_ads.c:query_user_list(180)
  query_user_list ads_search: Timed out
[2007/10/18 11:56:00, 1] libads/ldap_utils.c:ads_do_search_retry_internal(115)
  ads reopen failed after error Timed out
[2007/10/18 11:56:00, 1] nsswitch/winbindd_ads.c:query_user_list(180)
  query_user_list ads_search: Timed out
[2007/10/18 11:56:42, 1] nsswitch/idmap.c:idmap_init(365)
  Initializing idmap domains
[2007/10/18 11:57:40, 1] libads/ldap_utils.c:ads_do_search_retry_internal(115)
  ads reopen failed after error Timed out
[2007/10/18 11:57:40, 1] nsswitch/winbindd_ads.c:query_user_list(180)
  query_user_list ads_search: Timed out
[2007/10/18 11:57:40, 0] lib/util_sock.c:write_data(564)
  write_data: write failure. Error = Connection reset by peer
[2007/10/18 11:57:40, 0] libsmb/clientgen.c:write_socket(159)
  write_socket: Error writing 39 bytes to socket 37: ERRNO = Connection reset by peer
[2007/10/18 11:57:40, 0] libsmb/clientgen.c:cli_send_smb(189)
  Error writing 39 bytes to client. -1 (Connection reset by peer)
[2007/10/18 11:58:31, 1] libads/ldap_utils.c:ads_do_search_retry_internal(115)
  ads reopen failed after error Timed out
[2007/10/18 11:58:31, 1] nsswitch/winbindd_ads.c:query_user_list(180)
  query_user_list ads_search: Timed out
[2007/10/18 11:59:18, 1] libads/ldap_utils.c:ads_do_search_retry_internal(115)
  ads reopen failed after error Timed out
[2007/10/18 11:59:18, 1] nsswitch/winbindd_ads.c:query_user_list(180)
  query_user_list ads_search: Timed out
[2007/10/18 12:00:05, 1] libads/ldap_utils.c:ads_do_search_retry_internal(115)
  ads reopen failed after error Timed out
[2007/10/18 12:00:05, 1] nsswitch/winbindd_ads.c:query_user_list(180)
  query_user_list ads_search: Timed out
[2007/10/18 12:00:52, 1] libads/ldap_utils.c:ads_do_search_retry_internal(115)
  ads reopen failed after error Timed out
[2007/10/18 12:00:52, 1] nsswitch/winbindd_ads.c:query_user_list(180)
  query_user_list ads_search: Timed out
[2007/10/18 12:01:39, 1] libads/ldap_utils.c:ads_do_search_retry_internal(115)
  ads reopen failed after error Timed out
[2007/10/18 12:01:39, 1] nsswitch/winbindd_ads.c:query_user_list(180)
  query_user_list ads_search: Timed out
[2007/10/18 12:02:36, 1] libads/ldap_utils.c:ads_do_search_retry_internal(115)
  ads reopen failed after error Timed out
[2007/10/18 12:02:36, 1] nsswitch/winbindd_ads.c:query_user_list(180)
  query_user_list ads_search: Timed out
[2007/10/18 12:02:36, 0] lib/util_sock.c:write_data(564)
  write_data: write failure. Error = Connection reset by peer
[2007/10/18 12:02:36, 0] libsmb/clientgen.c:write_socket(159)
  write_socket: Error writing 39 bytes to socket 39: ERRNO = Connection reset by peer
[2007/10/18 12:02:36, 0] libsmb/clientgen.c:cli_send_smb(189)
  Error writing 39 bytes to client. -1 (Connection reset by peer)
From what I can tell by looking at these logs, it appears that winbind is just losing the connecting and hanging up. If I restart winbind when the hang occurs, everything returns to normal. I have contacted our IT department (note that this is a CAD server controlled by engineering) and they said that they don't see any problems on their end. I have also tried using 6 different domain controllers within our company to see if it helped, but I still have the hanging issues which leads me to believe we either have a networking issue or winbind is just being a royal pain in the ass.

Does anyone have any advice on this issue?