edutech4schools Posted March 1, 2016 Posted March 1, 2016 I have been getting all sorts of server (2008r2) errors so decided to run DCDIAG which lists lots of issues, although I am sure that fixing one will fix the others. The first error I am getting is Doing initial required tests Testing server: Default-First-Site-Name\???????-SRV01 Starting test: Connectivity * Active Directory LDAP Services Check The host d0b7784e-bb95-4ba9-b23b-d0c22cea8833._msdcs.???????.LAN could not be resolved to an IP address. Check the DNS server, DHCP, server name, etc. Got error while checking LDAP and RPC connectivity. Please check your firewall settings. ......................... ??????-SRV01 failed test Connectivity This is really starting to stress me out now, so I really hope someone can help.
edutech4schools Posted March 1, 2016 Author Posted March 1, 2016 Also in DNS in the name servers properties I am getting name server ip unknown
edutech4schools Posted March 1, 2016 Author Posted March 1, 2016 Also in DNS it has just come up with reverse lookup can not be contacted
Roberto Posted March 1, 2016 Posted March 1, 2016 * Active Directory LDAP Services Check The host d0b7784e-bb95-4ba9-b23b-d0c22cea8833._msdcs.???????.LAN Is that an absolute literal quote of the error message, question marks and all? It's possible for entries to get mashed in DNS. Stuff happens. I'm assuming here that you've checked the basics, that DNS for the domain is basically functional, that DNS *client* settings on the server are correct, etc. Assuming the _msdcs container exists in the AD DNS, this suggests that a DC's entry is missing from this container (or, more simply, the A record for the DC in question is missing). A simple fix that might work if that *is* the case, is to log on to the 'missing' dc and carry out the following steps from a command line: 1. ipconfig /flushdns 2. ipconfig /registerdns 3. net stop netlogon 4. net start netlogon 1
edutech4schools Posted March 1, 2016 Author Posted March 1, 2016 Hello @Roberto I was just about to do as you suggested but now DNS will not even load. error is 'The server is unavailable. As a precaution I have pointed this servers network adapter at our other DC, as the main DNS server, and pointed all clients at our other DNS server using DHCP. The failing server holds all the roles but also all the network shares, DHCP, printers, SQL server etc (this is a primary school) Really hope someone has an idea for getting DNS back up on this server soon.
edutech4schools Posted March 1, 2016 Author Posted March 1, 2016 Should I move or seize the roles onto the other DC?
Roberto Posted March 1, 2016 Posted March 1, 2016 ok pointing it to other DCs for its DNS client stuff is a good start. Does the DNS server service start? Errors in the event log? I would not be quick to seize roles or anything like that just yet.
rrrrr Posted March 1, 2016 Posted March 1, 2016 Take it you have temporarily disabled windows firewall on dc's and retried to see if this is the cause?
edutech4schools Posted March 1, 2016 Author Posted March 1, 2016 Take it you have temporarily disabled windows firewall on dc's and retried to see if this is the cause? The servers do not have firewall enabled as requested by LA. Does the DNS server service start? Errors in the event log? The DNS service says it is started
edutech4schools Posted March 1, 2016 Author Posted March 1, 2016 errors in the event log? oddly no errors under DNS in event log. For today it has, dns has started and DNS has finished background loading of zones.
rrrrr Posted March 1, 2016 Posted March 1, 2016 Are you getting similar issues running dcdiag on other dc's?
edutech4schools Posted March 1, 2016 Author Posted March 1, 2016 I have also found a bunch of Netlogon errors event 5774 netlogon but they stopped reporting any error about 6 hours ago.
Roberto Posted March 1, 2016 Posted March 1, 2016 ok, have you read the following articles? Event ID 5774 | Ace Fekay https://support.microsoft.com/en-us/kb/284963 When did these changes start? Is the problematic DC multi-homed? Looking at the DNS server config on the other DC, do the DNS entries for the faulty one look sane?
edutech4schools Posted March 1, 2016 Author Posted March 1, 2016 Are you getting similar issues running dcdiag on other dc's? When I ran dcdiag earlier on the working server it was giving the same error but about the non working server. I will run it again tomorrow and post back.
edutech4schools Posted March 2, 2016 Author Posted March 2, 2016 ok, have you read the following articles? Event ID 5774 | Ace Fekay https://support.microsoft.com/en-us/kb/284963 When did these changes start? Is the problematic DC multi-homed? Looking at the DNS server config on the other DC, do the DNS entries for the faulty one look sane? just working through these. Our Working DNS has dynamic zones set to secure - is this correct?? It is AD integrated.
edutech4schools Posted March 2, 2016 Author Posted March 2, 2016 OK I have worked through both those links. A couple of the items I can't do as DNS does not even open on the faulty server but I did everything else. Still can't access DNS. When did these changes start? Looks like it has been an issue for a while, but I have only recently realized as I only visit the school for a morning every other week. Is the problematic DC multi-homed? No Looking at the DNS server config on the other DC, do the DNS entries for the faulty one look sane? They all look good to me but I am no DNS wizard. All IP's look correct and it even lists the faulty server in DNS/properties/name servers as being OK.
edutech4schools Posted March 2, 2016 Author Posted March 2, 2016 Are you getting similar issues running dcdiag on other dc's? Which switches would you advice I use to run DCDIAG??? When I simply run just DCDIAG on the working server I am now only getting one error. Starting test: DFSREvent There are warning or error events within the last 24 hours after sysvol has been shared. Failing SYSVOL replication problems may cause Group Policy problems DC-02 failed test DFSREvent
rrrrr Posted March 3, 2016 Posted March 3, 2016 Anyone got any advice? Have you checked repadmin /showrepl /all /verbose? Looking like it might be replication issue
edutech4schools Posted March 3, 2016 Author Posted March 3, 2016 Just found out I can access DNS for DC1 from DNS console on DC2.
edutech4schools Posted March 3, 2016 Author Posted March 3, 2016 repadmin /showrepl /all /verbose Seems to pass all, nothing jumps out as being wrong
rrrrr Posted March 3, 2016 Posted March 3, 2016 Seems to pass all, nothing jumps out as being wrong Tested on all dc's?. Are they all global catalog servers? If not, is the infrastructure master fsmo role on a gc server?
Roberto Posted March 4, 2016 Posted March 4, 2016 Which switches would you advice I use to run DCDIAG??? When I simply run just DCDIAG on the working server I am now only getting one error. Is the sysvol share available? Can you connect to \\fully.qualified.domain.name\sysvol ? Can you connect to \\first server's name\sysvol and \\second server's name\sysvol?
edutech4schools Posted March 4, 2016 Author Posted March 4, 2016 repadmin /showrepl /all /verbose Tested on all dc's?. Are they all global catalog servers? If not, is the infrastructure master fsmo role on a gc server? Just tested on DC2 all looks good, everything passed. Yes they are both GC servers Roles are on the the faulty server DC1 s the sysvol share available? Can you connect to \\fully.qualified.domain.name\sysvol ? Can you connect to \\first server's name\sysvol and \\second server's name\sysvol? This all works from both DCs
Roberto Posted March 4, 2016 Posted March 4, 2016 This is a tricky one. If this was _just_ a DC then I'd suggest seizing fsmo roles and a quick demote / promote cycle to give it a kick up the backside but that isn't an option here really. Speaking of FSMO options, are they all showing as available/sensible in ADUC and AD sites and services?
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