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  1. #1
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    Network but no internet connection.

    We have a small office network that I manage. There are 12 PC's running Windows 10 an RDC server (Server 2008R2) and 2 off DNS servers (Server 2012R2 and a 32bit Server 2003R2). The DHCP is controlled from the router which is a Netgear FVS 318.
    All the servers have historically been set static IP's within the DHCP range and set as such also in the router table. All the PC's except 2 have DCHP IP's. Various other hardware has static and/or reserved IP's and 2 printers have static IP's within the DHCP range.
    Until recently servers, PC's and hardware friends have all communicated on the intranet and as necessary also the internet.

    About 2 months ago one of the PC's lost connection with the internet although it continued connection internally on the intranet. A replacement PC was installed at the physical location and all returned to normal. Testing the PC including reloading windows (clean) has failed to return it to seeing the internet.

    More recently the same fate befell our primary DNS server. We do not use it for browsing but now it fails to send backups offsite plus a couple of other minor internet related functions.
    When the opportunity arose it was changed from static to DHCP and immediately picked up the internet. As soon as it was returned to static IP the connection was lost.

    Much is posted on the web about power settings and so forth for the LAN but these make no difference. The LAN has been disabled and tried with Microsoft and Realtek drivers but there is no change.
    I have tried IPCONFIG options of release, dnsflush, etc and also
    NETSH to reset WINSOCK etc. but am getting nowhere.

    I'd appreciate any suggestions.

  2. #2
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    You have a DNS server and use the router for DHCP? This is asking for trouble as the router will also provide DNS services.
    If the computers are in a domain you should never use the router for DHCP, the Domain Controller should always provide both DHCP and DNS.
    Personally I'd have your server set up with a static IP and let it provide DHCP and DNS.

    Please post details of the DHCP / DNS settings you currently use?

    cheers, Paul

  3. #3
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    We have a primary DNS server and a 'backup' the latter 2003r2 32bit.
    Would you suggest the 'backup' also be used for DHCP? My understanding was that if DNS servers were used in this arrangement that it was better to use the router for DHCP that way if either DNS were lost then licenses would still be issued. 2 x DHCP being effectively like to 2 tigers fighting and potentially causing conflicting IP's.

    I can down our network/servers today and 'play' with them so I'll try as suggested using DNS/DHCP on the primary server.

  4. #4
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    Hi Paul

    DHCP scope is 192.186.192.3 - 192.168.192.50
    Router is 192.168.192.1
    AP is 192.168.192.2
    DNS Pri is 192.168.192.44
    DNS Sec is 192.168.192.4
    RDC / TS Server 192.168.192.33
    Static IP Printers 192.168.192.11 and 192.168.192.8
    Static IP Workstation 192.168.192.25
    All other workstations are DHCP
    Kvm cards and other mobile devices are out of DHCP scope.
    All are on Subnet 255.255.255.0

    Regards

  5. #5
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    You have servers in your DHCP range, this is bad m'kay. Only workstations and possibly printers should be in the DHCP range. I usually reserve adresses at the bottom of the IP range for fixed devices and leave all others for DHCP to manage - reserve 1 to 20, DHCP range is then 21 to 254.
    You only need one DHCP and one DNS provider for a network that size.
    It is OK to use the router for both DNS and DHCP, but it limits your options slightly - DNS additions like servers are harder to add.

    DHCP / DNS has nothing to do with issuing licences. Which licenses are you talking about?

    How do you set the DNS for workstations? Have you modified the DHCP settings on the router? Auto configuration via DHCP is the best method.

    How have you configured your DNS to provide internet addresses?

    cheers, Paul

  6. #6
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    The servers listing in the DHCP scope is historical from pre server 2000 days. The IP's have not been changed and there has never been any adverse issues resulting. The 2 DNS servers exist because the newer 2012 was to take over from the older 2003 sever which was to be retired. Unfortunately the older server has a MySQL dBase that we have been unable to transfer so although it was demoted to Sec DNS it's role was never removed. In reality that has proved to be a 'blessing' following a major hardware failure of our RDC server which resulted in a temporary transfer of roles over the time it took to repair.
    Alpologies for typo error should have said leases not licenses.

    The DNS for workstations are for the main part DHCP asigned by the router (Netgear FVS318) some are reserved but not by need or current purpose and none are reporting issues.

    I'm not quite certain what you mean by "How have you configured your DNS to provide internet addresses?"

  7. #7
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    You have assigned DNS via DHCP so the router must have the DNS settings configured manually?
    On the PC that isn't happy is the DNS correct?
    If you ping google do you get an IP address from DNS?
    Are the network routes correct? Open a Command Prompt and type "route print". Post the output here if you are not sure.

    cheers, Paul

  8. #8
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    The router is configured manually and has IP 192.168.192.1

    On the server with the problem the settings are
    Fixed IP 192.168.192.44 also set on router
    Subnet 255.255.255.0
    Gateway 192.168.192.1

    On the workstation with the problem
    Obtain IP automatically
    Gateway 192.168.192.1

    Ping google.com returns "timed out"
    Ping known current google IP 216.58.213.110 returns "timed out"

    Ping 192.168.192.1 returns 4 off clear packets (zero loss)
    Ping netgear.<domain> returns IP and 4 clear packets (zero loss)


    PS Z:\> route print
    ================================================== =========================
    Interface List
    17...2c 56 dc 77 8b 4b ......Realtek PCIe GBE Family Controller
    1...........................Software Loopback Interface 1
    16...00 00 00 00 00 00 00 e0 Microsoft ISATAP Adapter
    ================================================== =========================

    IPv4 Route Table
    ================================================== =========================
    Active Routes:
    Network Destination Netmask Gateway Interface Metric
    0.0.0.0 0.0.0.0 192.168.192.1 192.168.192.44 266
    127.0.0.0 255.0.0.0 On-link 127.0.0.1 306
    127.0.0.1 255.255.255.255 On-link 127.0.0.1 306
    127.255.255.255 255.255.255.255 On-link 127.0.0.1 306
    192.168.192.0 255.255.255.0 On-link 192.168.192.44 266
    192.168.192.44 255.255.255.255 On-link 192.168.192.44 266
    192.168.192.255 255.255.255.255 On-link 192.168.192.44 266
    224.0.0.0 240.0.0.0 On-link 127.0.0.1 306
    224.0.0.0 240.0.0.0 On-link 192.168.192.44 266
    255.255.255.255 255.255.255.255 On-link 127.0.0.1 306
    255.255.255.255 255.255.255.255 On-link 192.168.192.44 266
    ================================================== =========================
    Persistent Routes:
    Network Address Netmask Gateway Address Metric
    0.0.0.0 0.0.0.0 192.168.192.1 Default
    ================================================== =========================

    IPv6 Route Table
    ================================================== =========================
    Active Routes:
    If Metric Network Destination Gateway
    1 306 ::1/128 On-link
    1 306 ff00::/8 On-link
    ================================================== =========================
    Persistent Routes:
    None
    PS Z:\>

    The route table appears the same as other servers/workstation without the problem. (Static IP's excepted)

  9. #9
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    A ping first performs a DNS lookup so the line of interest is: Pinging google.com [209.85.202.99] with 32 bytes of data
    This doesn't have a defined route so it will use the one for 0.0.0.0, which is the first one shown, via the router.
    To test that it is using that route, run "tracert google.com".
    The first 4 lines from my machine:
    Code:
    Tracing route to google.com [216.58.213.78]
    over a maximum of 30 hops:
    
      1     1 ms     1 ms     1 ms  bthub.home [192.168.1.254]
      2     *        *        *     Request timed out.
      3     *        7 ms     7 ms  31.55.186.197
      4     7 ms     7 ms     7 ms  31.55.186.196
      5     7 ms     7 ms     6 ms  195.99.127.42
    As you can see my router is the first point of contact.

    I can't see anything obviously wrong with your config, although having a persistent route set seems unnecessary and the metric of your first route seems long at 266, I would have expected 10 or 20.

    cheers, Paul

  10. #10
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    This is from OK workstation;
    Tracing route to google.com [216.58.213.78]
    over a maximum of 30 hops:

    1 1 ms 1 ms 1 ms netgear.broughton [192.168.192.1]
    2 * * * Request timed out.
    3 * 42 ms 28 ms 31.55.185.197
    4 35 ms 28 ms 27 ms 31.55.185.196
    5 27 ms 27 ms 27 ms core2-hu0-9-0-0.colindale.ukcore.bt.net [195.99.127.140]
    6 41 ms 38 ms 42 ms 62.172.103.19
    7 28 ms 37 ms 28 ms 109.159.253.67
    8 38 ms 28 ms 39 ms 64.233.174.87
    9 27 ms 27 ms 44 ms 216.239.57.115
    10 33 ms 41 ms 28 ms lhr25s01-in-f78.1e100.net [216.58.213.78]

    Trace complete.

    This is from server with problem;
    PS C:\ tracert google.com
    Unable to resolve target system name google.com
    PS C:\ tracert 216.58.213.78

    Tracing route to 216.58.213.78 over a maximum of 30 hops

    1 Transmit error: code 1231.

    Trace complete.

    --//--

    Metric is set to Auto

    --//--

    I have tried all I know and it ends the same. I have also tried a lot of the adaptor setting arrangements suggested on-line but to no avail.

    One thing I did note was that the IP asigned to a CrashPlan backup link showed the IP as 192.168.192.26:2242 for the connecting port. This link does not work and I've now removed it. I couldn't find this relationship anywhere but removing it made no difference anyway.

  11. #11
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    Assuming the DNS is correct (run IPCONFIG /ALL) then your IP stack is broken.
    This post may have a resolution.
    http://windowssecrets.com/forums/sho...s-from-NIC-GUI

    cheers, Paul

  12. The Following User Says Thank You to Paul T For This Useful Post:

    Duncan McDonald (2016-04-07)

  13. #12
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    I tried the following;
    deleting the reg entry as suggested
    as previously tried netsh int ip reset
    running M$ suggested EasyFix20140mini.diagcab
    i.e.

    Each did as required except the netsh cmd howeveer the M$ fix does the same.

    The TCIP protocol was replaced on startup however, the result is unchanged and the server still cannot access the internet.

    I have also gone back through the DNS settings and also DHCP and ipconfig /all returns - NB IPv6 has been turned on now

    Windows IP Configuration

    Host Name . . . . . . . . . . . . : Prime-Mover
    Primary Dns Suffix . . . . . . . : broughton
    Node Type . . . . . . . . . . . . : Hybrid
    IP Routing Enabled. . . . . . . . : No
    WINS Proxy Enabled. . . . . . . . : No
    DNS Suffix Search List. . . . . . : broughton

    Ethernet adapter Ethernet:

    Connection-specific DNS Suffix . : broughton
    Description . . . . . . . . . . . : Realtek PCIe GBE Family Controller
    Physical Address. . . . . . . . . : 2C-56-DC-77-8B-4B
    DHCP Enabled. . . . . . . . . . . : No
    Autoconfiguration Enabled . . . . : Yes
    Link-local IPv6 Address . . . . . : fe80::7c48:2ed2:7387:fc3f%17(Preferred)
    IPv4 Address. . . . . . . . . . . : 192.168.192.44(Preferred)
    Subnet Mask . . . . . . . . . . . : 255.255.255.0
    Default Gateway . . . . . . . . . : 192.168.192.1
    DHCPv6 IAID . . . . . . . . . . . : 405559004
    DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-1E-75-D3-F1-2C-56-DC-77-8B-4B
    DNS Servers . . . . . . . . . . . : 192.168.192.44
    192.168.192.4
    127.0.0.1
    NetBIOS over Tcpip. . . . . . . . : Enabled

    Tunnel adapter isatap.broughton:

    Media State . . . . . . . . . . . : Media disconnected
    Connection-specific DNS Suffix . : broughton
    Description . . . . . . . . . . . : Microsoft ISATAP Adapter
    Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
    DHCP Enabled. . . . . . . . . . . : No
    Autoconfiguration Enabled . . . . : Yes

  14. #13
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    Thumbs up

    Success!

    The server now connects to the internet. A lesson to be learned in looking at basics.

    Having assessed that there could not be a problem with the server setup it left only the router to be a block.
    Whilst the DHCP table was OK, with all workstations except one totally DHCP run and the firewall not filtering individual macs I checked the IP/mac binding table.
    There was corruption with several mac and IP not correctly associated, which was wrong is irrelevant since the either could have been incorrect in association to the other.
    The incorrect entries were deleted and correct values entered. Hey presto like magic the path was cleared to the internet.

    Thank you for all your help Paul.

  15. #14
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    I wouldn't call router table corruption "basics", but glad you got there.

    cheers, Paul

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