Windows Server 2008 R2 drops packets
I seem to be having strange problems with my WS2008R2 Active Directory + DNS + DHCP + NAT configuration. It look to be some sort of an issue between DNS, NAT and LDAP.
The first consequence is some sort of packet dropping problem. Every once in a while, the server (acting as default gateway) will drop packets and command will return 'Destination host unreachable'. I have yet to figure out the cause. This seems unrelated to DNS.
C:\Users\Administrator>ping serverfault.com
Pinging serverfault.com [64.34.119.12] with 32 bytes of data:
Reply from 10.0.0.1: Destination host unreachable.
Reply from 64.34.119.12: bytes=32 time=113ms TTL=49
Request timed out.
Reply from 64.34.119.12: bytes=32 time=113ms TTL=49
C:\Users\Administrator>ping 74.125.79.105
Pinging 74.125.79.105 with 32 bytes of data:
Reply from 10.0.0.1: Destination host unreachable.
Reply from 74.125.79.105: bytes=32 time=39ms TTL=49
Reply from 74.125.79.105: bytes=32 time=37ms TTL=49
C:\Users\Administrator>ping 74.125.79.105
Pinging 74.125.79.105 with 32 bytes of data:
Reply from 74.125.79.105: bytes=32 time=36ms TTL=49
Reply from 74.125.79.105: bytes=32 time=36ms TTL=49
So the DNS resolves fine ... but then sometimes 10.0.0.1 drops packets .. just because? Happens intermittently. This was a test done on the server itself, but the clients exhibit pretty much the same behavior, except even DNS fails with them sometimes.
C:\Users\[user]>ping google.com
Ping request could not find host google.com. Please check the name and try again.
C:\Users\[user]>ping google.com
Pinging google.com [74.125.79.105] with 32 bytes of data:
Request timed out.
Reply from 74.125.79.105: bytes=32 time=37ms TTL=49
Reply from 74.125.79.105: bytes=32 time=36ms TTL=49
This will cause HTTP 404 errors, applications complaining about no internet connection, complaining about servers being offline, etc.
It's also reporting, for example
_ldap._tcp.Default-First-Site-Name._sites.[server].ad.[domain].net
No such name
Any help or tips would be very appreciated. :)
Update: Some server info.
C:\Users\Administrator>ipconfig /all
Windows IP Configuration
Host Name . . . . . . . . . . . . : [server]
Primary Dns Suffix . . . . . . . : ad.[domain].net
Node Type . . . . . . . . . . . . : Mixed
IP Routing Enabled. . . . . . . . : Yes
WINS Proxy Enabled. . . . . . . . : No
DNS Suffix Search List. . . . . . : ad.[domain].net
PPP adapter RAS (Dial In) Interface:
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : RAS (Dial In) Interface
Physical Address. . . . . . . . . :
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes
IPv4 Address. . . . . . . . . . . : 10.0.0.12(Preferred)
Subnet Mask . . . . . . . . . . . : 255.255.255.255
Default Gateway . . . . . . . . . :
NetBIOS over Tcpip. . . . . . . . : Enabled
Wireless LAN adapter Wireless Network Connection:
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Linksys WMP600N Wireless-N PCI Adapter wi
th Dual-Band
Physical Address. . . . . . . . . : 00-25-9C-FF-C1-FC
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes
IPv4 Address. . . . . . . . . . . : 192.168.1.100(Preferred)
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . . . . : 192.168.1.1
DNS Servers . . . . . . . . . . . : 10.0.0.1
127.0.0.1
NetBIOS over Tcpip. . . . . . . . : Enabled
Ethernet adapter Local Area Connection:
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Realtek RTL8168C(P)/8111C(P) Family PCI-E
Gigabit Ethernet NIC (NDIS 6.20)
Physical Address. . . . . . . . . : 00-19-66-88-6A-1F
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes
IPv4 Address. . . . . . . . . . . : 10.0.0.1(Preferred)
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . . . . : 0.0.0.0
DNS Servers . . . . . . . . . . . : 10.0.0.1
127.0.0.1
NetBIOS over Tcpip. . . . . . . . : Enabled
Tunnel adapter isatap.{B84CD253-70D3-49E5-88F9-102C6B7FCEC0}:
Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Microsoft ISATAP Adapter
Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes
Tunnel adapter Local Area Connection* 11:
Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Teredo Tunneling Pseudo-Interface
Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes
Tunnel adapter isatap.{D7DFBDDF-7295-43E8-AAD4-4910D79202A9}:
Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Microsoft ISATAP Adapter #2
Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes
Tunnel adapter isatap.{6E06F030-7526-11D2-BAF4-00600815A4BD}:
Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Microsoft ISATAP Adapter #3
Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes
C:\Users\Administrator>route print
===========================================================================
Interface List
26...........................RAS (Dial In) Interface
15...00 25 9c ff c1 fc ......Linksys WMP600N Wireless-N PCI Adapter with Dual-Band
11...00 19 66 88 6a 1f ......Realtek RTL8168C(P)/8111C(P) Family PCI-E GigabitEthernet NIC (NDIS 6.20)
1...........................Software Loopback Interface 1
12...00 00 00 00 00 00 00 e0 Microsoft ISATAP Adapter
13...00 00 00 00 00 00 00 e0 Teredo Tunneling Pseudo-Interface
14...00 00 00 00 00 00 00 e0 Microsoft ISATAP Adapter #2
16...00 00 00 00 00 00 00 e0 Microsoft ISATAP Adapter #3
===========================================================================
IPv4 Route Table
===========================================================================
Active Routes:
Network Destination Netmask Gateway Interface Metric
0.0.0.0 0.0.0.0 On-link 10.0.0.1 266
0.0.0.0 0.0.0.0 192.168.1.1 192.168.1.100 276
10.0.0.0 255.255.255.0 On-link 10.0.0.1 266
10.0.0.1 255.255.255.255 On-link 10.0.0.1 11
10.0.0.12 255.255.255.255 On-link 10.0.0.12 306
10.0.0.255 255.255.255.255 On-link 10.0.0.1 266
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
192.168.1.0 255.255.255.0 On-link 192.168.1.100 276
192.168.1.100 255.255.255.255 On-link 192.168.1.100 276
192.168.1.255 255.255.255.255 On-link 192.168.1.100 276
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 10.0.0.1 266
224.0.0.0 240.0.0.0 On-link 192.168.1.100 276
224.0.0.0 240.0.0.0 On-link 10.0.0.12 306
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 10.0.0.1 266
255.255.255.255 255.255.255.255 On-link 192.168.1.100 276
255.255.255.255 255.255.255.255 On-link 10.0.0.12 306
===========================================================================
Persistent Routes:
Network Address Netmask Gateway Address Metric
0.0.0.0 0.0.0.0 192.168.1.1 Default
===========================================================================
IPv6 Route Table
===========================================================================
Active Routes:
If Metric Network Destination Gateway
1 51 ::1/128 On-link
1 306 ff00::/8 On-link
===========================================================================
Persistent Routes:
None
The routing shows two gateways, both are used for external connections (network destination 0.0.0.0). If one is not responding then the other one is used. That's why some random packets get dropped. Try to remove the default gateway from your wired interface (10.0.0.1), this way the routing should always use the other gateway. Otherwise, you could check the route from the client to 0.0.0.0 and the dns servers on the client.