To me this seems very bizarre. It might be more of a NETWORKING question than an OPENVPN question.
New Lenovo ThinkPads (X1 Carbons) have wireless and a USB-connected wired Ethernet NIC dongle.
What I noticed:
I could probably work around this somehow, but I'd like to know why this device would have DNS resolution issues. I've cleared the cache, restarted, etc. One way I'm able to fix it is to go into the device settings of the USB Ethernet and turn ON, apply, and turn OFF again, the "ARP OFFLOAD" feature on the advanced adapter settings. Although this works, it's not a practical option for our users. The wireless adapter doesn't even have this feature listed in its settings, so I don't understand why this would be an issue if its disabled by default. According to the description of ARP Offload, it shouldn't have anything to do with NS resolution.
Settings list on the adapter:
Why would one Ethernet adapter be confused about the proper IP address of a particular destination?
Mailserver.mydomain.com has both an internal and external address, but only the LAN or VPN is allowed for authentication.
Is it just a faulty device? If it was faulty, then why does it work perfectly fine for all other resources, or from within the LAN. Hmm.
I look forward to your responses. Thanks, everyone.
Ron
New Lenovo ThinkPads (X1 Carbons) have wireless and a USB-connected wired Ethernet NIC dongle.
- Over wireless, VPN connects and all network resources connect and Outlook connects to Exchange just fine.
- Over wired, VPN connects and all network resources connect, but Exchange does not.
What I noticed:
- When performing an NSLOOKUP over WIRELESS VPN connection, it resolves to the proper internal address of the server, internal to the LAN.
- When performing an NSLOOKUP over WIRED VPN connection, it resolves to the externally-facing IP address of the Exchange server. This is most likely where the problem lies.
I could probably work around this somehow, but I'd like to know why this device would have DNS resolution issues. I've cleared the cache, restarted, etc. One way I'm able to fix it is to go into the device settings of the USB Ethernet and turn ON, apply, and turn OFF again, the "ARP OFFLOAD" feature on the advanced adapter settings. Although this works, it's not a practical option for our users. The wireless adapter doesn't even have this feature listed in its settings, so I don't understand why this would be an issue if its disabled by default. According to the description of ARP Offload, it shouldn't have anything to do with NS resolution.
Settings list on the adapter:
- ARP Offload
- AutoDetach
- Connection Type
- Flow Control
- IPv4 Checksum Offload
- Mask WakeUp Event Timer
- NetworkAddress
- NS offload
- QoS Packet Tagging
- TCP Checksum Offload (IPv4)
- TCP Checksum Offload (IPv6)
- UDP Checksum Offload (IPv4)
- UDP Checksum Offload (IPv6)
- VLAN ID
- Wake UP
- Wake-up Frame Type
- WOL Link Speed
Why would one Ethernet adapter be confused about the proper IP address of a particular destination?
Mailserver.mydomain.com has both an internal and external address, but only the LAN or VPN is allowed for authentication.
Is it just a faulty device? If it was faulty, then why does it work perfectly fine for all other resources, or from within the LAN. Hmm.
I look forward to your responses. Thanks, everyone.
Ron