How To Use an UCS Server With Samba and Multiple Interfaces In Different LANs

How To Use an UCS Server With Samba and Multiple Interfaces In Different LANs

You have multiple LANs configured in your environment and you are looking for the best way to make UCS services (especially Samba) available to all your networks.

Things to Consider

Basically, accessing services relies on DNS name resolution.

Scenarios

All things in common between the follwing scenarios:

  • The server has multiple network interface cards (NICs)
  • Each of the NICs are connected to a different local network (LAN)
  • Access to the service is done by name, not by IP address

Scenario 1: All IPs have hostname entries

You have created DNS entries for all of your NICs IP addresses.

Issue

DNS replies for multiple identical entries in a “round-robin” manner. A client from network1 would get for the server name the server IP from network2. So instead of accessing the service directly the request would be routed. And the reply package would be send directly. Having an asynchronous route is possible but not recommended.

Scenario 2: Only one hostname entry for one IP address

The DNS server will always reply with the same IP address.

Issue

Similar to above but all clients except the ones from the LAN with the hostname matching the IP address will have direct access. All others will have asynchronous routing.

Scenario 3: Have unique DNS names for each interfac

Thus no asynchronous routing will happen.

Issue

Your clients need to be configured differently depending on the network they are currently connected to. For roaming users asynchronous routing would happen anyways.

Solution

Best do not attach the server’s interfaces to different LANs. Configure them as a bridge and connect them all to the same LAN. This will prevent asynchronous routing at all.