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Difficulty: HardIP Addressing and Network Configuration

A systems administrator is configuring a dual-homed backup server equipped with two network interface cards (NICs). NIC 1 connects to the corporate LAN (192.168.10.0/24192.168.10.0/24) with IP address 192.168.10.50192.168.10.50, subnet mask 255.255.255.0255.255.255.0, and default gateway 192.168.10.1192.168.10.1. NIC 2 connects directly to a dedicated local iSCSI storage network (10.0.50.0/2410.0.50.0/24) with IP address 10.0.50.2510.0.50.25, subnet mask 255.255.255.0255.255.255.0, and default gateway 10.0.50.110.0.50.1. While local LAN management access functions normally, outbound traffic destined for remote subnets experiences unpredictable routing drops. Which configuration change will resolve the routing issue while maintaining connectivity to both networks?

  1. Remove the default gateway address entry from the NIC 2 configuration.Answer
  2. B
    Reconfigure NIC 2 to auto-assign an APIPA address so iSCSI targets can be dynamically discovered without gateways.
  3. C
    Set the primary DNS server IP on NIC 1 to match the IP address of NIC 2 so DHCP leases update route targets.
  4. D
    Replace the router on the corporate LAN with an unmanaged Layer 2 switch to bridge the two IP subnets.

Answer

Removing the default gateway address from the secondary NIC (NIC 2) resolves the routing conflict while preserving communication across both network segments.
On a multihomed operating system, defining default gateways on multiple network adapters creates multiple default routes (0.0.0.0/00.0.0.0/0) with equal or competing metrics. This leads to asymmetric routing or packet loss when traffic destined for external networks is sent out of an adapter connected to a isolated segment. Since the iSCSI network is local (10.0.50.0/2410.0.50.0/24), host-to-storage traffic is routed directly via the connected subnet interface without requiring a default gateway. Removing the default gateway from the secondary adapter ensures all off-subnet traffic is predictably sent through the primary interface gateway.

Step-by-Step Solution

1
Analyze the network configuration of the multihomed server.
NIC 1 (192.168.10.50/24192.168.10.50/24) and NIC 2 (10.0.50.25/2410.0.50.25/24) both have default gateways defined (192.168.10.1192.168.10.1 and 10.0.50.110.0.50.1).
Having multiple default gateways on a single host creates competing default routes (0.0.0.0/00.0.0.0/0) in the local routing table.
2
Identify the purpose of each connected network segment.
NIC 1 provides access to the corporate LAN and remote subnets, whereas NIC 2 communicates strictly with local iSCSI storage targets on 10.0.50.0/2410.0.50.0/24.
Traffic to local subnets (10.0.50.0/2410.0.50.0/24) is handled by directly connected interface routes and does not require a gateway.
3
Determine the necessary TCP/IP configuration correction.
Clear the default gateway field on NIC 2.
Removing the secondary default gateway ensures all non-local outbound traffic flows exclusively through NIC 1's gateway (192.168.10.1192.168.10.1) without breaking local communication on 10.0.50.0/2410.0.50.0/24.

Key Concept

Multihomed Default Gateway Routing Constraints
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Topics

IP Addressing and Network Configuration

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