You want to configure a reth interface.

The correct answers are B and C . A redundant Ethernet interface, or reth , is a logical interface used in an SRX chassis cluster to provide interface redundancy across node0 and node1. Juniper states that a reth interface must include matching physical Ethernet interface types and speeds on both cluster nodes. In practical terms, you cannot build one reth bundle by mixing Fast Ethernet with Gigabit Ethernet, or by mixing different speed members inside the same redundant Ethernet interface. Juniper’s chassis cluster documentation explicitly states that mixed Ethernet interface types or speeds within a single reth interface are not supported.

Option B is correct because all member interfaces must use the same media/interface type, such as Fast Ethernet with Fast Ethernet or Gigabit Ethernet with Gigabit Ethernet. Option C is correct because the child interfaces must also operate at the same speed. Option A is wrong because speed mismatch is unsupported and can prevent a child link from joining the reth bundle. Option D is wrong because different media types are not valid within the same reth interface. Reference topics: HA Clustering, redundant Ethernet interfaces, reth child interfaces, interface type and speed requirements.