When bundling multiple physical interfaces into a Link Aggregation Group (LAG), also known as an aggregated Ethernet bundle, all member interfaces must have identical characteristics to ensure proper operation. The most fundamental of these are link speed and duplex settings. If one member link operates at 1 Gbps and another at 10 Gbps, or if one is full-duplex and another is half-duplex, the bundle cannot be formed and will not function correctly.

A. While mismatched MTUs can cause problems, the primary and strict requirements for forming the bundle are speed and duplex.

C. A key feature of a Virtual Chassis is creating a LAG with member links on different physical chassis for redundancy.

D. Spreading member interfaces across different Packet Forwarding Engines (PFEs) is a common practice for load balancing and is not a restriction.

1. Juniper Networks. (n.d.). Understanding Aggregated Ethernet Interfaces and Link Aggregation. Junos OS Documentation. "To create a LAG

you must specify the link speed of the member links... All interfaces in the bundle must be of the same speed and in full-duplex mode." (See section: Aggregated Ethernet Interfaces Overview).

2. Juniper Networks. (n.d.). Configuring Aggregated Ethernet Interfaces. Junos OS Documentation. "All the interfaces that are part of an aggregated Ethernet bundle must have the same speed (for example

all 1-Gbps or all 10-Gbps) and be in full-duplex mode."