Why is a no-proxy configuration recommended in tunnel mode?

A no-proxy configuration in tunnel mode is recommended primarily to prevent routing issues through local networks. By avoiding the use of proxy configurations, the traffic can be routed more straightforwardly and directly, which helps in maintaining optimal performance and ensuring that appropriate routing paths are followed. This configuration minimizes complications that may arise from specific local routing policies or existent network topologies.

When a proxy is introduced, it can create additional layers in the routing process, leading to potential misdirection of traffic or increased latency. This is particularly important in environments where multiple local gateways or subnets exist, as each network might have unique routing requirements. A no-proxy setup in these circumstances ensures that traffic flows smoothly without getting affected by conflicting local policies.

The other options, while relevant to tunnel mode configurations in their own contexts, do not specifically address the primary concern of routing integrity that a no-proxy setup is designed to alleviate. Thus, the emphasis on preventing routing issues makes this the most compelling reason for recommending a no-proxy approach in tunnel mode.