--collapsed" id=initial-zipkin-header><div class=faq-block-question><span class=faq-block-question__text>What generates the initial Zipkin (B3) HTTP headers?</span><div class=faq-block-question__icon><svg class="icon dropdown-arrow"><use xlink:href="/v1.16/img/icons.svg#dropdown-arrow"/></svg></div></div><div class=faq-block-answer><p>The Istio sidecar proxy (Envoy) generates the initial <a href=https://www.envoyproxy.io/docs/envoy/latest/configuration/http/http_conn_man/headers#x-request-id>headers</a>, if