---
title: client.socket.tcp_info
summary: null
url: >-
  https://www.fastly.com/documentation/reference/vcl/variables/client-connection/client-socket-tcp-info
---

**Type:** BOOL  
**Access:** read-only

**Available in:** recv, deliver, log, error

The value of this variable indicates whether `tcp_info` functionality is
available for accurate calculation of other variables. Examples of
dependent functionality are variables with `tcpi` in their names, as
well as `client.socket.nexthop`, and some logging. When `tcp_info`
functionality is available, one is returned, otherwise zero.