Stop conflating backdoors and lawful intercept.<p>Lawful intercept is a specific method of viewing traffic passing through a network device.<p>It would be straightforward to build something, without it being a standard feature of vendor network devices, using a different standard feature of literally any enterprise level network device: port mirroring.
<a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Port_mirroring" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Port_mirroring</a><p>Port mirroring exists for many reasons and is widely available on switches for things like IDS, troubleshooting, and performance monitoring (e.g. generating netflow on an different device than the switch).<p>To use Cisco lawful intercept, you must already hold the highest admin privileges on the device.<p>Cisco almost certainly built this feature for the US agencies. The ones it has been supplying internet routers to since the commercialisation of routers, a short time after the creation of the internet by... US agencies.