An internal Federal Bureau of Investigation presentation states that counterfeit Cisco routers imported from China may cause unexpected failures in American networks. The equipment could also leave secure systems open to attack through hidden backdoors. The scope of the problem is broad and results from a complicated supply chain originating in Shen Zhen.
From a narrow project failures perspective, network problems caused by this equipment should be treated as any other hardware malfunction. Of course, the entire concept of third parties using compromised hardware to infiltrate public and private systems in the United States is another matter entirely.
Faulty networking hardware can be a nightmare to troubleshoot and fix. For example, the U.S. Customs and Border Protection (CBP) location at Los Angeles Airport (LAX) suffered a failed router last year; the problem delayed 20,000 passengers before technicians successfully isolated and repaired the issue.
The following slides, pulled from the larger presentation, indicate how seriously the FBI is taking this threat to national security.