You see this behavior because your traceroute program does not
understand the ICMP "administratively prohibited" (ICMP type 3, code
13 - defined in RFC 1812) messages being sent back to it from
cpe1.reston.mci.net.
Cisco routers typically return ICMP messages of this nature to the
source of traffic which is being blocked by a traffic-filtering
ACL on the Cisco router.
- roy -