If your T1 is configured for B8ZF and ESF ask the Telco to peroform an all zeros and all ones test for over 1 minute each (over a minute is key). This failes if there is miss configured equipment on the circuit. If they still insist that the lin...

Just a quick note: Passive ftp allows both the client and the server to create connection to each other. Firewalls don't like this and some clients/servers do not support passive ftp modes. This is what I do on the router: config t ip ftp...