Inside Tufts University Information Technology

Network Engineering

Network FAQ

DHCP lease time
The default lease time for a normal DHCP client is 8 hours. Clients are supposed to check with the server halfway through a lease to make sure its still valid, which it won't be if the MAC's class has been changed. Thus, if a host's MAC has been restricted and the host is a well-behaved DHCP client, there is a theoretical maiximum of 4 hours before it effectively goes off the air.
DNS requests for static IPs
Requesting via cardinal is the correct method; it gets all the info in the correct format, archives it appropriately, and can then be processed automatically. Note that you can't request particular IPs; the assignment utility picks the next available one.
DNS updates
Requests made before 5pm are processed the same day they're received, barring extenuating circumstances in the NOC. Changes go "live" between 9pm and 10pm every night except Saturday.
Firewall ports to open for network and mail hosts
Remember to open access to the Tufts DNS, DHCP, LDAP, mail servers and scanners.
ICF configuration for Network Monitoring
The bare bones ICF changes for the Tufts Data Network include: Under ICMP tab, allow incoming echo request, allow outgoing source quench, allow redirect.
Multicast
Multicast streaming is supported in Medford, Grafton and most areas in Boston. Please contact NOC for specifics if you need it for Ghost or any other applications.
TTL (Time to Live) and DNS name changes
The default Time-to-Live on Tufts' nameservers is 24 hours. If you will be changing the name of a host, its a good idea to submit a request via Cardinal to lower the TTL to 5 minutes several days before the change.