Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
A user guide for CHEETAH hosts There are several Linux end hosts deployed at the CHEETAH network PoPs available for use by researchers. Users are invited to obtain logins on these machines to test. We provide information below in the form of a set of FAQs. 1. What can I do with a cheetah login? A cheetah login allows users to log on to any of the cheetah hosts. Any two hosts can be interconnected with a dedicated end-to-end GbEthernet circuit. It is useful to test applications, middleware or transport protocol software that requires such a high-speed dedicated circuit. Depending on your choice of hosts, you can create local-area or wide-area 1Gb/s dedicated circuits. You have to be logged into one of the end hosts connected by the dedicated circuit. On how to set up a circuit, see question below. 2. Where are these hosts located? How do I access them? Hosts are currently located at the University of Virginia (UVa), North Carolina State University (NCSU), Oak Ridge National Laboratories (ORNL, also a CHEETAH PoP), City University of New York (CUNY), MCNC (a CHEETAH PoP), and Atlanta (a CHEETAH PoP). These hosts have a primary 100Mbps Ethernet card that is connected to the Internet. Use any SSH client software, such as SecureCRT, to login to these hosts via this primary Ethernet card. Here is a list of hosts with the IP addresses of their primary NICs. In some cases, the hosts have been assigned domain names. If a domain name is not available, use its primary NIC IP address for the SecureCRT login. Location CHEETAH Internet IP address host name (primary NIC) UVa, Charlottesville, VA mvstu6 128.143.67.213 NCSU, Raleigh, NC wukong 128.109.45.180 wuneng 128.109.34.22 zelda4 198.124.42.17 zelda5 198.124.42.18 zelda1 130.207.252.131 zelda2 130.207.252.132 zelda3 130.207.252.133 ORNL, Oak Ridge, TN SOX/SLR, Atlanta, GA CUNY, New York, NY 3. Can I use telnet or some other login mechanism to log in to the CHEETAH hosts? No, the only remote login mechanism supported is SSH. Please use SSH client software, such as SecureCRT, to log in. 4. Once I log in to any one of these machines, how do I create a dedicated 1Gb/s Ethernet circuit to another one of these CHEETAH hosts? First, check if there is an existing circuit by circuit-requestor status It should return a “CHEETAH link available” message if there is no previously established circuit. Next, to set up a circuit, issue the command circuit-requestor setup destination-host bandwidth (Mbps) [holding-time (minutes)] where y destination-host should be cheetah-host-name.cheetah-demo.com or the primary NIC IP address of a cheetah host. See the table in the answer to question 2 for a list of cheetahhost-names. Note that circuit setup has to be initiated from one of the hosts on the circuit. Third-party setup is not allowed, in other words, you cannot login to zelda1 and set up a circuit from zelda2 to wuneng, for example. y Bandwidth is the desired circuit bandwidth in Mbps. y Optional holding-time is the desired circuit holding time in minutes. Default holdingtime and Max holding time are 10 minutes and 1 hour respectively. Default holdingtime will be used if a user does not explicitly provide the holding time. A user cannot ask a holding time longer than Max holding time. When the holding time expires, the circuit will be automatically released by circuit-requestor. Upon a successful circuit setup, circuit-requestor will return a Session-id to the user to uniquely identify the circuit. Session-id will be used later to release or renew the circuit. Finally, to release the circuit, issue the command circuit-requestor release session-id where session-id must match the session-id returned by setup procedure. 5. What should I do if the circuit will expire, while my applications are still running over the cheetah circuit? Circuit-requestor will send the user who created the circuit a warning message one minute earlier before the circuit expires. User can choose to either stop their applications or renew the circuit with a new holding time. To renew an existing circuit, issue the command circuit-requestor renew session-id [new-holding-time (minutes)] If no new-holding-time is provided, Default holding-time will be used to renew the circuit. The same Max holding time limitation still applies. 6. How do I know whether circuit setup was successful? Run the command ping secondary-NIC-IP-address-of-cheetah-host To find the IP address of the secondary NIC of cheetah hosts, see the table below. CHEETAH Cheetah network IP address host name (secondary NIC) mvstu6 152.48.249.106 wukong 152.48.249.102 wuneng 152.48.249.103 zelda4 10.0.0.14 zelda5 10.0.0.15 zelda1 10.0.0.11 zelda2 10.0.0.12 zelda3 10.0.0.13 7. What are preliminary checks I should execute before requesting dedicated GbE circuits? a. Type “echo $PATH”. Ensure that /usr/local/bin and /sbin are in your path. If not, add these to .bash_profile in the PATH line. b. Next type “ps aux | grep RSVPD” to ensure that the RSVPD daemon is running. c. Next type “ps aux | grep cheetahd” to ensure that cheetahd daemon is running. d. Next type “more /etc/resolv.conf” to check that the nameserver of this host has been set to 128.143.67.213 (which is a CHEETAH host that runs our own DNS server for the domain name cheetah-demo.org; this is an unregistered name). If this is not the case, then you should use secondary NIC IP addresses to initiate circuit setup. e. If any of these preliminary checks fail, send email to [email protected]. 8. How do I check to see whether the DNS entry is correct for a CHEETAH host? When logged in to any CHEETAH host, you can type the following command with the name of another CHEETAH host to see whether the CHEETAH DNS server has a correct entry. For example to see if zelda1 is on cheetah, type “host -t TXT zelda1.cheetah-demo.com” for which you will see the response zelda1.cheetah-demo.com descriptive text "OCS-available" "10.0.0.11" "00:11:95:C7:28:82". The “OCS-available” indicates that optical connectivity service is available, i.e., that zelda1 is connected to cheetah and can be reached with a dedicated GbE circuit. 9. How do I readily find the primary IP address of another CHEETAH end host while logged into a CHEETAH end host? An example: To find zelda1’s primary NIC’s IP address type “host zelda1.cheetahdemo.com” and the response provides the IP address. Replace zelda1 with the cheetah-hostname of the required CHEETAH end host. See the table in the answer to question 2 for a list of cheetah-host-names. 10. How do I readily find the secondary IP address of another CHEETAH end host while logged into a CHEETAH end host? An example: To find zelda1’s primary NIC’s IP address type “host –t TXT zelda1.cheetahdemo.com” and the response provides the IP address. The response is zelda1.cheetahdemo.com descriptive text "OCS-available" "10.0.0.11" "00:11:95:C7:28:82". The 10.0.0.11 is the secondary IP address. Replace zelda1 with the cheetah-host-name of the required CHEETAH end host. See the table in the answer to question 2 for a list of cheetah-hostnames. 11. What exactly happens when the circuit-requestor command is issued? The circuit-requestor program communicates with the cheetahd daemon running on the end host. The cheetahd first determines whether the called end host is connected to the CHEETAH network by issuing a TXT resource record query to its DNS server. The DNS server has been set on all CHEETAH hosts to be a name server that we are running at UVa for demonstration purposes. For CHEETAH hosts, the TXT resource record returns an “OCS available” indication along with the IP address and MAC address of the secondary NIC. After the circuit is setup, these addresses are used to create entries in the IP routing table and ARP table at the calling end host. These tables are updated at the called end host by the RSVP-TE Path message carrying the IP and MAC address of the calling end host’s secondary NIC in transparent user-specific parameters. See http://cheetah.cs.virginia.edu/documents/dcn/dcndesign.pdf for further details. The cheetahd daemon at the called end host communicates with the RSVPD daemon running on the same end host. This causes an RSVP-TE Path message to be generated to the control card of the SN16000 to which this host’s CHEETAH (secondary) NIC is connected. The SN16000 card runs RSVP-TE. It parses the received Path message, determines the next-hop switch through which to route the circuit, runs a simple-sum connection admission control algorithm to check bandwidth availability on the interface leading to the next-hop switch and provisions the switch fabric. It maps the GbE port to which the calling end host is connected to a virtually concatenated 21-OC1 signal on an OC192 interface if the called end host is located at another switch, or to another GbE port if the called end host is located at the same switch. The I-NNI signaling between SN16000s within the CHEETAH network is called Broadleaf. This is required only for EthernetSONET-Ethernet circuits. If a pure SONET circuit is created at an SN16000, then GMPLS overlay model signaling can be used. The Broadleaf solution for the hybrid Ethernet-SONETEthernet circuit consists of 7 OC3 SONET circuits being set up from the egress SN16000 to the ingress SN16000 within the CHEETAH network. A similar set of actions occur at the next SN16000 if the call needs to be routed via a second switch. The RSVPD daemon running at the called end host receives the Path message, alerts the cheetahd daemon about the incoming call. The latter configures the IP routing table and ARP table at the called end host. A Resv message is then sent from the called end host back to the SN16000 and through the CHEETAH network to the calling end host. The successful setup of the circuit is then announced to the calling user. 12. What is the CHEETAH network topology? See http://cheetah.cs.virginia.edu/networks/networks.html for further details Last updated: June 26, 2006 Contact: Malathi Veeraraghavan ([email protected]), Xuan Zheng, Xiuduan Fang.