Berkeley CSUA MOTD:Entry 53739
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2017/12/15 [General] UID:1000 Activity:popular
12/15   

2010/3/3-30 [Computer/Networking] UID:53739 Activity:nil
3/3     If you read this
        http://www.net.berkeley.edu/dhcp/faq.shtml
        and find why it's funny, you're an old Soda geek.  -John
        \_ Nice. Any idea who might have written this? erikk, maybe? There
           are probably a lot of Sodans in IST. -not-that-old-Soda-geek
           \_ Jon?
        \_ Scanning it, I see reference to Phil. What others?
2017/12/15 [General] UID:1000 Activity:popular
12/15   

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Cache (8192 bytes)
www.net.berkeley.edu/dhcp/faq.shtml
What's the hardware address and how do I find it on my device? The hardware address is the Media Access Control (or MAC) address that uniquely identifies the network interface in your device. be sure you identify the address of the wired interface connected to the campus network. Each digit can be either a number from 0-9 or a letter from A-F (letters are case-insensitive). The address is sometimes separated by dashes or colons (eg, 00-80-C7-CF-83-A2, 00:80:c7:cf:83:a2). On PC's, the hardware address is sometimes called the Ethernet Adapter Address or Physical Address. If you have a modem card installed, that, too, will have an adapter address, but it isn't the one you need to register for DHCP. You need the address associated with the ethernet adapter. Faculty, staff, and registered UC Berkeley students are eligible. Summer-school only and University Extension students are not eligible. An exception is a summer school student who is also admitted to attend the University during the academic year. The campus DHCP service is available on any subnet supported by IST. The campus DHCP service is also available on subnets designated as private networks where the subnet terminates on an IST managed router. To find out if your subnet is set up for DHCP service, see your departmental network contact or send email to the campus Hostmaster. The campus DHCP service will issue a lease for an IP address from a dynamic pool to any registered device. For this reason, it does not make sense to use departmental, or other specific subdomains for the DNS records of IP addresses in dynamic pools. EDU is used as a container for IP addresses used by AirBears clients. Fixed assignment of an IP address is generally restricted to one MAC address (and therefore one device). In this case, a departmental or other specific subdomain is used wherever possible for the associated DNS. Upon request, an existing or new hostname may be used instead of a default identifier. Contact the campus Hostmaster for DNS requests and questions related to fixed assignment of IP addresses via DHCP. Is there any relation between the campus DHCP service and AirBears? AirBears uses DHCP to assign IP addresses and other network configuration information to wireless clients. Unlike the campus DHCP service used with the wired network, AirBears does not require registration of MAC addresses. The DHCP servers hand out a DHCP lease to any AirBears client requesting one (provided there are addresses available). Since wireless signals are not confined to a space that may be physically secured (they often leak outside of buildings, for example), the AirBears network uses a captive portal access control system to authenticate access to the wireless network. For the campus wired network, access control has traditionally been based on the physical security of the space containing the network connection. The DHCP registration process is not an authentication mechanism; DHCP itself was not designed with any access control or authentication features. RFC 3118) The registration mechanism allows the association of attributes (such as a dynamic hostname or fixed IP address) to individual computers and records a contact for the device should it cause network or security problems. The same DHCP servers are used with AirBears and the campus DHCP service. The servers are configured to handle DHCP requests differently depending on which type of network (wireless vs. Each device you register must be used for official campus business or your own personal use. You may register devices for which you coordinate or provide IT support, as part of your University employment, but are not the primary user. Please be aware that you will be the point of contact regarding security or other problems related to each device you register. If you register devices other than your own please keep an inventory of these devices so that you may quickly respond to questions regarding them. I just registered, but I didn't get any confirmation about when I could start using DHCP? Why does the registration page say that my hardware address is already registered? The ethernet hardware address is a unique identification number built into each network interface. Chances are that the address you are attempting to register is already registered. Contact the campus Hostmaster to update the registration information for the address. " is not an ethernet address, but is a pseudo-address for the modem card. In all likelihood, when you were in the 'winipcfg' configuration, you had "PPP Adapter" highlighted in the window. You need to click on the pull-down tab and make sure the ethernet card is shown in the window. My department has a DHCP server and I've already registered my device with them, do I need to re-register to use the campus DHCP service? Yes, you will have to register separately to use the campus DHCP service. does that mean I have to reconfigure my device whenever I move between my office connection and a connection on a different subnet using DHCP? Speak with your departmental network contact (or the campus Hostmaster directly) to convert the static IP address assigned to your office connection to a fixed IP address assignment via DHCP. Is the registration of virtual addresses associated with virtual machines permitted? You may register virtual addresses associated with virtual machines provided you follow these guidelines to avoid conflicts. First, make sure that the virtual hardware (or MAC) address you intend to use will not conflict with any address that may be assigned to hardware by a manufacturer. Since addresses assigned to hardware may not be modifiable, virtual machines must avoid potential conflicts with hardware when selecting an address. Determine if your virtual environment assigns addresses from a pool with one or more assigned OUIs. For example, the OUI of the address 00:de:ad:be:ef:00 is 00-de-ad. com/xenwiki/XenNetworking#head-d5446face7e308 f577e5aee1c72cf9d156903722 If your virtual environment does not have a pool of addresses for assignment to virtual machines, you will need to create your own pool. To do this, choose an address from one of the hardware addresses associated with the server that hosts your virtual environment. Convert the first byte of the address to binary, set the second most least significant bit to one, and convert the resulting binary value back to hex. This operation converts the hardware address into a locally administered address. If you need additional addresses, increment this initial address as needed to obtain more addresses. For example, if 00:de:ad:be:ef:00 is a hardware address, the locally assigned address is 02:de:ad:be:ef:00. Once you've determined the MAC address you will use with your virtual machine, register the address with the campus DHCP service. If you registration succeeds (the address is not already in use by someone else) you may use the address. Take whatever steps are required in your virtual environment to ensure that the MAC address does not change in the future. If your registration did not succeed because the address was already registered, based on the information gathered previously generate a new address and attempt to register it. Dynamic updates to the DNS are only available via the campus DHCP service. Dynamic updates to the DNS are only available via the campus DHCP service. Are CNAME and MX records referring to Dynamic DNS hostnames allowed? Such records create inconsistencies in the DNS when the hostnames they refer to are not present in the DNS. How do I determine the static assignment of an IP address associated with a network connection? The campus Hostmaster maintains records of static assignment of IP addresses to network connections identified by cable id. Before asking Hostmaster for the IP address and related information for a particular network connection, determine the cable id of the connection (usually found on the wall box or outlet). EDU requesting the IP address and related information for the cable id. EDU> Subject: Static IP address assignment for cable id S2484-113-S204-002-D Greetings Hostmaster, Please respond with the IP address ...