Node - Help
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Node - Help |
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| Summary |
SummaryThe Node record type is the most common record accessed by LNAs. Node records include essential information about networked devices like name and hardware address. This is also where LNAs assign IP addresses. NetDB comes with the following Node types: Regular, Template, IPC, Router, Advanced and Virtual. New types can be added to accommodate changes in networking technology. Most LNAs will only need access to the Regular, Template and Virtual Node types. A Node can be more than one type. Regular - This is the most common type of Node. Regular Nodes are used for most computers, printers and networking equipment. Regular Nodes have one DNS name assigned. Template - This Node type does not have an
IP address but an address space instead. LNAs can use templates to have one or
more standard NetDB entries for their networks, say one for each subnet or
building. All NetDB users with Node record access can also create Nodes of type
Template.
IPC (IP Connectivity Provider) - This Node type reserves
a range of addresses to be handed out and is typically used for terminal servers.
Most LNAs do not have access to this Node type.
Router - This Node type has the same fields as a Regular Node.
However, router Node types have separate access restrictions. Usually, only staff who
maintain routers
, on campus or in the Medical Center,
have access to router records.
Advanced - This Node type allows nodes to have multiple
names, names for their interfaces, and names for their interface IP addresses.
This is useful for computers with multiple network adapters and those that host
multiple websites. Each Node name (but not Interface or IP address names) may
have it's own aliases and MXes. Generally, Advanced Node type access is granted
by special request.
Virtual - This Node type represents a node that has no
physical presence. All NetDB users with Node record access can use this Node
type. It is purely informational and can be useful for creating reports from
full search.
Changing Node Type
To change the Node type, simply click on the buttons at
the top of the Create Node or Modify Node page. The checkmark on the button
means that Node type is selected. A Node can be an Advanced IPC Router.
But Template Nodes cannot also be Advanced, IPC or Router types. Verify Button
Due to the nature of web pages, IP addresses cannot be confirmed
as soon as they are entered. The "Verify " button tells NetDB to check
for the following:
Required fields are marked with a red asterisk on the Create Node or
Modify Node pages.
DNS records are specified in the name section. Below is the list of how
NetDB terms map to the equivalent DNS record.
These three (3) fields must obey the following
Internet naming standards:
For Node name, alias and mail alias, if no Domain name is specified, your
default Domain (set in User Profile) is used. For most Users, the default Domain is
stanford.edu.
Note that there are two special domains- .SUNet
and .NoDomain. Names in the .SUNet domain are only resolved for
Stanford hosts. This is useful for hosts on private address spaces (not
reachable from the Internet). Names in the .NoDomain domain are never resolved by DNS
servers. They are typically used as placeholders.
Name - Name is simply the name of the Node. An Advanced Node can
have multiple names. If no Domain name is specified, your default Domain (set in User Profile)
is used. For most Users, the default Domain is stanford.edu
Alias - Alias is the alias for the Node and is equivalent to
CNAME record in DNS.
MX - MX or Mail Alias allows email to be redirected.
If "box1" is entered as a mail alias for Node "box2", that means that mail
sent to anyone@box1 will actually be redirected to box2. A name can only be added as an MX if
the node corresponding to that name is in the same group as the user. For instance, if a user
tries to enter node2 as an MX for node1 (i.e., node1 will receive mail for node2), the user must
have group rights to node2.
For example, suppose Node A has a mail alias B. When SMTP (simple mail transport
protocol) server C is asked to send mail to somebody@B.stanford.edu. Server C will
ask the Stanford DNS servers for the MX for B.stanford.edu. The DNS servers
will return the IP address for A.stanford.edu. Server C then will send the mail to
A.stanford.edu. In another example, if server C is asked to send mail to
somebody@A.stanford.edu, server C will query the DNS servers for the MX for
A.stanford.edu. In this case, there is no MX record for A.stanford.edu.
Then server C will query the DNS servers for an A record for A.stanford.edu. The DNS
servers will return the IP address for A.stanford.edu.
Below is the record for A.stanford.edu:
Node Type - Select the desired Node types by clicking on the buttons.
Selected Node types will have checkmarks on the button. The page will also be refreshed to
add the fields associated with additional Node types. Note that a template Node cannot be
combined with other Node types.
State - A measure of a node's network behavior.
Most nodes should be in the Good state. Nodes that are misbehaving or compromised
in some way can be put into the Dubious, Tainted, or Vile states
depending on the nature and/or degree of the malady. These bad states may limit a node's
network access various ways. The following table shows how the network treats nodes in the
various states:
The Unknown state should be used when the true state of a node is unknown.
Because nodes in the Unknown state could compromised, they are treated as
unknown to the DHCP service, just like nodes the Dubious state.
To switch a node into or out of the Exempt state requires a special privilege,
generally granted to LNAs of critical nodes. Those LNAs use the Exempt state for
nodes that should never suffer the consequences of being moved into the bad states.
Node entries are marked Stale if they and the nodes they represent meet the conditions
outlined in the
Stale and Useless Nodes SUNet report. Node entries in the Exempt state are immune from
being marked Stale. Nodes that remain stale for 90 days are deleted. Department - department the computer belongs to. Select the desired
department from list. To add a new department or to change the list of departments, submit
a ticket to HelpSU.
Location - the building where the computer is located. Select the
desired location from the list. To add a new building or to change the list of buildings,
submit a ticket to HelpSU.
Room - the room where the computer is located
Make and Model - the type of computer it is. Select the Make and
Model from the lists. To add a new model, click on the New button. To add a new Make,
submit a ticket to HelpSU.
Operating System - Select an operating system from the dropdown
list. If the computer has multiple operating systems, click on Add Another. To create
a new operating system, click on New.
Administrators - Administrators are individual people or Admin
Teams that are responsible for a computer. Being listed as an Administrator or Admin
Team does not give rights to modify a NetDB record. This field indicates the custodian
for the physical or virtual device associated with the record.
List individuals by using their full names or their SUNet IDs.
You can click on Verify to have NetDB check and resolve the names before you try to save the record.
If you choose to verify, entries will be checked against the online Stanford directory;
if they are not found in the directory or if a name matches multiple people in the directory, an
error will occur. If an exact match is found, the person will be returned with a checked box. If
multiple matches are found, a list of people and associated departments will be returned unchecked.
Check to select the right administrator. The verification process is thus especially useful if you use
SUNet IDs since it will show you information about the people connected to the
SUNet IDs so you'll know if you entered the right SUNet IDs. Note that the
directory lookup looks for matches on SUNet IDs, last name and email address.
Note that verification is also done when the Node record is saved.
An Admin Team is a set of people who are responsible
for the computer. For example, the Computer Resource Center (CRC) may contract
with a department to support their computers. Instead of listing all the
people in CRC as administrators, it's simpler to list the CRC Admin Team
as an administrator. Admin Teams must be followed by a semicolon when entered
as a node administrator (e.g., "CRC;").
If the administrator is not associated with Stanford and
does not have a SUNet ID, list Admin Team "OUTSIDE;"
as the administrator and add contact information in the Comment field.
Users - This optional field lists the user of this computer.
List individuals by using their full name or their SUNet IDs. You can click on
Verify to have NetDB check and resolve the names before you try to save the record.
If you choose to verify, entries will be checked against the online Stanford directory;
if they are not found in the directory or if a name matches multiple people in the directory, an
error will occur. If an exact match is found, the person will be returned with a checked box. If
multiple matches are found, a list of people and associated departments will be returned unchecked.
Check to select the right user. The verification process is thus especially useful if you
use SUNet IDs since it will show you information about the people connected to the
SUNet IDs so you'll know if you entered the right SUNet IDs. Note that the
directory lookup looks for matches on SUNet IDs, last name and email address.
Note that verification is also done when the Node record is saved.
Custom Fields - These four (4) custom
fields allow NetDB Users to create their own fields for searching and
reporting. Some examples: Asset Tag #, Lab Name, or Department Division.
Each field has a label and a value; for example "Label: Lab Name"
and "Value: Smithfield Lab" would make one custom field.
Custom Field Views - Custom field views present complex
custom field data in a user-friendly fashion.
When a custom field view is selected the custom fields related to that view
are rendered in HTML. If those custom fields didn't exist when the view was
selected they are created at that time. With a view selected, switching to a
different view or no view at all stores the data corresponding to the current
view selections in the appropriate custom fields. The Blast It
button removes the custom fields (labels and data) associated with the
currently selected view.
Custom views provide their own documentation. After a view is selected,
check for a link - either in the gray Custom Fields bar or in the
custom view itself - to get more information about that particular custom
view.
The association between IP addresses, hardware addresses,
DHCP/BootP and Roaming DHCP is quite flexible in NetDB. Each interface
can have the following: Add Another Interface
Interfaces roughly correspond to network cards. If a Node
has multiple network cards (for example, docking station at office, PCMCIA
card at home), assigning multiple interfaces allows the Node to get different
IP addresses based on what hardware address is seen. To add another interface,
click on the "Add Another Interface" button
in the Interface Information bar (about halfway down the Create Node or
Modify Node page).
Hardware address - This 12-character hexadecimal number
can be entered in the common hardware address formats below but will always be
shown in the dotted format (1234.5678.9abc). Hardware addresses must be unique
throughout NetDB. Hardware addresses are also required in order to enable
DHCP/BootP and Roamng DHCP.
Interface Name (Advanced Node type only - Interface names would
probably be used for computers that host multiple websites or services.
DHCP/BootP - Checking the DHCP/BootP
box tells the DHCP servers to respond to DHCP requests from the associated
hardware address. This flag cannot be set without a hardware address.
This flag is also required to enable Roaming DHCP. For more information
about DHCP, see DHCP Help.
Roaming - Checking the Roaming box enables Roaming DHCP.
Roaming DHCP is usually used for laptops that move from location to location.
To set Roaming, a valid hardware address and the DHCP/BootP flag are also required.
For more information, see DHCP Help.
IP Address - IP addresses can be assigned in a number of
ways. The address box overrides the address space dropdown list.
Otherwise, NetDB will look for the next available address
in the address space, starting from the specified address.
Valid IP Address format is in dotted octet form: 171.64.60.10.
Valid Address space formats are shown below:
For more information, see Address Spaces .
Because of the nature of web pages, IP addresses cannot
be confirmed as soon as they are entered. The "Verify address"
button tells NetDB to see check if the addresses are already used. Note
that verification is also done when the Node record is saved
IP Address Name (Advanced Node type only) -
IP address names would probably be used for computers that
host multiple websites or services. To check if the names are already
used, click on the "Verify address & name" button.
PTR Pref (Advanced Node type only) - This controls what
the DNS returns for reverse lookups of the IP address. If set to All,
then all existing IP address, Interface, and Node names will be returned in no
particular order. If set to Closest, then the first existing IP
address name, Interface name, or Node name will be returned. Closest
is the default and generally recommended since many applications are confused
by multiple answers to a reverse lookup.
For example, given this Node entry:
reverse DNS lookups for the two IP addresses yield:
% host 171.64.60.11 DHCP Options - Because DHCP Options are rare in Nodes, this
window is normally hidden. Click the Display button to reveal it. If a Node
has DHCP options, this window will already be open. Enter DHCP options one per line,
using the syntax <dhcp option> = <value>. For more information about
DHCP options, see the DHCP Help.
IPC Section (IPC Node type only)
IPC addresses are addresses that this Node will pass out.
The easiest way to assign a block of IPC addresses is to select an address space
(usually the same as the address space of the IPC) and put the number of desired
addresses in the Count box. NetDB will try to find a contiguous block of IP
addresses to assign. To see these addresses before saving the Node record, click
on "Verify address & name" in the IPC section. Note that IPC addresses
are automatically assigned names. Verification is also done when a Node record is saved.
IPC Address - List of addresses that an IPC Node will pass out. IPC Address Name - Automatically assigned to an IPC address,
this name is generated as DN<IPC address in hex>
For example, for IPC address 171.64.3.5, the
automatic name would be "dnab400305"
(hex AB = 171, hex 64 = 40, etc.) This name can be changed, but
that is not generally recommended.
Count - Count is the number of requested IPC addresses.
If Count is not specified, Count is assumed to be 1.
Expiration Date - This is an informational field provided for the
convenience of LNAs. Setting node expiration dates allows LNAs to use
full search to find expired nodes to delete or update. This
can be quite powerful in combination with the full search CSV
export format and the NetDB command-line interface. NetDB
does not take any action based on the expiration date; it is purely an informational field
for LNAs to use as they see fit.
Group - Only NetDB Users in the same Group as this record or with All
Group access can modify or delete this Node. User must also have record access to Nodes and
the appropriate Node types. A Node can be in multiple Groups.
Comment - This searchable field is for any additional information.
Only printable characters are valid for comments. The printable character set consists of
the alphabet, any numbers, all punctuation and spaces. For example, the carriage return
is a non-printable character.
Created By - This field gives the full name and SUNet ID
of the NetDB User who created this Node and the date it was created.
Last Modified By - This field gives the full name and SUNet ID
of the NetDB User who last modified this Node and the date it was last modified.
Special Configurations (Wireless, Multiple
Locations, Etc.)
1. Computer with multiple network cards - Create a node record with one interface
per network card. Assign IP addresses and hardware addresses appropriately.
Example 2. Computer used in two on-campus locations with one network card - Assign 2 IP
addresses to one interface with DHCP. DHCP will hand out IP address based on location.
Example 3. Computer used in office and roaming - Assign one IP addresses to
an interface with roaming DHCP. DHCP will give the fixed IP if the machine is on
the office net and will give a roaming DHCP address otherwise.
Example 4. Laptop only roams on campus (no fixed address) - Create a record with
the hardware address, DHCP, roaming and no IP address.
Example 5. Laptop used between dorms/Stanford West and campus - The student
should register the machine in the dorms. The LNA then requests access to that record
through HelpSU or Residential Computing (appropriate group access will be
added to that record). The LNA assigns a campus IP address.
Example |
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