Network Engineering
& Operations

Hostmaster FAQ

What are the email requirments to submit a request?
What is DNS, can I use it to point to a directory?
What are the types of records used in DNS?
What are valid characters that can be used in host names?
What needs to be done if we want to change DNS records at a specific time?
How should I register my DHCP range?
What are the benefits of registering the devices on my network?
How do I register a wireless access point?
How do I configure my Active Directory DNS Server?

Last Updated 5/22/2006

What are the email requirments to submit a request?

As of 1/1/04 only plain text emails that comply with the following guidelines will be processed.

All requests need to be sent to the University hostmaster@osu.edu. Any request not from the Department Network Administrator (DNA) or secondary DNA for the network will not be processed. The email must only include the information for the IP's that need their DNS information changed. Any requests sent, as part of an email in HTML format will not be accepted. No information provided in a Microsoft Office attachment will be accepted. Fully qualified host names must be provided, including the domain using the following format:

Hostname IP or type of record if requesting a CNAME or MX
machine1.domain.ohio-state.edu IN A 128.146.xxx.xxx
alias.domain.ohio-state.edu IN CNAME server.domain.ohio-state.edu
system.domain.ohio-state.edu IN MX 10 emailserver.domain.ohio-state.edu

Requests that meet the above requirements will be completed within two to three business days.

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What is DNS, can I use it to point to a directory?

Domain Name Service (DNS) is the system that provides mapping from the Internet Protocol (IP) address to domain names. Without DNS and the Internet standard software Berkeley Internet Name Domain (BIND), running DNS every time that someone wanted to go to a website for example http://www.osu.edu/ they would have to enter http://128.146.214.28. DNS can only point to an IP address, directing a user to the correct content or directory for a service has to be configured on the server.

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What are the types of records used in DNS?

There are a few types of records that are commonly used in DNS. The following are the most commonly used records used on campus:

A Address records point a host name to an IP address.
MX Mail records direct email sent to a server or department to the correct location.
CNAME Canonical name records are used to create an alias for a machine so that multiple names can be used for one server.
PTR Reverse pointer records allow lookups by IP to find a host name.
SRV Service records are used in the windows 2000 active directory.

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What are valid characters that can be used in host names?

Due to some requirements in the way that DNS works some characters are not valid in host names. Valid names in DNS can contain both letters and numbers, but since an older version of BIND along with some resolvers have problems with the first character of a name being a number, we do not recommend names that begin with a number character.

Besides letters and numbers the only other character that can be used is the hyphen (-). The other special non-alpha numeric characters cannot be used, which include the space, underscore, forward slash and back slash.

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What needs to be done if we want to change DNS records at a specific time?

For server moves that are time sensitive, to minimize the effect on the users, notify us of your request three to five days in advance. This is to insure that both the time will fit into the schedule of the Hostmaster and to allow adjustments to the zone file to reduce the effect on users off campus.

By default the Time To Live (TTL) on departmental ohio-state.edu zone files have a TTL of 24 hours. The length of the TTL effects how frequent name servers off campus will store our records in their cache. As a result any new updates may take up to 24 hours to propagate to off campus networks, unless we reduce the TTL in preparation for your request.

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How should I register my DHCP range?

A common question I receive is how should I register in DNS my dhcp range. Since, a machine can move within the range of addresses creating individual names does not work well. We have addopted the format many ISPs use, name the range using the IP in the name. For an example if address 123.456.789.abc belonged to a networking dhcp range we would use dhcp-123-456-789-abc.net.ohio-state.edu for the name. Some departments, also like to include a building code for faster reference when trouble shooting dhcp ranges spread over several locations. If you are interested in using this name format, you only need to provide the begining and ending IPs of your dhcp range.

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What are the benefits of registering the devices on my network?

Besides complying with the Sonnet Network Policy (.pdf) it also is useful in a few other ways:

By naming the devices you are aware of being on your network, it helps in when performing a network audit. I frequently contact DNAs with lists of devices discovered without hostnames, in the event something has been added to your network without approval, tracking down the device will be easier.

Another reason to register devices is that some protocols are beginning to ask for the forward and reverse lookups, before allowing data to be transmitted. If users complain about not being able to access secure sites, (ftp/www) it may be due to a secure server performing checks to see if the host it is being queried by is a correctly registered host. This is a feature to prevent "spoofing" more servers and applications are beginning to look to see what is registered to the IP before allowing a transfer.

Also in the event that a security incident would happen concerning your department network, when the security group contacts you they will have a name besides an address which may speed up the locating of the box in question.

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How do I register a wireless access point?

To manage wireless OIT has created a Wireless Policy, included in this policy is a required name format. All campus wireless access points which must be installed with the following naming conventions to identify themselves both on the wireless network (SSID), and on the campus wired network. The naming convention assigns names based on three identifiers:

[Building ID]-ap-[Group ID]-[Unique ID].[Domain]

Building ID

This is the campus building ID (2 - 3 letters), as shown on the official campus map. The campus building numeric ID can be used instead of the letter designation, prefixed with the letter N.

Examples: BE or N280 = Baker Systems Engineering, HI = Hitchcock Hall

This is a constant identifier for AP's, and provides a standardized character string to help identify Access Points.

Group ID

This is a string of up to 10 characters which should identify the group and/or department responsible for the AP. The string should include some type of abbreviation of both the group and department, if the AP is installed by a group and not by the department's IT group.

Example: OITNSEC = OIT Network Security Group

Unique ID

This should be a unique identifier for the AP, limited to up to 5 characters. The room number where the access point is located can be used, although this does divulge the exact location of the AP. Therefore, the room number should only be used as the unique ID if the AP is in a fully secured room. Alternatively, the administrator's room number can be used instead.

Example: 449 (secure room #), F2NE1 (floor 2, northeast 1)

Domain

Example: net.ohio-state,edu, Domain used by Enterprise Networking

Example: A station BE-AP-OITNSEC-449, should be registered as

be-ap-oitnsec-449.net.ohio-state.edu on the OIT 8help wireless registration form, during the registration process the AP will be registered in the OSU Domain Name Service (DNS).

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How do I configure my Active Directory DNS Server?

To aid in the process of deploying a Windows Active Directory domain on campus we have created a guide on how we recomend to configure your servers. Anyone that is using a Microsoft DNS server should be aware that by default Windows servers do not have protection against DNS cache pollution. Microsoft has a support page that explains how to solve this issue it can be found at http://support.microsoft.com/default.aspx?scid=kb;en-us;241352.

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The Ohio State University

www.osu.edu

Hostmaster FAQ