DnDns - A .NET DNS Client Resolver Library

NEW POST: Compact Framework

jmonty — Mon, 28 Apr 2008 17:07:13 GMT

LiquidCaffeine wrote:
Does this work with CF 2.0 and up, or is there something similiar? In particuliar, I need to do a MX record lookup on an email address to verify valid addresses from a Windows Mobile 5 platform.

I suspect it would...there's nothing too fancy in the code. If you are able to give it a shot, let me know if it works or not. If I can get around to it, I'd be interested to try this out as well...

NEW POST: Compact Framework

LiquidCaffeine — Thu, 24 Apr 2008 13:40:25 GMT

Does this work with CF 2.0 and up, or is there something similiar? In particuliar, I need to do a MX record lookup on an email address to verify valid addresses from a Windows Mobile 5 platform.

NEW POST: UDP Timeout concerns

jmonty — Sun, 06 Apr 2008 01:27:29 GMT

This discussion has been copied to a work item. Click here to go to the work item and continue the discussion.

CREATED ISSUE: UDP Timeout concerns

jmonty — Sun, 06 Apr 2008 01:27:27 GMT

I appreciate the work you put into this. We were just talking about implementing something like this in-house. You saved us some time! I had one issue come up while using it though. I had a situation where a DNS server didn't exist or wasn't properly set, so the UDP Receive function would hang indefinitely. I changed your code to take in a timeout_ms parameter in the Resolve function, and I set the underlying socket receive timeout to use it so everything could dispose properly when it timed out. Works like a charm now! Thanks!

Here's a snippet

UdpClient udpClient = new UdpClient();
try
{
udpClient.Connect(ipep);
udpClient.Send(bDnsQuery, bDnsQuery.Length);

udpClient.Client.ReceiveTimeout = timeout_ms; //added socket timeout here.
recvBytes = udpClient.Receive(ref ipep);

}
finally
{
udpClient.Close();
}

NEW POST: UDP Timeout concerns

jmonty — Sat, 05 Apr 2008 19:27:43 GMT

Really! I expected there would be a default timeout of some sort (not infinite!)....thanks for the info on adjusting it on the underlying socket! I'll adjust the code here accordingly.

NEW POST: UDP Timeout concerns

nlb6665 — Mon, 17 Mar 2008 21:14:36 GMT

UPDATED WIKI: Home

jmonty — Thu, 13 Mar 2008 20:43:03 GMT

Project Description
A DNS protocol library written completely in managed code. Supports common DNS records types like A, CNAME, MX, SRV, and more.

Background Information (my blog)
http://choosing-a-blog-url-sucks.blogspot.com/2008/02/dndns-net-dns-client-library-resolver.html.

Quick HOWTO Reference (Code Samples)

How to do a basic name lookup - A Record Lookup
How to do a reverse name lookup - PTR Record Lookup
How to lookup SPF Records - TXT Record Lookup
How to discover Mail server for a particular Domain - MX Record Lookup

For an extensive RFC reference for DNS: http://www.dns.net/dnsrd/rfc/

DnDns Supported Record Types

AAAA
AFSDB
A
ATMA
CNAME
HINFO
ISDN
LOC
MB
MG
MINFO
MR
MX
NS
PTR
RP
RT
SOA
SRV
TXT
WKS
X25

dndns_pad_file.xml

UPDATED WIKI: Home

jmonty — Thu, 13 Mar 2008 20:31:50 GMT

How to do a basic name lookup - A Record Lookup
How to do a reverse name lookup - PTR Record Lookup
How to lookup SPF Records - TXT Record Lookup
How to discover Mail server for a particular Domain - MX Record Lookup

DnDns Supported Record Types

AAAA
AFSDB
A
ATMA
CNAME
HINFO
ISDN
LOC
MB
MG
MINFO
MR
MX
NS
PTR
RP
RT
SOA
SRV
TXT
WKS
X25

For an extensive RFC reference for DNS: check here: http://www.dns.net/dnsrd/rfc/

dndns_pad_file.xml

CREATED FEATURE: Add Support for Dynamic Updates (DNS UPDATE)

jmonty — Thu, 13 Mar 2008 20:30:09 GMT

DNS servers allow clients to dynamically update their DNS records when their IP address changes (for instance, useful when a client receives a new IP Addresses from a DHCP server).

References:
RFC 2136: Dynamic Updates in the Domain Name System (DNS UPDATE)
http://www.ietf.org/rfc/rfc2136.txt

RFC 2137: Secure Dynamic Updates in the Domain Name System (DNS UPDATE)

RFC 3007: Secure Domain Name System (DNS) Dynamic Update
http://www.ietf.org/rfc/rfc3007.txt

UPDATED RELEASE: DnDns Library Release 2

Tue, 11 Mar 2008 14:54:11 GMT

Release will bring in additional features.

CREATED FEATURE: Add Support for Zone Transfers (AXFR)

jmonty — Tue, 11 Mar 2008 13:58:34 GMT

NOTE: "Because accuracy is essential, TCP or some other reliable protocol must be used for AXFR requests.", RFC 1024

References:
RFC 1034 - DOMAIN NAMES - CONCEPTS AND FACILITIES
http://www.ietf.org/rfc/rfc1034.txt

RFC 1996 - A Mechanism for Prompt Notification of Zone Changes (DNS NOTIFY)
http://www.ietf.org/rfc/rfc1996.txt

Notes on Implementing AXFR Zone Transfers (from DJB)
See: http://cr.yp.to/djbdns/axfr-notes.html

Also explore IXFR, RFC 1995 - Incremental Zone Transfer in DNS
http://www.ietf.org/rfc/rfc1995.txt

UPDATED WIKI: Home

jmonty — Fri, 08 Feb 2008 07:35:33 GMT

How to do a basic name lookup - A Record Lookup
How to do a reverse name lookup - PTR Record Lookup
How to lookup SPF Records - TXT Record Lookup
How to discover Mail server for a particular Domain - MX Record Lookup

DnDns Supported Record Types

AAAA
AFSDB
A
ATMA
CNAME
HINFO
ISDN
LOC
MB
MG
MINFO
MR
MX
NS
PTR
RP
RT
SOA
SRV
TXT
WKS
X25

dndns_pad_file.xml

UPDATED WIKI: Home

jmonty — Fri, 08 Feb 2008 07:23:20 GMT

How to do a basic name lookup - A Record Lookup
How to do a reverse name lookup - PTR Record Lookup
How to lookup SPF Records - TXT Record Lookup
How to discover Mail server for a particular Domain - MX Record Lookup

DnDns Supported Record Types

AAAA
AFSDB
A
ATMA
CNAME
HINFO
ISDN
LOC
MB
MG
MINFO
MR
MX
NS
PTR
RP
RT
SOA
SRV
TXT
WKS
X25

dndns_pad_file.xml

UPDATED WIKI: Home

jmonty — Fri, 08 Feb 2008 07:21:18 GMT

How to do a basic name lookup - A Record Lookup
How to do a reverse name lookup - PTR Record Lookup
How to lookup SPF Records - TXT Record Lookup
How to discover Mail server for a particular Domain - MX Record Lookup

DnDns Supported Record Types

AAAA
AFSDB
A
ATMA
CNAME
HINFO
ISDN
LOC
MB
MG
MINFO
MR
MX
NS
PTR
RP
RT
SOA
SRV
TXT
WKS
X25

UPDATED WIKI: Home

jmonty — Fri, 08 Feb 2008 07:20:39 GMT

How to do a basic name lookup - A Record Lookup
How to do a reverse name lookup - PTR Record Lookup
How to lookup SPF Records - TXT Record Lookup
How to discover Mail server for a particular Domain - MX Record Lookup

DnDns Supported Record Types

AAAA
AFSDB
A
ATMA
CNAME
HINFO
ISDN
LOC
MB
MG
MINFO
MR
MX
NS
PTR
RP
RT
SOA
SRV
TXT
WKS
X25

UPDATED WIKI: How to lookup SPF Records

jmonty — Tue, 05 Feb 2008 16:02:00 GMT

How to Lookup SPF Records for a Domain

SPF, or Sender Policy Framework, takes advantage of the DNS TXT record types to store information about the authorized mail servers for your domain.
ref: http://www.openspf.org/

SPF Records are simple TXT Record types within the DNS System.

string dnsServer = "192.168.0.1";
string domainToResolve = "atgi.com";
 
// Use NsType.TXT for SPF lookups
DnsQueryRequest request = new DnsQueryRequest();
DnsQueryResponse response = request.Resolve(dnsServer, domainToResolve, NsType.TXT, NsClass.INET, ProtocolType.Udp);
 
Console.WriteLine("Bytes received: " + response.BytesReceived);
 
// Enumerate the Answer Records
Console.WriteLine("Answers:");
foreach (IDnsRecord record in response.Answers)
{
    Console.WriteLine(record.Answer);
    Console.WriteLine("  |--- RDATA Field Length: " + record.DnsHeader.DataLength);
    Console.WriteLine("  |--- Name: " + record.DnsHeader.Name);
    Console.WriteLine("  |--- NS Class: " + record.DnsHeader.NsClass);
    Console.WriteLine("  |--- NS Type: " + record.DnsHeader.NsType);
    Console.WriteLine("  |--- TTL: " + record.DnsHeader.TimeToLive);
    Console.WriteLine();
}

Output

Bytes received: 88
Answers:
text: v=spf1 ip4:70.61.58.69 mx a:derrida.atgi.com -all
  |--- RDATA Field Length: 50
  |--- Name: atgi.com.
  |--- NS Class: INET
  |--- NS Type: TXT
  |--- TTL: 1800

UPDATED WIKI: How to lookup SPF Records

jmonty — Tue, 05 Feb 2008 16:01:44 GMT

How to Lookup SPF Records for a Domain

SPF, or Sender Policy Framework, takes advantage of the DNS TXT record types to store information about the authorized mail servers for your domain.

ref: http://www.openspf.org/

SPF Records are simple TXT Record types within the DNS System.

string dnsServer = "192.168.0.1";
string domainToResolve = "atgi.com";
 
// Use NsType.TXT for SPF lookups
DnsQueryRequest request = new DnsQueryRequest();
DnsQueryResponse response = request.Resolve(dnsServer, domainToResolve, NsType.TXT, NsClass.INET, ProtocolType.Udp);
 
Console.WriteLine("Bytes received: " + response.BytesReceived);
 
// Enumerate the Answer Records
Console.WriteLine("Answers:");
foreach (IDnsRecord record in response.Answers)
{
    Console.WriteLine(record.Answer);
    Console.WriteLine("  |--- RDATA Field Length: " + record.DnsHeader.DataLength);
    Console.WriteLine("  |--- Name: " + record.DnsHeader.Name);
    Console.WriteLine("  |--- NS Class: " + record.DnsHeader.NsClass);
    Console.WriteLine("  |--- NS Type: " + record.DnsHeader.NsType);
    Console.WriteLine("  |--- TTL: " + record.DnsHeader.TimeToLive);
    Console.WriteLine();
}

Output

Bytes received: 88
Answers:
text: v=spf1 ip4:70.61.58.69 mx a:derrida.atgi.com -all
  |--- RDATA Field Length: 50
  |--- Name: atgi.com.
  |--- NS Class: INET
  |--- NS Type: TXT
  |--- TTL: 1800

UPDATED WIKI: Home

jmonty — Tue, 05 Feb 2008 15:58:45 GMT

How to do a basic name lookup - A Record Lookup
How to do a reverse name lookup - PTR Record Lookup
How to lookup SPF Records - TXT Record Lookup
How to discover Mail server for a particular Domain - MX Record Lookup

DnDns Supported Record Types

AAAA
AFSDB
A
ATMA
CNAME
HINFO
ISDN
LOC
MB
MG
MINFO
MR
MX
NS
PTR
RP
RT
SOA
SRV
TXT
WKS
X25

UPDATED WIKI: Home

jmonty — Tue, 05 Feb 2008 15:13:13 GMT

Project Description
A DNS protocol library written completely in managed code. Supports common DNS records types like A, CNAME, MX, SRV, and more.

Quick HOWTO Reference (Code Samples)

How to do a basic name lookup - A Record Lookup
How to do a reverse name lookup - PTR Record Lookup
How to lookup SPF Records - TXT Record Lookup
How to discover Mail server for a particular Domain - MX Record Lookup

For some background info see this post on my blog:
http://choosing-a-blog-url-sucks.blogspot.com/2008/02/dndns-net-dns-client-library-resolver.html.

DnDns Supported Record Types

AAAA
AFSDB
A
ATMA
CNAME
HINFO
ISDN
LOC
MB
MG
MINFO
MR
MX
NS
PTR
RP
RT
SOA
SRV
TXT
WKS
X25

CREATED ISSUE: Add IPv6 Network Support

jmonty — Tue, 05 Feb 2008 15:11:59 GMT

Currently only IPv4 is used to query DNS Servers. As IPv6 become more prevalent, DnDns needs to support IPv6 networks as well.