Subject: [MIPSHOP-MIH-DT] DNS SRV records

From: Vijay Devarapalli <[email-masked]>
Date: Wed, 05 Dec 2007 10:10:49 -0800

I was chatting with Telemaco this morning and he told me that
you guys are writing a draft on reserving a new DNS SRV record.
DNS SRV records are not maintained by the IANA (no IETF
involvement). The SRV records are maintained at

http://www.dns-sd.org/ServiceTypes.html

You just need to send an email to add a new SRV record.

There is some discussion on using DNS SRV records for MIPv6
home agent lookup. See section 5.1.2 of RFC 5026.

Vijay

_______________________________________________
MIPSHOP-MIH-DT mailing list
[email-masked]
https://www1.ietf.org/mailman/listinfo/mipshop-mih-dt

---

From: <[email-masked]>
Date: Wed, 5 Dec 2007 12:33:12 -0600

We are using NAPTR records, SRV record is not enough for the discovery,
as we do not know the fqdn of the server(s).
But thanks for the pointer.

- gabor

-----Original Message-----
From: ext Vijay Devarapalli [mailto:[email-masked]] 
Sent: Wednesday, December 05, 2007 10:11 AM
To: [email-masked]
Subject: [MIPSHOP-MIH-DT] DNS SRV records

I was chatting with Telemaco this morning and he told me that you guys
are writing a draft on reserving a new DNS SRV record.
DNS SRV records are not maintained by the IANA (no IETF involvement).
The SRV records are maintained at

There is some discussion on using DNS SRV records for MIPv6 home agent
lookup. See section 5.1.2 of RFC 5026.

Vijay

---

From: Vijay Devarapalli <[email-masked]>
Date: Wed, 05 Dec 2007 11:17:16 -0800

> as we do not know the fqdn of the server(s).

I am probably missing some context then. I haven't really followed
the discussions so far. Sorry about that.

But a question on SRV records. You would be creating a label,
something like "_mih._udp.example.com". You would then set aside
a new SRV record for the above label. Then the mobile node would be
configured to do a DNS lookup based on the above label. example.com
can be translated into any realm.

Isn't this sufficient? Not clear why you need NAPTR records.

Vijay

---

From: <[email-masked]>
Date: Wed, 5 Dec 2007 14:31:56 -0600

Vijay,

NAPTR records provide a mapping from a domain to the SRV record for
contacting a server with the specific transport protocol in the NAPTR
services field.

The NAPTR record lets you to look at a specific service in a specific
domain. The response will tell you if whether that domain has a server
or not, and if yes, what kind of transport protocol and the order of
preference. Once you have that information, you can construct an SRV
record to find the server which provides the service with the desired
transport.

In the example you gave you made the assumption that the domain hosts an
mih service using udp.

- gabor

-----Original Message-----
From: ext Vijay Devarapalli [mailto:[email-masked]] 
Sent: Wednesday, December 05, 2007 11:17 AM
To: Bajko Gabor (Nokia-SIR/MtView)
Cc: [email-masked]
Subject: Re: [MIPSHOP-MIH-DT] DNS SRV records

[email-masked] wrote:
> We are using NAPTR records, SRV record is not enough for the 
> discovery, as we do not know the fqdn of the server(s).

I am probably missing some context then. I haven't really followed the
discussions so far. Sorry about that.

But a question on SRV records. You would be creating a label, something
like "_mih._udp.example.com". You would then set aside a new SRV record
for the above label. Then the mobile node would be configured to do a
DNS lookup based on the above label. example.com can be translated into
any realm.

Vijay

---

From: Vijay Devarapalli <[email-masked]>
Date: Wed, 05 Dec 2007 23:02:52 -0800

Gabor,

Sure you can use NAPTR records for the mobile node to figure out
the FQDN on which it needs to perform a DNS lookup. But it could
be as simple as the mobile node being configured with either
_mih._udp.example.com or _mih._tcp.example.com. Or perhaps
configured with both. The mobile node will do a DNS lookup on the
first FQDN and then the second one.

If there is no MIH server available in a particular network, the
mobile node won't get any response.

Note that NAPTR is not that widely implemented. So you might want
to make sure that DNS lookup for the MIH server can work without
using NAPTR.

Vijay

---

From: <[email-masked]>
Date: Thu, 6 Dec 2007 18:02:27 -0600

Taking your comment more generically, I think you are asking for a
fallback mechanism, in case a NAPTR record does not exists for that
application tag. 

I thought it is implicit from the existing standards that in case you
know the application and the transport, you do not need to make a NAPTR
query, but only an SRV. So, this may not need to be explicitely
specified, but I need to doublecheck this.

- gabor

-----Original Message-----
From: ext Vijay Devarapalli [mailto:[email-masked]] 
Sent: Wednesday, December 05, 2007 11:03 PM
To: Bajko Gabor (Nokia-SIR/MtView)
Cc: [email-masked]
Subject: Re: [MIPSHOP-MIH-DT] DNS SRV records

Gabor,

Sure you can use NAPTR records for the mobile node to figure out the
FQDN on which it needs to perform a DNS lookup. But it could be as
simple as the mobile node being configured with either
_mih._udp.example.com or _mih._tcp.example.com. Or perhaps configured
with both. The mobile node will do a DNS lookup on the first FQDN and
then the second one.

If there is no MIH server available in a particular network, the mobile
node won't get any response.

Note that NAPTR is not that widely implemented. So you might want to
make sure that DNS lookup for the MIH server can work without using
NAPTR.

Vijay

> In the example you gave you made the assumption that the domain hosts 
> an mih service using udp.
> 
> - gabor
> 

> something like "_mih._udp.example.com". You would then set aside a new

> SRV record for the above label. Then the mobile node would be