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DNS service for AREDN clients

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W6JMK
DNS service for AREDN clients

Is it practical to provide DNS service within an AREDN mesh? I mean something similar to dynadot or namecheap, where people can publish mydomain.com or yourdomain.com, MX records for their domain, SPF and DKIM records etc. and anyone can refer to them conveniently. Of course, the published names would resolve to mesh 10.x IP addresses. It seems clear someone could host a DNS server, but I don't know how users would configure their DNS clients.

For example, consider a laptop whose only connection is to a Ubiquiti NanoStation. Could its Microsoft Mail client be configured to send email to smtp.my-city-races.org (which identifies an SMTP server connected to an AREDN node)?

K6CCC
K6CCC's picture
It already exists

Unless I'm missing something - that already exists.  Your hypothetical laptop would be getting a DHCP address from the attached AREDN node.  Included in the DHCP information is that the local node should operate as the DNS provider for that laptop.  The node will be able to resolve any AREDN device or advertised service from OLSR data, and therefore be able to pass along DNS resolution to the laptop when requested.  There is no need to run a mail server with a .com address.
 

W6JMK
DNS service for AREDN clients
DNS service for AREDN clients

For the sake of discussion, let's assume there is a need to handle email addressed to @mydomain.org. Is this practical?

A suitably configured DNS server can resolve MX records for mydomain.org, which will enable MTAs to forward mail to the right server. But how would clients know to query that DNS server, instead of (or in addition to) the server in their node? As far as I know, the DNS server in a node only resolves .local.mesh names, and can't handle MX records at all.
K6CCC
K6CCC's picture
As far as I know, the DNS

As far as I know, the DNS server in a node only resolves .local.mesh names, and can't handle MX records at all.

As far as I know,that is correct that the node will only resolve .local.mesh address.  Why do you need to resolve some other domain?
As far as MX records, there are mail servers all over the mesh that work fine, so I am going to assume that they are able to get MX records.

 

W6JMK
there are mail servers all

there are mail servers all over the mesh that work fine, so I am going to assume that they are able to get MX records.

That would be useful. How can I publish MX, SPF or TXT records for my server?
K6CCC
K6CCC's picture
I don't run a mail server (at
I don't run a mail server (at least not on the mesh), so I can't answer that question.
 
nc8q
nc8q's picture
TLD not supported in Advertised Services

Top Level Domains are not supported. No .com, .org, .net, ...
By default names must be alphanumeric or hyphen or underscore.
Likely names beginning with hyphen or underscore are not allowed.
The domain .local.mesh is automatically appended.
So, AREDN will not support mydomain.com, yourdomain.com, or smtp.my-city-races.org .
However, in workstations connected to the local AREDN network may alter their /etc/hosts file as
smtp.my-city-races.org w6jmk-smtp-server w6jmk-smtp-server.local.mesh

I hope this helps,
Chuck
 

W6JMK
Someone suggested
Someone suggested reconfiguring clients' nodes. Specifically, it might be possible to telnet into a node and edit /etc/dnsmasq.conf, to cause the node to fetch information from DNS servers elsewhere in the mesh. I think I'll give that a try.
km6zpo
km6zpo's picture
External Email via AREDN
Hello I have a mail server on the mesh.  I can send to accounts on other mail servers connected to the mesh.  Email addreses on the mesh appear like:

{account name}@{host}.local.mesh

My mail server is connected to the external Internet.  If I send an email to an external address, the mail server will forward it out.  However, that would be coming from a MESH address (as per the above addressing).  So if an external account wanted to respond, it would go nowhere.  Mesh addreses are not part of the greater Internet.

What you need is a mail server which can handle external and internal addressing automatically.  On a server like that, every account interacting with the outside world would have a primary email address as the Internal and an Alias as the external.  The server would need to automatically re-format your return email address for outbound emails and again for inbound emails. 

I'm not aware of any such email server.  One probably exists, I just haven't heard of it. 

Hope that helps at least on the mail server side of things.
 
W6JMK
DNS service for AREDN clients

I aim for users to have a single email address, which works both inside the mesh and outside in the public Internet. I've made this work for a single email server (w6jmk-postoffice in the SFWEM). But to exchange email between different servers within the mesh, better DNS service is wanted. The problem is also described here.

... every account interacting with the outside world would have a primary email address as the Internal and an Alias as the external.  The server would need to automatically re-format your return email address for outbound emails and again for inbound emails.

W6JMK
DNS service for AREDN clients
DNS CNAME records would (arguably) be better than tactical call signs.
W6JMK
DNS service for AREDN clients
It is possible to configure a node to forward DNS queries to name servers elsewhere in the mesh. For example, the attached package dnsmore does this. (Its source code is here.) A standard Bind9 name server works fine, and it can be administered by multiple domain owners using nsupdate.

But I'm not sure this is practical. I've noticed that the node forwards DNS queries to a name server quite frequently. Most of them come from Windows computers attached to the node. The name server responds quickly. Most of the queries are for names in the public Internet, to which the name server responds with Refused. It's a fair amount of traffic, which would be sent over inter-node microwave links in a realistic situation. I fear it would clog up the inter-node links.
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