OT: Getting local IP addresses from a gateway

[Jonathan Ryshpan]

I need to get the IP numbers of local hosts, i.e. hosts inside my
gateway's firewall.  The domain name server in the gateway provides the
IP addresses of hosts and sites on the internet, but does not provide
the IP addresses for hosts on my local net.  The gateway is aware of
their names and addresses; one of its admin screens shows them, exactly
as they identify themselves.  A chat session with customer support (an
extract follows) indicates that this function is definitely not
available.  The problem is not disastrous, since the addresses, once
assigned, are pretty much static, and so can be put into /etc/hosts.
However this looks a little like a hack.  

Has anyone else dealt with this problem?  Know a way around it?  Do
gateways from other manufacturers have similar problems?

On the one hand, I'm pleased to get a straight answer, even though bad
news, from Belkin.  On the other I'm amused that after telling me that
this particular function of the router is totally broken, the tech rep
thanks me for choosing Belkin.

Router is Belkin  F7D5301 v1 (01)
System is Fedora-16 on x86_64 hardware

============ Chat Session (edited) Follows ============
...
jonrysh: ... This router (and all your other routers) will not return
the IP address belonging to a host that it knows about in reply to  any
kind of query from a host (except the admin interface). Is this correct?
Belkin: thats correct
jonrysh: Thanks very much. We are complete.  Bye
Belkin: Thank you for choosing Belkin technical support have a nice day

[Reindl Harald]

Am 23.04.2012 00:09, schrieb Jonathan Ryshpan:
>  I need to get the IP numbers of local hosts, i.e. hosts inside my
> gateway's firewall.  The domain name server in
>  the gateway provides the IP addresses of hosts and sites on the internet, but does not
> provide the IP addresses for
>  hosts on my local net.  The gateway is aware of their names and addresses; one of its
> admin screens shows them,
>  exactly as they identify themselves.  A chat session with customer support (an extract
> follows) indicates that this
>  function is definitely not available.  The problem is not disastrous, since the
> addresses, once assigned, are
>  pretty much static, and so can be put into /etc/hosts.  However this looks a little like
> a hack.  
have you ever heard about DNS? :-)

[Jonathan Ryshpan]

On Mon, 2012-04-23 at 00:15 +0200, Reindl Harald wrote: 

>  Am 23.04.2012 00:09, schrieb Jonathan Ryshpan:
>  > I need to get the IP numbers of local hosts, i.e. hosts inside my gateway's
> firewall.  The domain name server in
>  > the gateway provides the IP addresses of hosts and sites on the internet, but does
> not provide the IP addresses for
>  > hosts on my local net.  The gateway is aware of their names and addresses; one of
> its admin screens shows them,
>  > exactly as they identify themselves.  A chat session with customer support (an
> extract follows) indicates that this
>  > function is definitely not available.  The problem is not disastrous, since the
> addresses, once assigned, are
>  > pretty much static, and so can be put into /etc/hosts.  However this looks a little
> like a hack. 
>  
>  have you ever heard about DNS? :-) 
I have.  The gateway includes a mini DNS server within itself, as you
probably know.  I could set up a DNS server on one of my hosts, but
don't think this would be worth the trouble, since there will be at most
4 of them.  Thanks for your advice, which is well meant though
mischievously stated (;-).

jon

[Mikkel L. Ellertson]

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On 04/22/2012 08:11 PM, Jonathan Ryshpan wrote:
>  On Mon, 2012-04-23 at 00:15 +0200, Reindl Harald wrote:
> > Am 23.04.2012 00:09, schrieb Jonathan Ryshpan:
> > > I need to get the IP numbers of local hosts, i.e. hosts inside 
my
gateway's firewall. The domain name server in
> > > the gateway provides the IP addresses of hosts and sites on
> the 
internet, but does not provide the IP addresses for
> > > hosts on my local net. The gateway is aware of their names
> and 
addresses; one of its admin screens shows them,
> > > exactly as they identify themselves. A chat session with
customer support (an extract follows) indicates that this
> > > function is definitely not available. The problem is not
disastrous, since the addresses, once assigned, are
> > > pretty much static, and so can be put into /etc/hosts.
> However 
this looks a little like a hack.
> >
> > have you ever heard about DNS? :-)
>  I have. The gateway includes a mini DNS server within itself, as 
you probably know.
I could set up a DNS server on one of my hosts,
but don't think this would be worth the trouble, since there will be
at most 4 of them. Thanks for your advice, which is well meant
though mischievously stated (;-).
>  jon
>  
With that few hosts, you may want to have your router assign
specific IP address to each MAC address, so that they are always the
same, and use the host file as you stated. I have not checked the
specifications for your router, but most will let you assign a
static IP address in the DHCP setup. The only drawback is that if
you change NICs, you have to modify the settings in the router, or
change the configuration on the computer so it uses the old MAC
address...

Mikkel
- -- 
Do not meddle in the affairs of dragons, for thou art crunchy and
taste good with Ketchup!
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[Scott Doty]

Not sure if you can run it on the belkin, but dd-wrt has this capability...

Also, using avahi, you might be able to resolve the host as "hostname.local"
(where "hostname" is your host's name.

Finally, when all else fails, you can always serve up the in-addr.arpa zones for your
private address space. :-)

-- 
Sent from my Android phone with K-9 Mail. Please excuse my brevity.

Jonathan Ryshpan <jonrysh(a)pacbell.net&gt; wrote:

I need to get the IP numbers of local hosts, i.e. hosts inside my gateway's firewall. 
The domain name server in the gateway provides the IP addresses of hosts and sites on the
internet, but does not provide the IP addresses for hosts on my local net.  The gateway is
aware of their names and addresses; one of its admin screens shows them, exactly as they
identify themselves.  A chat session with customer support (an extract follows) indicates
that this function is definitely not available.  The problem is not disastrous, since the
addresses, once assigned, are pretty much static, and so can be put into /etc/hosts. 
However this looks a little like a hack.  

Has anyone else dealt with this problem?  Know a way around it?  Do gateways from other
manufacturers have similar problems?

On the one hand, I'm pleased to get a straight answer, even though bad news, from
Belkin.  On the other I'm amused that after telling me that this particular function
of the router is totally broken, the tech rep thanks me for choosing Belkin.

Router is Belkin  F7D5301 v1 (01)
System is Fedora-16 on x86_64 hardware

============ Chat Session (edited) Follows ============
...
jonrysh: ... This router (and all your other routers) will not return the IP address
belonging to a host that it knows about in reply to  any kind of query from a host (except
the admin interface). Is this correct?
Belkin: thats correct
jonrysh: Thanks very much. We are complete.  Bye
Belkin: Thank you for choosing Belkin technical support have a nice day

[Ian Malone]

On 23 April 2012 00:08, Scott Doty <scott(a)ponzo.net&gt; wrote:

>  Jonathan Ryshpan <jonrysh(a)pacbell.net&gt; wrote:
> >
> > I need to get the IP numbers of local hosts, i.e. hosts inside my
> > gateway's firewall.  The domain name server in the gateway provides the IP
> > addresses of hosts and sites on the internet, but does not provide the IP
> > addresses for hosts on my local net. 
>  Not sure if you can run it on the belkin, but dd-wrt has this
> capability...
>
>  Also, using avahi, you might be able to resolve the host as "hostname.local"
>  (where "hostname" is your host's name.
>  
Agreed, you should be able to install nss-mdns and avahi on all your
machines and then use hostname.local addresses. I don't know how you
get Mac and Windows to play with this configuration (Mac at least
should be able to do it) and if there are non-pc devices that need to
be resolved then you do need to think about having a DHCP+DNS server
or giving those static-IPs for your network (which is not necessarily
a bad solution).

-- 
imalone
http://ibmalone.blogspot.co.uk

[Tim]

On Sun, 2012-04-22 at 15:09 -0700, Jonathan Ryshpan wrote:
>  I need to get the IP numbers of local hosts, i.e. hosts inside my
>  gateway's firewall.  The domain name server in the gateway provides
>  the IP addresses of hosts and sites on the internet, but does not
>  provide the IP addresses for hosts on my local net. 
It's quite common for domestic routers to not bother with reverse name
lookups as well as forward ones (since the average user won't need the
feature, there's little incentive for them to include it).

Long ago, I decided that if I wanted a name resolution on my LAN, that I
should run a local name server on one of the computers, rather than let
a modem/router do a half-assed job.  So I went the whole hog.  I turned
off the DHCP server in the router, and ran one in the server PC, along
with a DNS server on the server that talked to the DHCP server.

Permanent machines get doled out the same IP by the DHCP server, and the
DNS server resolves their addresses in both directions (*).  Visiting
machines get doled out a temporary IP, their addresses are temporarily
entered into the DNS server recorded, and their addresses are resolved
in both directions.  And my DNS, also, resolves all queries about WWW
addresses for the LAN PCs.

I've never regretted doing so.  I appreciate it all the more for being
able to kill some addresses through my name server (any lookups related
to them fails - doubleclick.com doesn't work, at all, now; likewise with
many other annoyances).

* "Both directions" meaning that a forward lookup of asking for the IP
for an name, and a reverse lookup of a name for an IP, both work.

-- 
[tim@localhost ~]$ uname -r
2.6.27.25-78.2.56.fc9.i686

Don't send private replies to my address, the mailbox is ignored.  I
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