[Dnsmasq-discuss] dnsmasq for road warriors
Seems to me that dnsmasq is a better nscd replacement, and it has a place in mobile computing. # we use this dnsmasq as this system's own resolver no-resolv # I'm not sure if both of these are needed; we only want DNS and # only on loopback; we serve only this machine. no-dhcp-interface=lo listen-address=127.0.0.1 user=dnsmasq group=dnsmasq # When connected to VPN, these names/addresses resolve. When not # connected, they don't, but that's okay, because we can't get to # them anyway. server=/rob0.vpn/192.168.6.1 server=/6.168.192.in-addr.arpa/192.168.6.1 # upstream: Google Public DNS server=8.8.4.4 The problem here is when you might not want to use 8.8.4.4, such as when you're at a dnsmasq site where internal DNS is working. The solution, I guess, would be a hook in the DHCP client to write the DHCP-obtained nameserver[s] to a dnsmasq.d/file to include, and signal or restart dnsmasq. Problem with that solution: will dnsmasq.d get crufty, or do we just reuse the same file? Also, what if one of the mobile connections is not handled by DHCP, such as some cellular data connections? Speaking of cruft, maybe that's not a bad thing? What will dnsmasq do with multiple upstream servers? server=192.168.40.1 server=192.168.0.1 server=192.168.1.1 server=8.8.4.4 When we're at a site where one of those is our router, that should respond much faster than 8.8.4.4 can. OTOH, it could cause intermittent errors with local names; 8.8.4.4 is not going to know minipax.rob0.lan. Can we priortise upstream servers? --all-servers implies that this can be done somehow, but I don't know how ... is it merely the order in which they are listed in the config (or on the command line)? When not using --all-servers, how does dnsmasq decide when to try a different one, and which one will be tried in that case? Random selection, rotating sequential, fixed top-down priority? Ideally we'd want something which you set up one time and is mostly done; something that should work at regular sites you frequent, as well as most public hotspots. -- http://rob0.nodns4.us/ -- system administration and consulting Offlist GMX mail is seen only if /dev/rob0 is in the Subject: ___ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
[Dnsmasq-discuss] DNS mapping for a specific IP
I need to do following DNS mapping in my router for all requests coming from a specific computer/IP- 192.168.2.2amazonaws.com This mapping should not be done for requests coming from other computers in my network. Currently I have defined it in my router (DDWRT) using dnsmasq but it is applicable for all computers in my network. The computer that I want to restrict this mapping for is a wireless photo frame. I don't have access to its /etc/hosts file. That's why I need to do it at the router level. Is this possible in standard dnsmasq? If not, is it possible to do it with some small code change in dnsmasq? Thanks, Karina.___ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
Re: [Dnsmasq-discuss] DNS mapping for a specific IP
You could use iptables to redirect DNS queries from that photo frame to an alternate dnsmasq instance, via port masquerade. On Sat, Nov 10, 2012 at 9:58 AM, Karina Goyal karinago...@yahoo.com wrote: I need to do following DNS mapping in my router for all requests coming from a specific computer/IP- 192.168.2.2amazonaws.com This mapping should not be done for requests coming from other computers in my network. Currently I have defined it in my router (DDWRT) using dnsmasq but it is applicable for all computers in my network. The computer that I want to restrict this mapping for is a wireless photo frame. I don't have access to its /etc/hosts file. That's why I need to do it at the router level. Is this possible in standard dnsmasq? If not, is it possible to do it with some small code change in dnsmasq? Thanks, Karina. ___ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss ___ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
[Dnsmasq-discuss] dnsmasq acts as the DHCP server for selected nodes overriding the existing DHCP server on the same LAN?
I am trying to set up a small lab in my home. Like many homes, I have a
regular DSL service which comes with a 2Wire 3600HGV router, which acts also as
a DHCP server. Since
* I would like to PXE boot a few computers in my lab
* The 2Wire is flexible
* I have used dnsmasq at work
so I would like to use dnsmasq as the DHCP server for the few nodes in my lab
if feasible.
Checking the man page at
http://www.thekelleys.org.uk/dnsmasq/docs/dnsmasq-man.html, there is the
following:
[...]
-K, --dhcp-authoritative
(IPv4 only) Should be set when dnsmasq is definitely the only DHCP server
on a network. It changes the behaviour from strict RFC compliance so that DHCP
requests on unknown leases from unknown hosts are not ignored. This allows new
hosts to get a lease without a tedious timeout under all circumstances. It also
allows dnsmasq to rebuild its lease database without each client needing to
reacquire a lease, if the database is lost.
[...]
As far as I know, the ISC DHCP server can use the following to do what I would
like to accomplish:
authoritative;
[...]
subnet 192.168.1.0 netmask 255.255.255.0 {
host nb0 {
# 'ping target_host', 'arp' shows MAC address
# only give DHCP information to this computer:
hardware ethernet e8:9a:8f:17:70:42;
# Basic DHCP info (see 'ifconfig', 'route', 'cat /etc/resolv.conf')
fixed-address 192.168.1.10;
option subnet-mask 255.255.255.0;
option routers 192.168.1.254;
option domain-name-servers 192.168.1.254;
# Non-essential DHCP options
filename /pxelinux.0;
}
[...]
But I much prefer dnsmasq's all-in-one-ness. My question: do I have to
couple the -K option with something else? As shown in the example above, the
ISC DHCP server requires the mac addresses of managed nodes to be explicitly
specified. Does dnsmasq have something similar?
Regards,
-- Zack
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