Problem with dnsmasq that I can't find a solution for

Post new topic   Reply to topic    DD-WRT Forum Forum Index -> Broadcom SoC based Hardware
Author Message
DD-WRT Novice

Joined: 29 Oct 2013
Posts: 1

PostPosted: Tue Oct 29, 2013 18:21    Post subject: Problem with dnsmasq that I can't find a solution for Reply with quote
Okay so, I currently have a very simple network. A linksys e1500 with dd-wrt on it, with some devices hooked up to it, including another wireless router functioning as an AP.

As long as I don't use dnsmasq, everything functions hunky-dory. But I would like to have local hostname resolution. From what I have read, the best way to do this means using dnsmasq for both dhcp and dns.

Whenever I turn dnsmasq on for dhcp and dns my computer can no longer obtain an ip address from the router, and no longer has access to the internet (Comcast).


Setup > Router IP->
Local IP Address:
Subnet Mask:
Local DNS:

Setup > Network Address Server Settings (DHCP)->
DHCP Type: DHCP Server
DHCP Server: Enabled
Start IP Address:
Maximum DHCP Users: 100
Static DNS 1:
Static DNS 2: (opendns)
Static DNS 3: (opendns)
Use DNSMasq for DHCP: Enabled
Use DNSMasq for DNS: Enabled
DHCP-Authoritative: Tried both

Services > DHCP Server->
Use JFFS2 for client lease DB:(Not mounted)
Use NVRAM for client lease DB: Disabled
Used Domain: LAN & WLAN
LAN Domain: lan
Additional DHCPd Options: none

Services > DNSMasq->
DNSMasq: Enabled
Local DNS: Tried both
No DNS Rebind: Enabled
Additional DNSMasq Options:
I've tried a few things here, but its my understanding that I should probably have "strict-order" and possibly "local=/lan/"

I also have many reserved static IPs for addresses under, including one for my PC, specifically

Hardware: Linksys E1500
Firmware: DD-WRT v24-sp2 (03/25/13) big

1) everything works
2) I save the settings as seen above
3) I do "ipconfig /release" and "ipconfig /renew", but the renew fails complaining about not being able to access a file for a loopback interface
4) I lose all network connectivity
5) I set my PC's IPv4 statically to
6) I now can reach the router, but not the internet
7) I then put the configuration back to the way it was when it worked, reset my IPv4 to dynamic, do a /release/renew, and I have internet again.


Random observation:
When all is working my ipconfig /all has a Connection-specific DNS Suffix ending in "" rather than "lan". Dunno if its important.
Max Hopper
DD-WRT Novice

Joined: 28 Jun 2013
Posts: 20

PostPosted: Mon Apr 14, 2014 14:02    Post subject: Who moved my cable? Reply with quote
Indeed, dnsmasq 'solves' the problem of how to resolve local hostnames and DHCP leases all in one go.

N.B. many WAN modem/router devices do not offer a DNS service. DHCP clients are displayed in the web GUI of the WAN modem. This is not a local DNS

In which router Ethernet port is the cable to the WAN modem? A LAN and not the WAN port?

Without modification to the OOTB dd-wrt setting Setup | Basic Setup | WAN Setup | WAN Connection Type |
Connection Type <Automatic Configuration - DHCP>
NAT is active only on the router WAN port. And when the LAN side address of the WAN modem is not in the subnet selected by Setup | Basic Setup | Network Setup | Router IP | Local IP Address <> IP packets from the LAN side of the WAN modem have no path to the router.

To overcome the subnet mismatch:
    alter the LAN address of the WAN modem <192.168.1.(2-154)>
    disable the DHCP server of the WAN modem lest there be two DHCP servers randomly handling DHCP DISCOVER requests
    -- or --
    move the WAN modem <-> router cable to the router WAN port

N.B. moving the WAN modem <-> router cable to the router WAN port effects 'double NATting' (unnecessary overhead)
Display posts from previous:    Page 1 of 1
Post new topic   Reply to topic    DD-WRT Forum Forum Index -> Broadcom SoC based Hardware All times are GMT


Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You can attach files in this forum
You can download files in this forum