Posts: 3
Registered: ‎10-03-2012

Blocked DNS (WAN) - Linksys E1200 (Wireless N300 Router)

My SoHo network is configured as follows -

  •       CenturyLink DSL Service
  •       Zyxel PK5000z DSL Modem (configured with Class A static IP Address Block)
  •            2 Server Hosts using Static IP addresses
  •            Dedicated Gateway, Subnet Mask, DNS primary/secondary hosts
  •       Linksys E1200 Wireless Router
  •            DHCP / NAT enabled for Wireless Access
  •             Supports 192.168.x.x private addressing

The problem with WAN access is described here -

  •    All devices are cabled into the DSL Modem Ethernet Ports
  •    When using both Private/Public Address, only one Server with Static IP can access the Internet
  •          Wireless Router is Active
  •          2nd server with Static IP is blocked
  •     When the Linksys E1200 Router is unplugged, both servers get to the Internet

Troubleshooting - I have tinkered with the following options

  •    DSL Modem in Bridge Modem (all routing thru the LinkSys router)
  •          Will be testing this again in the future
  •    Different DNS settings on the LinkSys 1200E router (Automatic vs Manual Primary/Secondary addresses)
  •    Traceroute - As soon as the LinkSys router is detached, traceroute from servers works fine

Advise/Comments Welcome



Posts: 1,644
Registered: ‎05-04-2012

Re: Blocked DNS (WAN) - Linksys E1200 (Wireless N300 Router)

Since your modem is already set to bridge mode, try to disable block anonymous internet requests/filter anonymous requests on the router. What are the static ip addresses you have assigned for your servers? It is possible that there is a conflict between the two or might be within the DHCP client server range.

Posts: 3
Registered: ‎10-03-2012

Re: Blocked DNS (WAN) - Linksys E1200 (Wireless N300 Router)

The DSL Modem is not currently in 'Bridged Mode'.  It is set to 'PPPoE'.

I will look at 'Block Anonymous Internet (disable). on the router.

The Class A static IP addresses (on servers) are not in the router's Wireless DHCP range (192.168.x.x).


The latest anomaly (spotted today) is that an external HTTP call to one of the servers (Public IP addresses)

running the HTTPD process is to route this request to the Admin Interface on the Router (referenced by the

Static IP address).  This is plain weird.


If I had to summarize the problem (high level) -

   In competing for IP/Internet address space, a LinkSys Router behind a DSL modem interferes with normal processing.

   Maybe the 1200E router is too 'low end' to handle this effectively.

   Alternatively, maybe the router wants to be the sole communication device on the SoHo NW (requiring DSL modem to

       be in 'transparent bridge' mode.



Posts: 3
Registered: ‎10-03-2012

Re: Blocked DNS (WAN) - Linksys E1200 (Wireless N300 Router)

Problem solved (DNS that is).  The Admin interface to the E1200 shows that 'Internet Connection' had the following configuration -


Connection Type - DHCP

Internet IP Address - (Conflicting with Service Class A address)


When I changed the Server Address, I was back in business.

Which brings up the questions -

        'What is this setting on the router'

        'What are the functions 'Release IP/Renew IP Address' about?


Simple answer might be that the E1200 uses one of the Class A addresses.

This might explain why the attempt at an 'http' call (Class A address) went to the Admin window.


Sorry if this sounds a bit muddled but I've been in trial and error mode for some time now.



Posts: 1,206
Registered: ‎05-04-2012

Re: Blocked DNS (WAN) - Linksys E1200 (Wireless N300 Router)


I see. Have you tried updating the fw of the router?