1811 Internet Router - DNS Setup

[darrenkmurray]

Hello,

I have an 1811 which is setup as an Internet router for about 20 users.  FastEthernet0 is connected to the ISP and is assigned a static IP. 

I also assigned a static route to the ISP gateway.  I want the users to get an IP, subnet mask, gateway and DNS addresses via DHCP from the router. The snippets below from the config refer.  DHCP is working fine and I can ping public addresses from machines on the private side of the router.  I cannot however ping by name directly from the router itself, and Internet surfing is hopelessly slow. It seems much better if I enter IP addresses into the browser bar instead of URLs so I'm thinking the DNS setup is not right.  Is this the typical way of setting up an Internet router, or do I have this completely wrong?  Any suggestions are much appreciated.  The complete config is attached for reference.  Thx.

interface FastEthernet0

description SHAW Internet WAN Connection$ETH-WAN$

ip address 208.118.89.38 255.255.255.240

ip nat outside

ip virtual-reassembly

duplex auto

speed auto

ip dhcp pool TCU_INT

   import all

   network 192.168.7.0 255.255.255.0

   default-router 192.168.7.1

   dns-server 64.251.87.194 66.244.223.130

   lease 0 5

interface Vlan2

description TCU Internal Internet$ES_LAN$

ip address 192.168.7.1 255.255.255.0

no ip unreachables

ip nat inside

ip virtual-reassembly

ip forward-protocol nd

ip route 0.0.0.0 0.0.0.0 FastEthernet0 permanent

ip route 0.0.0.0 0.0.0.0 208.118.89.33

[Brunhuber Adrian]

The router has nothing to do with resolving the name of a website.It just routes packets to dns servers who perform this translation.If you suspect a dns problem try changing the dns servers in the dhcp pool use for test dns servers 8.8.8.8 and 4.2.2.2.

To test the quality of the conection use a repetead ping " ping repeat on a ip of your choise.

To make the router resolve names enter "ip name-server x.x.x.x" where x.x.x.x is a dns server.

Also try removing the "ip route 0.0.0.0 0.0.0.0 FastEthernet0 permanent" and leave only "ip route 0.0.0.0 0.0.0.0 208.118.89.33" if 208.118.89.33 is the default gateway provided by your ISP.

Let me know how things works.

[cadet alain]

Hi,

You could configure your router as a cache-only dns server but I don't think this would better your performances especially if your clients are windows xp or higher because they have a dns cache already.

Here is a link http://www.nil.com/ipcorner/RouterDNS/

But as Adrian just remarked removing the first static default route will certainly improve things because a static route pointing to a multimedia interface like ethernet or frame-relay will make the router arp for every destination as he thinks they are all located on this link and if the next-hop hasn't got proxy-arp enabled( for ethernet) it will give you incomplete entries in the arp cache,if proxy-arp is enabled then your arp-cache will get very big because for every destination you're trying to reach you'll have an arp mapping pointing to next-hop mac address.In the case of frame-relay it won't ever work because the doesn't exist such thing as proxy inverse-arp.

Don't forget to clear arp cache after removing the route to the interface with clear arp command.

Regards.

Alain.

[darrenkmurray]

Thanks for the help folks. I'll try your suggestions tomorrow and see how it goes.