Re: DNS issue with LAN WAN config

sukhjits8511 · ‎03-30-2005

Hi all cisco gurus....

am facing a very peculiar problem with a LAN and WAN setup on cisco 2611 XM 12.3 (13) IP+.

i have attached the link to the internet cloud on the serial interface.

and LAN attached to the FE 0/0.

I am able to ping site like yahoo and google etc from the router and from the LAN( PC) also.

But the sites are not opening on the PC's, am able to ping and trace successfully from the PC's to various internet site.

If i give the ip of the site in the browser it opens but not with the name.......

what to do ....kindly help

tekha · ‎03-30-2005

You say that you are able to ping from the router, but are you pinging by name or IP?

If it works på pinging by name, are you using the same DNS server on the router as on your PC?

Try and do a "nslookup" from the PC, to eg. www.yahoo.com, does that work?

barisal · ‎03-30-2005

If you send to us the related config on the router and the IP condif of the PC that you test from, it will be better for us to undestand the issue.

Regards,

sukhjits8511 · ‎03-30-2005

Hi...nice to see your replies ppl

i am able to do nslookup yahoo.com from the pc, the site opens from the pc with the ip of yahoo in the IE but not with the name, am using the same DNS in pc as in router.

-----------------------------------------------

ip name-server *.*.12.42

interface FastEthernet0/0

ip address *.*.222.161 255.255.255.0

ip route-cache flow

duplex auto

speed auto

interface Serial0/0

ip address *.*.228.238 255.255.255.252

ip accounting output-packets

no ip route-cache

no ip mroute-cache

ip route 0.0.0.0 0.0.0.0 Serial0/0

ip route *.*.222.160 255.255.255.0 FastEthernet0/0

----------------------------------------------------

PC config

ip *.*.222.162

Mask 255.255.255.0

Gw *.*.222.161

DNS *.*.12.42

kindly guide me how to troubleshoot this problem

cool.cisco · ‎03-30-2005

Hi,

Are you using any firewall in between????

I think no...

What i would suggest you is to add more entries of dns server and change the DNS server,,if you are in india try to use primus dns or vsnl dns server as a primary.

Moreover the problem seems to be on the application layer..

Any by chance any ACL you have applied?????

Let us know if it resolves the issue...

barisal · ‎03-30-2005

As fas as i have understood, the PC IPconfig is hard-configured. Try to use dhcp that is configured on the router. Your IOS is quite new and support these kind of configurations. I have gone through the bug tool-kit and could not find any bugs related to your problem. I think there is not any problem telneting to web site in port 80 by giving source address of the ethernet of the router, in other words the default gateway of the router. Let router distribute the DNS server to clients in the LAN. By the way, is it a cross-cabled connection or is there a kind of hub or switch connection ? And also it may be helpfull to check the network interface card settings installed on the clients.

Let us know the result.

Example of configuration...

ip name-server x.x.x.x

Please define a secondary that is generally recommended.

ip dhcp excluded-address *.*.222.161

ip dhcp excluded-address *.*.222.162

ip dhcp pool CLIENT

network *.*.222.160 255.255.255.0

default-router *.*.222.161

dns-server x.x.x.x y.y.y.y ......

!

tekha · ‎03-31-2005

Well, let me just summarize.

You are able to ping, by name, www.yahoo.com, from the PC.

And you are able to surf the web in IE, but by IP address only, NOT by name.

Correct?

It would seem that this is a problem with IE not using the DNS server, to make name lookups, why it's a problem I don't know, but could you try with another PC?