some websites work others dont 1841 router

[chomiczmichael]

hello!

just configured a 1841 router and im trying to figure out why some websites work and others dont - when i put in a small TP-LINK everything works fine so its not my ISP - any suggestions?

my config:

Building configuration...

Current configuration : 3057 bytes
!
version 12.4
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname RT1841
!
boot-start-marker
boot-end-marker
!
logging message-counter syslog
enable secret 5 $1$nRsK$6JevOfdqAjpN5Ak/190jF1
!
no aaa new-model
!
ip source-route
!
!
ip dhcp database DHCP_POOL
ip dhcp excluded-address 10.0.0.1
!
ip dhcp pool DHCP_POOL
   network 10.0.0.0 255.255.255.128
   domain-name chomiczki.com
   dns-server 10.0.0.1
   default-router 10.0.0.1
   lease 7
!
ip cef   
no ipv6 cef
!
multilink bundle-name authenticated
!
vpdn enable
!
vpdn-group home
request-dialin
  protocol pppoe
!
!
!
!
!
!
spanning-tree vlan 666 priority 0
archive
log config
  hidekeys
!
!
!
!        
!
!
!
!
interface FastEthernet0/0
ip address 192.168.1.2 255.255.255.0
duplex auto
speed auto
!
interface FastEthernet0/1
description ADSL WAN interface PPOE
mtu 1410
no ip address
no ip redirects
no ip unreachables
no ip proxy-arp
ip nat outside
ip virtual-reassembly
no ip mroute-cache
duplex auto
speed auto
pppoe enable group global
pppoe-client dial-pool-number 1
no cdp enable
!
interface FastEthernet0/0/0
switchport access vlan 666
!
interface FastEthernet0/0/1
switchport access vlan 666
!
interface FastEthernet0/0/2
switchport access vlan 666
!
interface FastEthernet0/0/3
switchport access vlan 666
!
interface Vlan1
no ip address
!
interface Vlan666
ip address 10.0.0.1 255.255.255.128
ip nat inside
ip virtual-reassembly
!
interface Dialer1
description Wan Dialer
mtu 1492

ip address negotiated
no ip unreachables
ip nat outside
ip virtual-reassembly
encapsulation ppp
no ip mroute-cache
dialer pool 1
dialer-group 1
no cdp enable
ppp authentication chap pap callin
ppp chap hostname xxxxxxxxxxxxxx

ppp chap password 0 xxxxxxxxxxxxx
ppp pap sent-username xxxxxxxxxxxxxxx password 0 xxxxxxxxxxxx

ppp ipcp dns request
ppp ipcp route default
!
ip forward-protocol nd
ip route 0.0.0.0 0.0.0.0 Dialer1
no ip http server
no ip http secure-server
!
!
ip dns server
ip nat inside source list 10 interface Dialer1 overload
!
access-list 10 permit 10.0.0.0 0.0.0.255
no cdp run

!
!
!
!
!
!
control-plane
!
!
!
line con 0
line aux 0
line vty 0 4
password xxxxxxxxxxxxxx

login
!
scheduler allocate 20000 1000
end

[sean_evershed]

Hi,

What sort of error message do you get?

As a test can you try changing your DNS to point to one of the publicly available DNS servers like Google? See below:

http://code.google.com/speed/public-dns/

[chomiczmichael]

hi sean

the pages take extremely long to load - didnt wait long enough to give an error - i've already tried the google dns servers too.. but like i said - i throw in a small TP-LINK router in and same pages go quick

[Kishore Chennupati]

hi Michael,

I believe this is to do wit MTU settings on your router. I have made some suggestions. can u please try and see if it works?

after the below changes if it still doesnt work then please try to lower the mtu value on the dialer interface to a lower value till you are able to get to all the websites.

interface FastEthernet0/0
 ip address 192.168.1.2 255.255.255.0
 duplex auto
 speed auto
!
interface FastEthernet0/1
 description ADSL WAN interface PPOE
 mtu 1410                                                  <<<
 no ip address

interface Dialer1
 description Wan Dialer
 mtu 1492                                        <<
 ip address negotiated
 no ip unreachables
 ip nat outside

HTH,

Regards,

Please rate if helpful

[chomiczmichael]

thanks for the suggestion - i've made the changes - even set the ip mtu to 1410 but still no good

[Kishore Chennupati · Accepted solution]

hi Michael,

chomiczmichael wrote:
thanks for the suggestion - i've made the changes - even set the ip mtu to 1410 but still no good 

I am not sure where you are getting the 1410 figure from? Did you remove it from the fa0/1 though? ok can u please set the  ip mtu  on the dialer interface to 1492 and also on the fa0/0 put in   "ip tcp adjust-mss 1452" .

Also, on that TP LINK modem router you were using, did you check what mtu is that set to?

Regards,

[chomiczmichael]

hi kishore

the f0/1 isnt connected to anything - i have a 4 port hwic card installed on the router - i have added the ip tcp adj 1452 on the vlan interface and everything is working fine now

thanks for your help