2960-X Switch DNS Issue

[CSCO12001340]

Hi,

I set up a new Cisco 2960-X to a new location but faced with a strange problem.

IP connectivity was great, all pings were succesful for the remote locations. But users were not able to surf on internet for some web sites (i.e. google, yandex was ok but any other web sites were not ok)

I never tought that this is a Layer-2 problem. Problem was fixed by changing with a Juniper switch.

On Cisco switch, I am just using a dhcp relay which is forwarding all requests to the DHCP server.

What can be the problem ?

[Deepak Kumar]

Please share switch configuration.

Regards,
Deepak Kumar

[CSCO12001340]

Hello,

Here is the config :

version 15.2
no service pad
service timestamps debug datetime msec show-timezone
service timestamps log datetime msec localtime
service password-encryption
service sequence-numbers
!
hostname sw
!
boot-start-marker
boot-end-marker
!
logging buffered 100000 notifications
!
no aaa new-model
clock timezone IST 2 0
clock summer-time TR recurring last Sun Mar 3:00 last Sun Oct 4:00
switch 1 provision ws-c2960x-24ps-l
!
!
ip domain-name my.ic
!
!
!
spanning-tree mode pvst
spanning-tree extend system-id
!
!
!
!
vlan internal allocation policy ascending
!
!
interface FastEthernet0
no ip address
!
interface range GigabitEthernet1/0/1 - 22
switchport access vlan 20
switchport mode access
switchport port-security maximum 4
switchport port-security violation restrict
switchport port-security aging time 2
switchport port-security
storm-control broadcast level 10.00
storm-control multicast level 10.00
storm-control action shutdown
spanning-tree portfast
spanning-tree bpduguard enable
!
interface GigabitEthernet1/0/23
switchport mode trunk
!
!
interface Vlan1
no ip address
!
interface Vlan10
ip address 10.10.50.2 255.255.255.0
no shut
!
ip default-gateway 10.10.50.1
no ip http server
ip http authentication local
no ip http secure-server
!
ip ssh time-out 60
ip ssh port 5222 rotary 1
ip ssh version 2
ip scp server enable
!
logging trap notifications
!
!
!
line con 0
exec-timeout 5 0
line vty 0 4
exec-timeout 5 0
login local
rotary 1
transport input all
line vty 5 15
login
!
ntp server 172.16.50.2 prefer
ntp server 172.16.50.4
end

[Deepak Kumar]

Hi, Please check following things.

1. VLAN configuration on (vlan 20).

2. Trunk port (uplink). Any VLAN tagging issue between the remote device and this device. Check the Speed also.

3. Enable or disable IP CEF command. 

Regards,

Deepak Kumar