Cannot ping gatewa

[john]

Hello All,

i have  vlans

VLAN 10 - 10.0.10.1/24

VLAN 20 - 10.0.20.1/24

default VLAN

VLAN 1 - 10.0.1.2/30 - coreswitch

Router interface

VLAN 1 - 10.0.1.1/30

ip routing is enabled and default route 0.0.0.0 0.0.0.0 10.0.1.1 is configured

VLAN 10 and 20 cannot ping 10.0.1.1 hence no internet connection. please refer to attached diagram.

Coreswitch can ping 10.0.1.1

please help advise.

Regards,

John

[Julio E. Moisa]

Hi 

If it is a L3 switch and ip routing is enabled, have you configured static routes on the router to know and reach the subnets associated to the vlan 10 and 20? Remember the ping is reciprocal (outbound - inbound). Also assuming you have a interface configured on vlan 1 facing to the router. *A good practice for security purposes is that the vlan 1 should be shutdown, you should use other vlan for the point to point with the router or use the interface as layer 3 example:*

Switch

interface g1/1/1
description POINT-TO-POINT_ROUTER
no switchport
ip add 10.0.1.2 255.255.255.252
no shutdown

Router 

ip route 10.0.10.0 255.255.255.0 10.0.1.2
ip route 10.0.20.0 255.255.255.0 10.0.1.2

In order to provide Internet access, you must create a NAT on the router.

NAT Configuration example (In this case a PAT):

interface fa0/0
description INTERNET
Ip address <Public IP> <subnet>
ip nat outside
no shut

interface fa0/1
description INTERNAL-INFRASTRUCTURE
Ip address 10.0.1.1 255.255.255.252
ip nat inside
no shut

ip access-list standard PRIVATE-NETS
permit 10.0.10.0 0.0.0.255
permit 10.0.20.0 0.0.0.255

ip nat inside source list PRIVATE-NETS interface f0/0 overload

ip route 0.0.0.0 0.0.0.0 <next hop IP to ISP>     

Hope it is useful.

🙂

[Ganesh Hariharan]

Hi John,

Are you able to ping 10.0.1.1 from 10.0.1.2 ??

and what reverse route is configured on 10.0.1.1 for local subnets VLAN 10 and 20 towards 10.0.1.2.

and Nat configuration need to be check ..

Most of the stuff is already highlighted by Julio ..

Hope it Helps..

-GI