Switch 3750

[mdehsan230564]

Dear Sir,

My pc are connected to a cisco 3750 switch. Switch is configured as vlan1 ip address as 10.42.4.1 255.255.255.0 primary.

And 10.42.8.1 as secondary.

PC default gateway = 10.42.4.1 and PC are getting application access through switch configure tunnel to a router.

Now the same switch 3750 i connected a another router to for internet.

since PC default gateway is to the internet router that is why i am not getting internet.

I configure my internet router LAN ip = 10.42.8.2.

What configuration in my Switch 3750 should i configure so that even PC default gateway is 10.42.4.1 not 10.42.8.1.

so that i should get internet as well as access my application.

Since my application only works if the default gateway is 10.42.4.1

Can I configure as :-

ip route 0.0.0.0 0.0.0.0 10.42.8.2 and it will solve my problem.

Thanks and best regards.

[Georg Pauwen]

Hello,

post the full running configurations (sh run) of both the router and the switch...

[Richard Burts]

A diagram showing the topology would be helpful. I am not clear about 

10.42.4.1 255.255.255.0 primary.

10.42.8.1 as secondary.

can you clarify about this?

Is ip routing enabled on this 3750? If so then please post the output of show ip route. Is vlan 1 the only vlan or are there other vlans?

[Giuseppe Larosa]

Hello @mdehsan230564 ,

I think you need to have ip routing enabled to perform inter VLAN routing even if in this case the routing is between primary and secondary address.

You need on C3750:

conf t

ip routing

ip route 0.0.0.0 0.0.0.0 10.42.8.2

Please note that the internet router may need the following:

on internet router :

a static route for subnet

ip route 10.42.4.0 255.255.255.0 10.42.8.1

and NAT configuration needs to be updated to include the 10.42.4.0/24 subnet

access-list 111 remark NAT

access-list 111 deny ip 10.42.4.0 0.0.0.255 10.42.8.0 0.0.0.255

access-lis 111 deny ip 10.42.8.0 0.0.0.255 10.42.4.0 0.0.0.255

access-list 111 permit ip 10.42.8.0 0.0.0.255 any

access-list 111 permit ip 10.42.4.0 0.0.0.255 any

ip nat source inside list 111 interface <WAN> overload

Hope to help

Giuseppe