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Routing Help

Hello guys,


I need some help with this set up. I'm trying to browse the internet from the client-PC and server.


Here is my config. Please see the pic for the physical layout.


I have a Layer 3 switch with multiple VLANS.


VLAN 70:

  ip address:

  Ports 5 and 6 are in VLAN 70 and I have two machines ( Client-PC and server)connected to it.

IP addressing is handled by DHCP running on the switch for this VLAN.


VLAN 20:

ip address:

   Port 10 is in VLAN 20  


I connected a cable from my ISP router to port 10 on the Layer3 switch.



Set a static ---> ip route



I can ping and from the Layer3 switch. But from my client-pc and server I can only ping

I cannot ping or from VLAN 70.


What did I miss here?



Re: Routing Help

Looks like your ISP router does not have route for the subnet
VIP Advisor

Re: Routing Help

Hi there,

Your router does not know how to reach the other VLANs on the switch. It will have a ‘connected’ route for /24 but probably nothing else for your internal network.


If it does have routes for your other internal subnets, then the next possible cause is NAT on the router. It may not be configured to allow subnets other than /24. If it is a low end router then typically they are hard-coded to only translate a single ‘Inside’ subnet. If this is the case you will need to NAT your internal subnets before they reach the router.




VIP Advisor

Re: Routing Help

First quick question, do you have ip routing enabled ? and doing some NAT for Vlan 70 IP ?

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VIP Mentor

Re: Routing Help


Only high end switches or routers support/perform NAT, so unless you have another router you can attached between the ISP modem and your switch or you if you can amend the ISP modem to nat also your vlan 70 subnet then I suggest the most simplistic solution will be to pull client /server in same vlan as ISP modem and use the switch as a host switch ( no ip routing or static routes) all running in the one vlan.


Alternatively if your server has two network cards and its possible regards the OS -  you could use this as a router and have one interface in the same subnet as the isp and the other nic in vlan 70 attached to your switch and have that perform NAT.


kind regards

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