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tolinromeFlag for United States of America asked on

ping layer 3 switch and hosts

I have a lab with different networks and on one network I have a layer 2 and layer 3 switch, the layer 3 switch is connected to a router. I have a few different vlans on this network. All vlans can communicate with each other and the switches and router.

I can ping externally to another client on another network form the layer 3 switch with no problem. However, I cannot ping from the layer 2 switch or computers on the vlans on the same network to these external hosts. What is it that is preventing replies when I ping externally?
There are no acl's on the routers.
Switches / HubsRoutersNetworking

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8/22/2022 - Mon
Trenton Knew

is the switchport access mode to the router a trunk or is it only assigned to one vlan?  If the layer 3 switch is not routing inter-vlan traffic, the port connected to the router will have to be trunked, and the router itself will have to support inter-vlan routing and trunking.
Trenton Knew

are there multiple vlans on the layer 2 switch also?  is the switchport access mode between the port on the L2 switch and L3 switch trunked as well?

Best gues is a missing route back on router to vlan with problem.

But please provide details: IP, dgw. and net-mask for a client with problem.
For L3-switch: IP & net-mask for involved vlans and dgw.
for router:IP & net-mask for involved vlans and IP routes back to client-network.
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L3 switch is the DG for the vlans, I set up int vlans XX on it as below:
10..120.1 and etc

L2 switch has these vlans as well (obviously not int vlans, just vlans). host computers are connect to the L2 switch only.
On the L3 switch there is the "ip routing" command for internal vlan routing and the statement "ip route" which is the internal interface of the router. Vlan 60 is the vlan that connects the L3 switch to the router. It is only 2 interfaces, the L3 switch and router.

So you have a number of networks with net-mask
your dgw of L3-sw is
For packets to come back from your router there must exist 'routes back' like
IP ROUTE  netmask  gw
The syntax probably is not exact , but to reach an address in the range a packet arriving at router has no directly connected network to turn to and should not go via dgw (to internet) but via L3-switch.
Instead of a lot of routes like that you probably can bundle them with a broader net-mask than

I already had "ip route" and it wasn't working and now I added:
R1(config)#ip route
R1(config)#ip route
R1(config)#ip route
R1(config)#ip route

and it still doesn't work.
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Could a there be a firewall-rule on the destination PC?
Did you try disable firewall or pinging printer instead of PC?
Did you try traceroute/tracert both ways?

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