telnet query from switch to router with ROAS

[John Cheetley]

Hi Team,

I looked for this query for layer 2 but only found one for layer 3 switches so if there is already a discussion for this then please advise..Thanks in advance

1. Should a layer 2 switch be able to ping/telnet/traceroute to a router and vice versa using the ROAS model

2. Is it easier to telnet/ssh from the PC/server to switch then router or from PC directly to router or is that just a preference thing?

[John Cheetley]

Hi Richard, 

IP address 10.100.10.1 255.0.0.0 was just a muck around IP.  Forget to update this. Sorry

Was a little confused. I presume ip default-gateway is my ISP's modem. vlan 1 native and linking to router side..anyway

Both router and switch updated.. what a learning curve.config attached..

Please let me know your thoughts...

[Richard Burts · Accepted solution]

Thanks for the update. The configst still have some issues.

1) on the router you added a subinterface under FA0/0. I am not sure what you intend to do with it.

2) there is still no subinterface for vlan 1 on the router, and so no entry for subnet 192.168.10.0

3) the subinterface on the router for vlan 3 still is configured so that it expects frames to be tagged. but the switch configures vlan 3 as the native vlan on the trunk and so will send frames with no tag.

4) the subinterface on the router for vlan 3 now has its network as 192.168.20.0. This is different from the last config that you posted. I am not sure why you changed it. And it produces a conflict with the switch config which puts 192.168.20.0 on vlan 4

5) the router now has only one static default route, which is probably better. But the new static default route

ip route 0.0.0.0 0.0.0.0 192.168.10.2

has a next hop in a subnet that is not known to the router. (where is subnet 192.168.10.0) so if you do show ip route on the router I expect you will find that there is not a gateway of last resort in the routing table

6) the switch has its default gateway as 192.168.10.1. There is only one active SVI on the switch (interfaces vlan 3 and 4 are shutdown) and its address is 192.168.10.2 and this vlan does not have a subinterface on the router. So I don't know  how the switch will get to its gateway.

HTH

Rick

[John Cheetley]

Thanks Richard,

After all the reading0, I conclude that the missing IP address for the router would be the default gteway of the cisco router or the ISP router that connects to the internet. And I presume this would be a next hop interface address situation. Being 192.168.20.1

[Richard Burts]

The router config had this static default route

ip route 0.0.0.0 0.0.0.0 192.168.10.2

which looks like it would be pointing to the switch vlan interface. That is not what you want to do. I believe that what you want is for the layer 2 switch to have its ip default-gateway point at the router interface in its management vlan (which appears to be vlan 1). On the router you want a default route to point to the ISP device as its next hop.

HTH

Rick