Physical connection to a 3550 L3 ROUTED port ??

[shahedvoicerite]

Hi,

Say I have a 3550, with a ROUTED port, with an IP address of 10.1.1.1

        interface fa 0/10

          no switchport

          ip address 10.1.1.1 255.255.255.0

        I also have a SVI's and VLAN (172) with 5 ports on it (fa 0/27 - 31)

         vlan 172

           name vlan for servers

         Interface vlan 172

                no switchport

                ip address 172.16.15.1 255.255.255.0

         I have a server attached to one of these 5 ports, in access mode with IP 172.16.15.100

           interface fa 0/27

                 switchport access vlan 172

                  description Connect to server with ip 172.16.15.100

Now, I have a PC on a switch in vlan 10 with IP 10.1.1.100 with gw as 10.1.1.1 . Its connected to a 2950

The 2950 (fa 0/1) is connected to the 3550 (fa 0/10 . .routed port ....see config above).

             (Main question relates to how the 2950 switchport should be connected to the routed port).

So we have

       [ PC_A ] <----- access vlan10 ------> [ Sw 2950] < fa0/1------ Cat 5------ fa0/10---> [ 3550]  <- fa0/27-------->Server_B

     PC_A :-

              IP address :  10.1.1.100/24

              Default Gw :  10.1.1.1

              VLAN 10 on SW_2950

     Server_B :-

              IP address : 172.16.15.100

              g/w of 172.16.15.1

              VLAN 172 (access mode) on port fa0/27 of 3550.

So now, the QUESTION is :- 

          Assuming that  routing on the 3550 is enabled.

          To get PC_A to talk to Server_B, what does the config on port fa 0/1 on the 2950 have to be ???

          A. Can it just be a Access mode on vlan 10 ? (My best guess)

          B. Can it be a Trunk ?

                       not sure, since 3550 does not allow sub interfaces on routed ports            

          C. Other  ?

Thanks

[Jon Marshall · Accepted solution]

Your best guess is correct, fa0/1 on the 2950 should be allocated to vlan 10.

Incidentally, normally with a L3 switch you would not use a routed port, you would simply allocate fa0/10 on the 3550 into vlan 10 and then create a L3 SVI for vlan 10 on the 3550 eg.

int vlan 10

ip address 10.1.1.1 255.255.255.0

but your way will still work.

Jon