Connecting 2 4500X-16 via fiber.

[Kevin Hamilton]

I have a 10k fiber run I want to verify so I thought I would put a 4500X at each end.  The fiber is connected to T1/1 on each 4500 and ports show up/up.  I put a PC on T1/2 at each end and tried to ping between them but it doesn't work.  I have not added any VLANs and show vlan brief shows all ports in VLAN1.  

Do I need to create VLANs and/or Trunk ports to make this work?

Thanks, Kevin

[marce1000]

 - Check ip addressing schemes on both PC's (same subnet) and make sure the vlan subnet matches (if configured) 

 M.

[Kevin Hamilton]

The PCs are in the same subnet and all ports are in VLAN 1.

PC A IP: 10.100.0.5 Mask: 255.255.0.0 GW:10.100.0.1

PC B IP: 10.100.0.10 Mask: 255.255.0.0 GW:10.100.0.1

Pinging from 10.100.0.5 to .10 or from .10 to .5 gets no response.

Thanks, Kevin

[marce1000]

 -  Does the gateway exist  and or does it respond to ping ? Also post running-config of ports where PC's are connected.

 M.

[Kevin Hamilton]

Hello Marce and thank you for your help.

I'm getting back to basics, so right now I have one 4500X with a PC on T1/3 and a PC on T1/5.  No router, no gateway, and no connection to any other switches.  Both PCs are in the 10.100.0.0/16 subnet.  I cannot ping from one PC (10.100.0.5) to the other (10.100.0.10).  Both PCs are linked and ports are up/up.  I put both PCs on a basic trendnet enterprise SOHO switch and I can ping between them as expected. 

Running config attached as a txt file.

[Marvin Rhoads]

Make sure each of the interfaces you are connected to is an access port (and set spanning-tree portfast just to make it immediately forward traffic vs. having to wait ~30 seconds).

conf t
int te1/3
sw mode access
spanning-tree portfast
int te1/5
sw mode access
spanning-tree portfast
end
wr mem

[Kevin Hamilton]

Thank you Marvin.  I modified config as suggested and I still cannot ping between two hosts.  I gave up on the 4500X and put in a spare 3750X and now it works.  So I went back to my original goal of connecting two switches together with fiber and it all works end to end with 3750s.

[marce1000]

 - Configure the ports where the PC's are connected with : switchport mode host

 M.

[Kevin Hamilton]

Thank you Marce.  'switchport mode host' is not available on the 4500X, so I gave up on it and put in a spare 3750X and now it works.  So I went back to my original goal of connecting two switches together with fiber and it all works end to end with 3750s.

[MHM Cisco World]

why you mention fiber ?
yes sometimes fiber have connectivity issue.

[Kevin Hamilton · Accepted solution]

My original goal was to test a 10k fiber run by connecting a switch at each end with a PC attached, then pinging or transferring files between PCs.  I could not make it work with 4500X switches so I tried it with a couple spare 3750Xs and it worked as expected.  Thanks to all that had suggestions.  Kevin