2 Replies Latest reply: Oct 13, 2018 6:16 AM by Steve RSS

    unable to route across devices in packet tracer


      Hello All,


      Please help me out. I'm simulating these configs before working on the actual devices. Thanks in advance.


      Attached is the Cisco Packet Tracer configuration file you can upload to your Cisco Packet Tracer to see all my configs. I believe my router configs is the problem, but can't seem to isolate and pin point where to begin, fix, change, etc.


      I've been having a problem with my configuration trying to route across the network. The layer 3 switch has IP Routing enabled and the PCs on the switch can all communicate on the local switch by interval routing.


      However, I can NOT seem to ping the devices attached to the hwic-4esw (ethernet card) installed on my 1941 router from the devices attached to the switch. I need to basically have communication across my network.


      I've attempted the router on a stick method and have redone all the configs to use routed ports instead, I hope this was the right choice to give added flexibility.


      Please also let me know if additional information is needed.


        • 1. Re: unable to route across devices in packet tracer



          You must have in count the concept of vlans.


          A vlan creates a broadcast domain, then, see your topology and ip configuration


          Router0 receive a packet with a source and destination, then, Router0 thinks the destination ip address is in the same broadcast domain (vlan 100) that is directly connected, obviosly, it will not send the packet to the Multilayer Switch.



          Althougth you can the same ID vlan 100 in the router and the Multilayer Switch, they aren't in the same broadcast domain. For that reeason, you must configure, for example:



          interface vlan 100:


          Multilayer Switch

          interface vlan 100:


          Best regards!

          • 2. Re: unable to route across devices in packet tracer

            That was it! Cross communication works nicely thanks to you.


            I later got into a hiccup with my OSPF adverstisement and realized it so I was able to learn how to fix it too.  :-)


            Thank you for your kind help and time.