Do you need to have vlan 5 get access to this building but not the other way around? You can configure an acl on the svi for vlan 5 on your core switch. If you don't need them to have access to vlan 5 at all, don't create the vlan on the switch and don't allow the vlan over the trunk to that switch.
What type of switch is in building 5? L2 or L3? Is there a direct connect from this new building to Building 5 (I'm assuming not.) It may help to have a diagram of what your layout is to so we can see the path the data would take......
[toc:faq]The ProblemOn traditional switches whenever we have a trunk
interface we use the VLAN tag to demultiplex the VLANs. The switch needs
to determine which MAC Address table to look in for a forwarding
decision. To do this we require the switch to do...
[toc:faq]Introduction:Netdr is a tool available on a RSP720, Sup720 or
Sup32 that allows one to capture packets on the RP or SP inband. The
netdr command can be used to capture both Tx and Rx packets in the
software switching path. This is not a substitut...
IntroductionOSPF, being a link-state protocol, allows for every router
in the network to know of every link and OSPF speaker in the entire
network. From this picture each router independently runs the Shortest
Path First (SPF) algorithm to determine the b...