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If you want to completely isolate a VLAN do not create an SVI. If there is no router within the VLAN traffic cannot end up in another network segment.<br />
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If you just need to deny access to certain network ranges use ACLs<br />
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<pre><code id="code-20-41079045-1">//Define an extended access-list with name ACL_VLAN100
Router(config)#ip access-list extended ACL_VLAN100
//Permit Traffic from 192.168.1.0/24 to 192.168.2.0/24
Router(config-ext-nacl)#permit ip 192.168.1.0 0.0.0.255 192.168.2.0 0.0.0.255

Router(config)#interface vlan100
//Apply ACL_VLAN100 to SVI inbound. Traffic coming from VLAN100 is being inspected
Router(config-if)#ip access-group ACL_VLAN100 in</code></pre>
<br />
Keep in mind that there is an implicit deny any any hidden at the end of the ACL which means you have to explicitly allow traffic to pass.
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If you want to completely isolate a VLAN do not create an SVI. If there is no router within the VLAN traffic cannot end up in another network segment.

If you just need to deny access to certain network ranges use ACLs



//Define an extended access-list with name ACL_VLAN100
Router(config)#ip access-list extended ACL_VLAN100
//Permit Traffic from 192.168.1.0/24 to 192.168.2.0/24
Router(config-ext-nacl)#permit ip 192.168.1.0 0.0.0.255 192.168.2.0 0.0.0.255

Router(config)#interface vlan100
//Apply ACL_VLAN100 to SVI inbound. Traffic coming from VLAN100 is being inspected
Router(config-if)#ip access-group ACL_VLAN100 in


Keep in mind that there is an implicit deny any any hidden at the end of the ACL which means you have to explicitly allow traffic to pass.

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Simplest solution and works.
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I have a VLAN that I want to completely isolate. How do I make an ACL to do that?
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I have a VLAN that I want to completely isolate. How do I make an ACL to do that?

How to Creat a an ACL on a VLAN that isolates iton a 6500 Cisco Chassis

A switch is a device that filters and forwards packets of data between LAN segments. Switches operate at the data link layer or the network layer of the Open Systems Interconnection (OSI) Reference Model and therefore support any packet protocol. LANs that use switches to join segments are called switched LANs or, in the case of Ethernet networks, switched Ethernet LANs. A hub is a connection point for devices in a network. Hubs are commonly used to connect segments of a LAN. A hub contains multiple ports; when a packet arrives at one port, it is copied to the other ports so that all segments of the LAN can see all packets.

Switches / Hubs

Networking is the process of connecting computing devices, peripherals and terminals together through a system that uses wiring, cabling or radio waves that enable their users to communicate, share information and interact over distances. Often associated are issues regarding operating systems, hardware and equipment, cloud and virtual networking, protocols, architecture, storage and management.

Networking

Networking hardware includes the physical devices facilitating the use of a computer network. Typically, networking hardware includes gateways, routers, network bridges, modems, wireless access points, networking cables, line drivers, switches, hubs, and repeaters. But it also includes hybrid network devices such as multilayer switches, protocol converters, bridge routers, proxy servers, firewalls, network address translators, multiplexers, network interface controllers, wireless network interface controllers, ISDN terminal adapters and other related hardware.