CCNP 3 Implementing Inter-VLAN Routing
From Teknologisk videncenter
Contents
Describing Routing Between VLANs
Inter-VLAN Routing Using an External Router
Configuring Inter-VLAN Routing Using an External Router
Explaining Multilayer Switching
Frame Rewrite
Enabling Routing Between VLANs
Describing Configuration Commands for Inter-VLAN Communication on a Multilayer Switch
Describing Routed Ports on a Multilayer Switch
Deploying CEF-Based Multilayer Switching
Explaining Layer 3 Switch Processing
There is a wide range of CEF-based Cisco multilayer switches:
- Catalyst 2970
- Catalyst 3550
- Catalyst 3560
- Catalyst 3750
- Catalyst 4500
- Catalyst 4948
- Catalyst 6500
Identifying the Multilayer Switch Packet Forwarding Process
- Null adjacency: Packets destined for a null0 interface are dropped. This can be used as an effective form of access filtering.
- Glean adjacency: When a router is connected directly to several hosts, the FIB table on the router maintains a prefix for the subnet rather than for the individual host prefixes. The subnet prefix points to a glean adjacency. When packets need to be forwarded to a specific host, the adjacency database is gleaned for the specific prefix.
- Punt adjacency: Features that require special handling, or features that are not yet supported in conjunction with CEF switching paths, are forwarded to the next switching layer for handling. For example, the packet may require CPU processing. Features that are not supported are forwarded to the next-higher switching level.
- Discard adjacency: Packets are discarded.
- Drop adjacency: Packets are dropped, but the prefix is checked.
