Cisco Catalyst 4500 Series, Руководство по настройке программного обеспечения, Страница: 2011 / 2086

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Catalyst 4500 Series Switch, Cisco IOS Software Configuration Guide - Cisco IOS XE 3.9.xE and IOS 15.2(5)Ex
Chapter 83 Configuring Easy Virtual Network
About Easy Virtual Network
Figure 83-5 Packet Flow in a Virtual Network
The packet flow from Laptop 1 to Server 1 in VRF red occurs as follows:
1.
Laptop 1 send an untagged packet to Server 1.
2.
Device A receives the packet over an edge interface, which is associated with VRF red.
a.
Device A does route lookup in VRF red and sees that the next hop is Device B through a trunk
interface.
b.
Device A encapsulates the packet with VRF red’s tag (101) and sends it over the trunk interface.
3.
Device B receives the packet over a trunk interface. Seeing virtual network tag 101, Device B
identifies that the packet belongs to VRF red.
a.
Device B does route lookup in VRF red and sees that the next hop is Device C through a trunk
interface.
b.
Device B encapsulates the packet with VRF red’s tag (101) and sends it over the trunk interface.
4.
Device C receives the packet over a trunk interface. Using virtual network tag 101, Device C
identifies that the packet belongs to VRF red.
a.
Device C does route lookup in VRF red and sees that the next hop is Device D through a trunk
interface.
b.
Device C encapsulates the packet with VRF red’s tag (101) and sends it over the trunk interface.
5.
Device D receives the packet over a trunk interface. Using virtual network tag 101, Device D
identifies that the packet belongs to VRF red.
a.
Device D does route lookup in VRF red and sees that the next hop is through an edge interface.
b.
Device D sends the untagged packet over the edge interface to Server 1.
6.
Server 1 receives the untagged packet originated from Laptop 1.
Edge interf a ce Edge interf a ce Tr u nk interf a ce s m a ke u p the VRF core
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8
97
E a ch as teri s k indic a te s VRF definition
E a ch d as hed line indic a te s edge interf a ce
P a r a llel s olid line s gro u p indic a te s tr u nk interf a ce
Device A Device B Device C
Device E Device F Device G
Device D
S erver 1
L a ptop 1
L a ptop 2
S erver 1
101 101
102 102
102
102
101