Download Chapter Review Questions

Note that in this case, there is no native VLAN defined on the trunk interface. This is
the JUNOS default, and is fine for our purposes; it’s one less VLAN to have to later
remove (i.e., prune in IOS-speak) from the trunks, after all. The CLI supports the notion
of the native VLAN, as well as a wildcard match-all function, via the native and all
keywords. A set unit 0 family ethernet-switching vlan members all statement
quickly adds all defined VLANs to a trunk interface, which saves a significant degree
of work when dealing with large numbers of VLANs.
This example shows the configuration of a single logical interface (ifl) that is assigned
unit number 0. Note that in the 9.2 release used for this book, EX switches do not
support the notion of flexible Ethernet encapsulation. The result is the mandate that
any interface configured to support the ethernet-switching family must be assigned a
single unit that is assigned number 0. This limitation is demonstrated at Rum:
[edit interfaces ge-0/0/0]
lab@Rum# show
unit 0 {
family ethernet-switching {
port-mode trunk;
}
}
unit 1 {
family inet {
address 200.0.0.1/24;
}
}
[edit interfaces ge-0/0/0]
lab@Rum# commit check
[edit interfaces ge-0/0/0]
'unit 1'
Only unit 0 is valid for this encapsulation
error: configuration check-out failed
To better illustrate this point, the following example is taken from a significantly more
expensive MX platform that does offer support for flexible Ethernet services:
{master}[edit interfaces ge-5/0/3]
user@mx960# run show chassis hardware | match mx
Chassis
JN10868FCAFA
. . .
{master}[edit interfaces ge-5/0/3]
regress@auror# show
vlan-tagging;
encapsulation flexible-ethernet-services;
unit 0 {
encapsulation vlan-bridge;
vlan-id-range 3-4094;
family bridge;
}
unit 1 {
vlan-id 2;
296 | Chapter 5: Virtual LANs and Trunking
MX960