JUNOS Link Aggregation Configuration

Objective: Creating aggregated interface between two switches (Cisco calls it Ether-channel)

First step
Define how many aggregation you want to have in JUNOS (for resource allocation)

command is: set chassis aggregated-devices ethernet device-count x

root# set chassis aggregated-devices ethernet device-count ?
Possible completions:
Number of aggregated Ethernet devices (1..32)
[edit]
root# set chassis aggregated-devices ethernet device-count 1
[edit]
root# commit
commit complete
[edit]
root#


Second step

Delete simple L2 switching for spanning tree to disable on each particular aggregation ethernet.

root# delete interfaces ge0/0/1 unit 0
[edit]
root# delete interfaces ge0/0/2 unit 0

Third Step

root# set interfaces ge0/0/1 ether-options 802.3ad ae0
[edit]
root# set interfaces ge0/0/2 ether-options 802.3ad ae0

• ae0 is (aggregated ethernet 0) we simply linked ge0/0/1 and 2 to ae0
• to see the spanning tree information exit from [edit] or use "run" command as a prefix to your show command:

root# exit
Exiting configuration mode

root> show spanning-tree interface
Spanning tree interface parameters for instance 0
Interface Port ID Designated Designated Port State Role
port ID bridge ID Cost
ge-0/0/0.0 128:513 128:513 32768.001f1231b840 20000 BLK DIS
ge-0/0/3.0 128:516 128:516 32768.001f1231b840 20000 BLK DIS

As we can see ge0/0/1 and 2 are not there, even ae0 is not participating in spanning tree.


Fourth Step

root# set interfaces ae0 unit 0 family ethernet-switching
[edit]
root# commit
commit complete
root# exit
Exiting configuration mode

root> show spanning-tree interface

Spanning tree interface parameters for instance 0
Interface Port ID Designated Designated Port State Role
port ID bridge ID Cost
ae0.0 128:1 128:514 32768.001f1231b780 10000 FWD ROOT
ge-0/0/0.0 128:513 128:513 32768.001f1231b840 20000 BLK DIS
ge-0/0/3.0 128:516 128:516 32768.001f1231b840 20000 BLK DIS

root> show interfaces terse

Interface Admin Link Proto Local Remote
ge-0/0/0 up down
ge-0/0/0.0 up down eth-switch
ge-0/0/1 up up
ge-0/0/1.0 up up aenet –> ae0.0
ge-0/0/2 up up
ge-0/0/2.0 up up aenet –> ae0.0
ge-0/0/3 up down
ge-0/0/3.0 up down eth-switch

root> show interfaces ae0

Physical interface: ae0, Enabled, Physical link is Up
Interface index: 155, SNMP ifIndex: 143
Link-level type: Ethernet, MTU: 1514, Speed: 2000mbps, …

root> show configuration
## Last commit: 2008-07-27 14:21:15 UTC by root
version 9.0R2.10;
chassis {
aggregated-devices {
ethernet {
device-count 1;
}
}
}
interfaces {
ge-0/0/0 {
unit 0 {
family ethernet-switching;
}
}
ge-0/0/1 {
ether-options {
802.3ad ae0;
}
}
ge-0/0/2 {
ether-options {
802.3ad ae0;
}
}
ae0 {
unit 0 {
family ethernet-switching;
}
}
vme {
unit 0 {
family inet {
address 192.168.1.253/24;
}
}
}
}
root> show ethernet-switching interfaces
Interface State VLAN members Blocking
ae0.0 up default unblocked
ge-0/0/0.0 down default blocked – blocked by STP/RTG
ge-0/0/3.0 down default blocked – blocked by STP/RTG

to enable LACP for link aggregation [passive/active]:

ae0 {
aggregated-ether-options {
lacp {
passive;
}
}


Fifth Step
to enable trunk:

root# set interfaces ae0 unit 0 family ethernet-switching port-mode trunk

Overview configuration (with multiple VLANs)

chassis {
aggregated-devices {
ethernet {
device-count 1;
}
}
}
interfaces {
ge-0/0/0 {
unit 0 {
family ethernet-switching;
}
}
ge-0/0/1 {
ether-options {
802.3ad ae0;
}
}
ge-0/0/2 {
ether-options {
802.3ad ae0;
}
}
ae0 {
aggregated-ether-options {
lacp {
passive;
}
}
unit 0 {
family ethernet-switching {
port-mode trunk;
}
}
}
vlan {
unit 10 {
family inet {
address 192.168.10.1/24;
}
}
unit 11 {
family inet {
address 192.168.11.1/24;
}
}
}
vme {
unit 0 {
family inet {
address 192.168.1.253/24;
}
}
}
}
protocols {
lldp {
interface all;
}
rstp;
}
vlans {
PC1 {
vlan-id 10;
interface {
ge-0/0/10.0;
}
l3-interface vlan.10;
}
PC2 {
vlan-id 11;
interface {
ge-0/0/11.0;
}
l3-interface vlan.11;
}
PC3 {
vlan-id 30;
interface {
ge-0/0/13.0;
}
}
}
virtual-chassis {
member 0 {
mastership-priority 255;
}
}
poe {
interface all;
}
root>


Note the output of show commands:

root# show vlans
PC1 {
vlan-id 10;
interface {
ge-0/0/10.0;
}
l3-interface vlan.10;
}
PC2 {
vlan-id 11;
interface {
ge-0/0/11.0;
}
l3-interface vlan.11;
}
PC3 {
vlan-id 30;
interface {
ge-0/0/13.0;
}
l3-interface vlan.30;
}

root# run show vlans
Name Tag Interfaces
PC1 10
ge-0/0/10.0
PC2 11
ge-0/0/11.0*
PC3 30
ge-0/0/13.0
default
ge-0/0/0.0, ge-0/0/3.0…
mgmt
me0.0
[edit]