Switching

hI Guys

I have a 8 port VC across multple racks and Im trying to configure an LACP LAG on 2 switches in my VC (FPC0 & FPC1)  and on the other side its a Cisco 2950.

 

 

Although the LAG is up - on the cisco i keep seeing the 2 interfaces dropping/ flapping every 2 mins or so for about 3 secs.

 

 please see my config below:

 

*********************JUNIPER CONFIG ******************************************
show interfaces ae7
description LACP_TO_THN_MAN02_0/47_/48;
aggregated-ether-options {
link-speed 100m;
lacp {
active;
periodic slow;
}
}
unit 0 {
family ethernet-switching {
port-mode trunk;
vlan {
members [ 30 88 ];
}
native-vlan-id 30;
}
}

 

show interfaces ge-1/0/23
description "LACP_TO_Cisco;";
ether-options {
speed {
100m;
}
802.3ad ae7;
}

show interfaces ge-0/0/23
description "LACP_TO_CISCO;";
ether-options {
speed {
100m;
}
802.3ad ae7;
}
**************** END OF JUNIPER CONFIFG ***********************************************

***************CISCO CONFIG*******************************************************

show run interface Port-channel 1
Building configuration...

Current configuration : 183 bytes
!
interface Port-channel1
description LAG_TO_CORE_FPC0&1
switchport trunk native vlan 25
switchport trunk allowed vlan 30,88
switchport mode trunk
switchport nonegotiate
end

 

sh run interface F0/47
Building configuration...

Current configuration : 236 bytes
!
interface FastEthernet0/47
description TO_FPC0_ge0/0/23
switchport trunk native vlan 25
switchport trunk allowed vlan 30,88
switchport mode trunk
switchport nonegotiate
channel-group 1 mode active
channel-protocol lacp
end

 

sh run interface F0/48
Building configuration...

Current configuration : 236 bytes
!
interface FastEthernet0/48
description TO_FPC0_ge0/0/23
switchport trunk native vlan 25
switchport trunk allowed vlan 30,88
switchport mode trunk
switchport nonegotiate
channel-group 1 mode active
channel-protocol lacp
end

**************************** END CISCO CONFIG *************************************************

 

 

 

any help would be appreciated.  Ive tried the cisco being passive and juniper being active and vice versa and also tried the periodic fast onthe juniper.  no joy.

 

thanks

 

Sol

Hi Sol.

 

Please read this document:

http://kb.juniper.net/InfoCenter/index?page=content&id=KB14501

 

And please send us info about STP state, LACP state, and enable traceoptions on Juniper side or debug commands on Cisco side.

 

Bye,

your config compat with cisco in channel-group x mode on

you must add config
set interface ae x aggregate-ether-options lacp passive or active

It sounds and looks like an auto-negotiation issue - on the juniper side, remove the ether-options speed 100m from the physical interface configuration.  The gigabit ports on the Juniper should negotiate 100 FULL just fine with a 3560.

guys 

sorry for the belated update - the problem was the native vlan  issue - on the cisco side  - you have to include vlan 1 on the trunk port s (both the LACP port and switch port) and on the Juniper side include native-vlan-id default  as below

 

 

cisco config:

 

interface Port-channel1
switchport trunk allowed vlan 1,100
switchport mode trunk
switchport nonegotiate

 

interface FastEthernet0/47
switchport trunk allowed vlan 1,100
switchport mode trunk
switchport nonegotiate
duplex full
channel-group 1 mode passive
end

 

 

 

Juniper Config

 

 

how interfaces ae7
aggregated-ether-options {
link-speed 100m;
lacp {
active;
periodic slow;
}
}
unit 0 {
family ethernet-switching {
port-mode trunk;
vlan {
members [ 100 777 ];
}
native-vlan-id default;
}

 

 

show interfaces ge-0/0/23
ether-options {
link-mode full-duplex;
speed {
100m;
}
802.3ad ae7;
}