Ethernet Switching
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Ethernet Switching

EX4300 LACP with SRX requires VSTP Edge configuration. Why.

[ Edited ]
‎09-26-2016 04:41 AM

I have a working setup with SRX and EX4200, and SRX and Cisco C3750 with LACP.

Now im moving from C3750 to EX4300.

The "show lacp interface" shows a up and running LACP bundle. But no traffic is forwarded.

The network has VSTP configured. But for this interfaces I have not defined any STP configuration.

This results in an interfaces that is not forwarding traffic.

 

The only way I manage to forward traffic via the ae-interface to the SRX is to configure "set protocols vstp interface ae3 edge".

The port is a trunk port with a few VLAN on it.

JunOS version 14.1X53-D35.3.

Why is this required?

 

//Rob

5 REPLIES 5
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Ethernet Switching

Re: EX4300 LACP with SRX requires VSTP Edge configuration. Why.

‎09-26-2016 04:50 AM

Hi, 

 

Edge port makes the port to transition to RSTP forwarding state immediately.

Do you know the STP state of the port before configuring edge:

show spanning-tree interface ae3
show ethernet-switching interfaces ae3

Cheers,

Ashvin

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Ethernet Switching

Re: EX4300 LACP with SRX requires VSTP Edge configuration. Why.

‎09-26-2016 07:21 AM

Hi,

 

I have looked over these things without any findings that points me in the right direction.

show spanning-tree interface ae3 doesnt give me any output as long as I dont have it added under "protocols vstp ae3", as expected.

The show ethernet-switching interface ae3 shows all added VLANs as in FORWARDING.

host# run show ethernet-switching interface ae3
Routing Instance Name : default-switch
Logical Interface flags (DL - disable learning, AD - packet action drop,
LH - MAC limit hit, DN - interface down,
SCTL - shutdown by Storm-control,
MMAS - Mac-move action shutdown, AS - Autostate-exclude enabled)

Logical Vlan TAG MAC STP Logical Tagging
interface members limit state interface flags
ae3.0 65535 tagged
xxm 2 65535 Forwarding tagged
xxz 3 65535 Forwarding tagged
xxx 4 65535 Forwarding tagged
xxy 5 65535 Forwarding tagged

 

When I double checked this now, I experience the even more wierd thing, ping is forwarded to the SRX (it respond to ping) but I cannot reach it via SSH.

I have been trying to pinpoint this for days. LACP looks fine, but forwarding is sometimes working and sometimes not. When doing tests this morning, the "edge" command made it work. Without, it didnt work.

When testing now again, it works with and without.

 

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Ethernet Switching

Re: EX4300 LACP with SRX requires VSTP Edge configuration. Why.

‎09-26-2016 07:55 AM

Hi, 

 

That sounds weird, although it seems to have been reported likewise here:

http://forums.juniper.net/t5/SRX-Services-Gateway/Unable-to-ping-default-gw-from-SRX240-cluster-Node...

 

Cheers,

Ashvin

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Ethernet Switching

Re: EX4300 LACP with SRX requires VSTP Edge configuration. Why.

‎10-03-2016 12:47 AM

I can report the following findings / issue.

 

This is confirmed between EX4300 and SRX240.

Configure both devices with periodic slow (as per recommendation by Juniper KB).

EX4300 as active LACP, and SRX as passive LACP.

 

Create the ae interface and assign the interfaces.

set interfaces ge-0/0/15 ether-options 802.3ad ae8

set interfaces ge-1/0/15 ether-options 802.3ad ae8

set interfaces ae8 aggregated-ether-options lacp active
set interfaces ae8 aggregated-ether-options lacp periodic slow
set interfaces ae8 unit 0 family ethernet-switching interface-mode trunk
set interfaces ae8 unit 0 family ethernet-switching vlan members VLAN2

 

If you commit this, and connect the SRX (only 1 cable in this output, but the behavior is the same. The LACP will show:

Aggregated interface: ae8
LACP state: Role Exp Def Dist Col Syn Aggr Timeout Activity
ge-0/0/15 Actor No No Yes Yes Yes Yes Slow Active
ge-0/0/15 Partner No No Yes Yes Yes Yes Slow Passive
ge-1/0/15 Actor No Yes No No No Yes Slow Active
ge-1/0/15 Partner No Yes No No No Yes Fast Passive
LACP protocol: Receive State Transmit State Mux State
ge-0/0/15 Current Slow periodic Collecting distributing
ge-1/0/15 Port disabled No periodic Detached

Looks fine.

But no traffic will be processed. No MAC will be mapped to the port (show ethernet-switching table).

 

It will work if you add:

set protocols vstp interface ae8 edge

 

This issue is easy to test again, but it requires you to delete the interfaces and add them again. Thats easy with JunOS.

delete protocols vstp interface ae8 edge (if you have added this to verify)

delete interface ge-0/0/15

set disable interface ge-0/0/15

delete interface ge-1/0/15

set disable interface ge-1/0/15

delete interface ae8

commit

rollback 1

commit

 

same issue again.

 

Waiting for some kind of info from JTAC but they aint working as fast as I was hoping. They have trace logs etc.

Anyone has any idea why edge is needed (and no, STP is not an issue in this case! everything looks fine).

 

//Rob

 

 

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Ethernet Switching
Solution
Accepted by topic author R_J
‎10-25-2016 12:40 AM

Re: EX4300 LACP with SRX requires VSTP Edge configuration. Why.

‎10-25-2016 12:39 AM

The solution was provided by JTAC.

This is a known issue that is _maybe_ solved in 15.x

https://prsearch.juniper.net/InfoCenter/index?page=prcontent&id=PR860226

 

Solution: Add all interfaces under stp. for example set protocols vstp interfaces <interface-name>.

Otherwise you might get random issues that the interface isnt learning MAC = no traffic is forwarded.

 

//Rob

 

 

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