Cisco 2950 to Juniper EX4200 problems

Nils Sandborg · ‎10-24-2011

I have a lot of problems with the connection between our Cisco 2950 and Juniper EX4200.

We got two different types of connection, two swtiches with LAG (LACP) and three switches with standard Trunk (STP).

The Problem:

If i connect a new switch to the EX4200, both LAG-interfaces goes down with the following message in the cisco-log:

%PM-4-ERR_DISABLE: channel-misconfig error detected on Po1, putting Gi0/1 in err-disable state

: %PM-4-ERR_DISABLE: channel-misconfig error detected on Po1, putting Gi0/2 in err-disable state

This does not always happen, maybe 20-40% of the times i connect a new swtich or move a switch from a port to another.

This happens reglardless if i have the EX4500 connected or not.

Look on the attached file for setup/conf.

Eugene Khabarov · ‎10-24-2011

Look at this document:

http://www.cisco.com/en/US/tech/tk389/tk213/technologies_configuration_example09186a0080094647.shtml#errdisable

http://www.cisco.com/en/US/docs/ios/12_2sb/feature/guide/sbcelacp.html#wp1053755

A common issue during EtherChannel configuration is that the interfaces go into err-disable mode. This can be seen when Etherchannel is switched to the ON mode in one switch, and the other switch is not configured immediately. If left in this state for a minute or so, STP on the switch where EtherChannel is enabled thinks there is a loop. This causes the channeling ports to be put in err-disable state. See this example for more information on how to determine if your EtherChannel interfaces are in the err-disable state:

%SPANTREE-2-CHNL_MISCFG: Detected loop due to etherchannel misconfiguration of Gi0/9

%PM-4-ERR_DISABLE: channel-misconfig error detected on Po10, putting Gi0/9 in err-disable state

%PM-4-ERR_DISABLE: channel-misconfig error detected on Po10, putting Gi0/10 in err-disable state

Please show us "sh lacp internal" and "debug lacp" befor port becoms errdisabled.

Also try to exchange roles. Let juniper became active and cisco became passive.

Than on juniper you can control your timers with:

'set interfaces ae1 aggregated-ether-options lacp periodic fast'

As I know on 2950 you can't do same things.

---

HTH. Please rate this post if it was helpful. If this solves your problem, please mark this post as "Correct Answer."

Eugene Khabarov · ‎10-26-2011

Nils, was it helpful?

Nils Sandborg · ‎10-26-2011

Hi and thank you for your reply!

I've collected some logs from debug.

Here is the output:

.Oct 25 13:59:13: LACP: lacp_insert_partner_cd_inhibitor: didn't change sync flag.

.Oct 25 13:59:13: LACP: lacp_send_lacpdu: (Gi0/2) About to send the 110 LACPDU

.Oct 25 13:59:13: LACP: lacp_write: LACP 124 bytes out Gi0/2

.Oct 25 13:59:14: LACP: lacp_insert_partner_cd_inhibitor: didn't change sync flag.

.Oct 25 13:59:14: LACP: lacp_send_lacpdu: (Gi0/1) About to send the 110 LACPDU

.Oct 25 13:59:14: LACP: lacp_write: LACP 124 bytes out Gi0/1

.Oct 25 13:59:14: LACP: lacp_insert_partner_cd_inhibitor: didn't change sync flag.

.Oct 25 13:59:14: LACP: lacp_send_lacpdu: (Gi0/2) About to send the 110 LACPDU

.Oct 25 13:59:14: LACP: lacp_write: LACP 124 bytes out Gi0/2

.Oct 25 13:59:14: %SPANTREE-2-LOOPGUARD_BLOCK: Loop guard blocking port Port-channel1 on VLAN0210.

.Oct 25 13:59:15: LACP: lacp_insert_partner_cd_inhibitor: didn't change sync flag.

.Oct 25 13:59:15: LACP: lacp_send_lacpdu: (Gi0/1) About to send the 110 LACPDU

.Oct 25 13:59:15: LACP: lacp_write: LACP 124 bytes out Gi0/1

.Oct 25 13:59:15: LACP: lacp_insert_partner_cd_inhibitor: didn't change sync flag.

.Oct 25 13:59:15: LACP: lacp_send_lacpdu: (Gi0/2) About to send the 110 LACPDU

.Oct 25 13:59:15: LACP: lacp_write: LACP 124 bytes out Gi0/2

.Oct 25 13:59:16: LACP: lacp_insert_partner_cd_inhibitor: didn't change sync flag.

.Oct 25 13:59:16: LACP: lacp_send_lacpdu: (Gi0/1) About to send the 110 LACPDU

.Oct 25 13:59:16: LACP: lacp_write: LACP 124 bytes out Gi0/1

.Oct 25 13:59:16: LACP: lacp_insert_partner_cd_inhibitor: didn't change sync flag.

.Oct 25 13:59:16: LACP: lacp_send_lacpdu: (Gi0/2) About to send the 110 LACPDU

.Oct 25 13:59:16: LACP: lacp_write: LACP 124 bytes out Gi0/2

.Oct 25 13:59:16: %SPANTREE-2-LOOPGUARD_UNBLOCK: Loop guard unblocking port Port-channel1 on VLAN0210.

.Oct 25 13:59:17: LACP: lacp_insert_partner_cd_inhibitor: didn't change sync flag.

.Oct 25 13:59:17: LACP: lacp_send_lacpdu: (Gi0/1) About to send the 110 LACPDU

.Oct 25 13:59:17: LACP: lacp_write: LACP 124 bytes out Gi0/1

.Oct 25 13:59:17: LACP: lacp_insert_partner_cd_inhibitor: didn't change sync flag.

.Oct 25 13:59:17: LACP: lacp_send_lacpdu: (Gi0/2) About to send the 110 LACPDU

.Oct 25 13:59:17: LACP: lacp_write: LACP 124 bytes out Gi0/2

.Oct 25 13:59:17: LACP: lacp_insert_partner_cd_inhibitor: didn't change sync flag.

.Oct 25 13:59:17: LACP: lacp_send_lacpdu: (Gi0/1) About to send the 110 LACPDU

.Oct 25 13:59:17: LACP: lacp_write: LACP 124 bytes out Gi0/1

.Oct 25 13:59:18: LACP: lacp_insert_partner_cd_inhibitor: didn't change sync flag.

.Oct 25 13:59:18: LACP: lacp_send_lacpdu: (Gi0/2) About to send the 110 LACPDU

.Oct 25 13:59:18: LACP: lacp_write: LACP 124 bytes out Gi0/2

.Oct 25 13:59:18: LACP: lacp_insert_partner_cd_inhibitor: didn't change sync flag.

.Oct 25 13:59:18: LACP: lacp_send_lacpdu: (Gi0/1) About to send the 110 LACPDU

.Oct 25 13:59:18: LACP: lacp_write: LACP 124 bytes out Gi0/1

.Oct 25 13:59:19: LACP: lacp_insert_partner_cd_inhibitor: didn't change sync flag.

.Oct 25 13:59:19: LACP: lacp_send_lacpdu: (Gi0/2) About to send the 110 LACPDU

.Oct 25 13:59:19: LACP: lacp_write: LACP 124 bytes out Gi0/2

.Oct 25 13:59:19: LACP: lacp_insert_partner_cd_inhibitor: didn't change sync flag.

.Oct 25 13:59:19: LACP: lacp_send_lacpdu: (Gi0/1) About to send the 110 LACPDU

.Oct 25 13:59:19: LACP: lacp_write: LACP 124 bytes out Gi0/1

.Oct 25 13:59:20: LACP: lacp_insert_partner_cd_inhibitor: didn't change sync flag.

.Oct 25 13:59:20: LACP: lacp_send_lacpdu: (Gi0/2) About to send the 110 LACPDU

.Oct 25 13:59:20: LACP: lacp_write: LACP 124 bytes out Gi0/2

.Oct 25 13:59:20: %SPANTREE-2-LOOPGUARD_BLOCK: Loop guard blocking port Port-channel1 on VLAN0003.

.Oct 25 13:59:20: %SPANTREE-2-LOOPGUARD_UNBLOCK: Loop guard unblocking port Port-channel1 on VLAN0003.

.Oct 25 13:59:20: LACP: lacp_insert_partner_cd_inhibitor: didn't change sync flag.

.Oct 25 13:59:20: LACP: lacp_send_lacpdu: (Gi0/1) About to send the 110 LACPDU

.Oct 25 13:59:20: LACP: lacp_write: LACP 124 bytes out Gi0/1

.Oct 25 13:59:21: LACP: lacp_insert_partner_cd_inhibitor: didn't change sync flag.

.Oct 25 13:59:21: LACP: lacp_send_lacpdu: (Gi0/2) About to send the 110 LACPDU

.Oct 25 13:59:21: LACP: lacp_write: LACP 124 bytes out Gi0/2

.Oct 25 13:59:21: LACP: lacp_insert_partner_cd_inhibitor: didn't change sync flag.

.Oct 25 13:59:21: LACP: lacp_send_lacpdu: (Gi0/1) About to send the 110 LACPDU

.Oct 25 13:59:21: LACP: lacp_write: LACP 124 bytes out Gi0/1

.Oct 25 13:59:21: %SPANTREE-2-LOOPGUARD_UNBLOCK: Loop guard unblocking port Port-channel1 on VLAN0006.

.Oct 25 13:59:21: LACP: lacp_insert_partner_cd_inhibitor: didn't change sync flag.

.Oct 25 13:59:21: LACP: lacp_send_lacpdu: (Gi0/2) About to send the 110 LACPDU

.Oct 25 13:59:21: LACP: lacp_write: LACP 124 bytes out Gi0/2

.Oct 25 13:59:22: %SPANTREE-2-LOOPGUARD_BLOCK: Loop guard blocking port Port-channel1 on VLAN0007.

.Oct 25 13:59:22: LACP: lacp_insert_partner_cd_inhibitor: didn't change sync flag.

.Oct 25 13:59:22: LACP: lacp_send_lacpdu: (Gi0/1) About to send the 110 LACPDU

.Oct 25 13:59:22: LACP: lacp_write: LACP 124 bytes out Gi0/1

.Oct 25 13:59:22: LACP: lacp_insert_partner_cd_inhibitor: didn't change sync flag.

.Oct 25 13:59:22: LACP: lacp_send_lacpdu: (Gi0/2) About to send the 110 LACPDU

.Oct 25 13:59:22: LACP: lacp_write: LACP 124 bytes out Gi0/2

.Oct 25 13:59:23: LACP: lacp_insert_partner_cd_inhibitor: didn't change sync flag.

.Oct 25 13:59:23: LACP: lacp_send_lacpdu: (Gi0/1) About to send the 110 LACPDU

.Oct 25 13:59:23: LACP: lacp_write: LACP 124 bytes out Gi0/1

.Oct 25 13:59:23: LACP: lacp_insert_partner_cd_inhibitor: didn't change sync flag.

.Oct 25 13:59:23: LACP: lacp_send_lacpdu: (Gi0/2) About to send the 110 LACPDU

.Oct 25 13:59:23: LACP: lacp_write: LACP 124 bytes out Gi0/2

.Oct 25 13:59:24: LACP: lacp_insert_partner_cd_inhibitor: didn't change sync flag.

.Oct 25 13:59:24: LACP: lacp_send_lacpdu: (Gi0/1) About to send the 110 LACPDU

.Oct 25 13:59:24: LACP: lacp_write: LACP 124 bytes out Gi0/1

.Oct 25 13:59:24: LACP: lacp_insert_partner_cd_inhibitor: didn't change sync flag.

.Oct 25 13:59:24: LACP: lacp_send_lacpdu: (Gi0/2) About to send the 110 LACPDU

.Oct 25 13:59:24: LACP: lacp_write: LACP 124 bytes out Gi0/2

.Oct 25 13:59:25: LACP: lacp_insert_partner_cd_inhibitor: didn't change sync flag.

.Oct 25 13:59:25: LACP: lacp_send_lacpdu: (Gi0/1) About to send the 110 LACPDU

.Oct 25 13:59:25: LACP: lacp_write: LACP 124 bytes out Gi0/1

.Oct 25 13:59:25: LACP: lacp_insert_partner_cd_inhibitor: didn't change sync flag.

.Oct 25 13:59:25: LACP: lacp_send_lacpdu: (Gi0/2) About to send the 110 LACPDU

.Oct 25 13:59:25: LACP: lacp_write: LACP 124 bytes out Gi0/2

.Oct 25 13:59:26: LACP: lacp_insert_partner_cd_inhibitor: didn't change sync flag.

.Oct 25 13:59:26: LACP: lacp_send_lacpdu: (Gi0/1) About to send the 110 LACPDU

.Oct 25 13:59:26: LACP: lacp_write: LACP 124 bytes out Gi0/1

.Oct 25 13:59:26: LACP: lacp_insert_partner_cd_inhibitor: didn't change sync flag.

.Oct 25 13:59:26: LACP: lacp_send_lacpdu: (Gi0/2) About to send the 110 LACPDU

.Oct 25 13:59:26: LACP: lacp_write: LACP 124 bytes out Gi0/2

.Oct 25 13:59:27: LACP: lacp_insert_partner_cd_inhibitor: didn't change sync flag.

.Oct 25 13:59:27: LACP: lacp_send_lacpdu: (Gi0/1) About to send the 110 LACPDU

.Oct 25 13:59:27: LACP: lacp_write: LACP 124 bytes out Gi0/1

.Oct 25 13:59:27: LACP: lacp_insert_partner_cd_inhibitor: didn't change sync flag.

.Oct 25 13:59:27: LACP: lacp_send_lacpdu: (Gi0/2) About to send the 110 LACPDU

.Oct 25 13:59:27: LACP: lacp_write: LACP 124 bytes out Gi0/2

.Oct 25 13:59:28: LACP: lacp_insert_partner_cd_inhibitor: didn't change sync flag.

.Oct 25 13:59:28: LACP: lacp_send_lacpdu: (Gi0/1) About to send the 110 LACPDU

.Oct 25 13:59:28: LACP: lacp_write: LACP 124 bytes out Gi0/1

.Oct 25 13:59:28: LACP: lacp_insert_partner_cd_inhibitor: didn't change sync flag.

.Oct 25 13:59:28: LACP: lacp_send_lacpdu: (Gi0/2) About to send the 110 LACPDU

.Oct 25 13:59:28: LACP: lacp_write: LACP 124 bytes out Gi0/2

.Oct 25 13:59:29: LACP: lacp_insert_partner_cd_inhibitor: didn't change sync flag.

.Oct 25 13:59:29: LACP: lacp_send_lacpdu: (Gi0/1) About to send the 110 LACPDU

.Oct 25 13:59:29: LACP: lacp_write: LACP 124 bytes out Gi0/1

.Oct 25 13:59:29: LACP: lacp_insert_partner_cd_inhibitor: didn't change sync flag.

.Oct 25 13:59:29: LACP: lacp_send_lacpdu: (Gi0/2) About to send the 110 LACPDU

.Oct 25 13:59:29: LACP: lacp_write: LACP 124 bytes out Gi0/2

.Oct 25 13:59:30: LACP: lacp_insert_partner_cd_inhibitor: didn't change sync flag.

.Oct 25 13:59:30: LACP: lacp_send_lacpdu: (Gi0/1) About to send the 110 LACPDU

.Oct 25 13:59:30: LACP: lacp_write: LACP 124 bytes out Gi0/1

.Oct 25 13:59:30: LACP: lacp_insert_partner_cd_inhibitor: didn't change sync flag.

.Oct 25 13:59:30: LACP: lacp_send_lacpdu: (Gi0/2) About to send the 110 LACPDU

.Oct 25 13:59:30: LACP: lacp_write: LACP 124 bytes out Gi0/2

.Oct 25 13:59:30: LACP: lacp_insert_partner_cd_inhibitor: didn't change sync flag.

.Oct 25 13:59:30: LACP: lacp_send_lacpdu: (Gi0/1) About to send the 110 LACPDU

.Oct 25 13:59:30: LACP: lacp_write: LACP 124 bytes out Gi0/1

.Oct 25 13:59:31: LACP: lacp_insert_partner_cd_inhibitor: didn't change sync flag.

.Oct 25 13:59:31: LACP: lacp_send_lacpdu: (Gi0/2) About to send the 110 LACPDU

.Oct 25 13:59:31: LACP: lacp_write: LACP 124 bytes out Gi0/2

.Oct 25 13:59:31: LACP: lacp_insert_partner_cd_inhibitor: didn't change sync flag.

.Oct 25 13:59:31: LACP: lacp_send_lacpdu: (Gi0/1) About to send the 110 LACPDU

.Oct 25 13:59:31: LACP: lacp_write: LACP 124 bytes out Gi0/1

.Oct 25 13:59:32: %PM-4-ERR_DISABLE: channel-misconfig (STP) error detected on Gi0/1, putting Gi0/1 in err-disable state

.Oct 25 13:59:32: LACP: lacp_hw_off: Gi0/1 is going down

.Oct 25 13:59:32: LACP: if_down: Gi0/1

.Oct 25 13:59:32: LACP: lacp_hw_off: send pdu out Gi0/1

.Oct 25 13:59:32: LACP: lacp_insert_partner_cd_inhibitor: didn't change sync flag.

.Oct 25 13:59:32: LACP: lacp_send_lacp_off: (Gi0/1) About to send the 110 LACPDU

.Oct 25 13:59:32: LACP: lacp_write: LACP 124 bytes out Gi0/1

.Oct 25 13:59:32: %PM-4-ERR_DISABLE: channel-misconfig (STP) error detected on Gi0/2, putting Gi0/2 in err-disable state

.Oct 25 13:59:32: LACP: lacp_hw_off: Gi0/2 is going down

.Oct 25 13:59:32: LACP: if_down: Gi0/2

.Oct 25 13:59:32: LACP: lacp_hw_off: send pdu out Gi0/2

.Oct 25 13:59:32: LACP: lacp_insert_partner_cd_inhibitor: didn't change sync flag.

.Oct 25 13:59:32: LACP: lacp_send_lacp_off: (Gi0/2) About to send the 110 LACPDU

.Oct 25 13:59:32: LACP: lacp_write: LACP 124 bytes out Gi0/2

.Oct 25 13:59:32: %PM-4-ERR_DISABLE: channel-misconfig (STP) error detected on Po1, putting Gi0/1 in err-disable state

.Oct 25 13:59:32: %PM-4-ERR_DISABLE: channel-misconfig (STP) error detected on Po1, putting Gi0/2 in err-disable state

.Oct 25 13:59:32: %PM-4-ERR_DISABLE: channel-misconfig (STP) error detected on Po1, putting Po1 in err-disable state

.Oct 25 13:59:32: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan3, changed state to down

.Oct 25 13:59:33: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/1, changed state to down

.Oct 25 13:59:33: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet0/2, changed state to down

.Oct 25 13:59:33: %LINEPROTO-5-UPDOWN: Line protocol on Interface Port-channel1, changed state to down

.Oct 25 13:59:34: %LINK-3-UPDOWN: Interface GigabitEthernet0/1, changed state to down

.Oct 25 13:59:34: %LINK-3-UPDOWN: Interface Port-channel1, changed state to down

.Oct 25 13:59:34: %LINK-3-UPDOWN: Interface GigabitEthernet0/2, changed state to down

I also got logs when i debug spanning-tree and lacp, but thats pretty much text so i can attach it as an file if you want.

Thanks for your help!

Nils Sandborg · ‎10-26-2011

Here are the logs from debugging STP and LACP.

Eugene Khabarov · ‎10-26-2011

Did you try to exhange active and passive devices and tune timers?

What does "sh lacp internal" shows?

Can you please post here full configuration if it possible?

___

HTH. Please rate this post if it was helpful. If this solves your problem, please mark this post as "Correct Answer"

Nils Sandborg · ‎10-26-2011

I've tried both active - active, active - passive and passive - active.

Timers is untouched.

#sh lacp internal

Flags: S - Device is requesting Slow LACPDUs

F - Device is requesting Fast LACPDUs

A - Device is in Active mode P - Device is in Passive mode

Channel group 1

LACP port Admin Oper Port Port

Port Flags State Priority Key Key Number State

Gi0/1 SA bndl 32768 0x1 0x1 0x19 0x3D

Gi0/2 SA bndl 32768 0x1 0x1 0x1A 0x3D

#sh lacp neighbor

Flags: S - Device is requesting Slow LACPDUs

F - Device is requesting Fast LACPDUs

A - Device is in Active mode P - Device is in Passive mode

Channel group 1 neighbors

Partner's information:

LACP port Oper Port Port

Port Flags Priority Dev ID Age Key Number State

Gi0/1 FP 127 28c0.da42.4f00 27s 0xF 0x14 0x3E

Gi0/2 FP 127 28c0.da42.4f00 27s 0xF 0x34 0x3E

I'll attach the swicht-configuration.

Eugene Khabarov · ‎10-26-2011

I think timers is the key subject here. You need to modify your configuration as I mentioned earlier. Juniepr will became active and timers will be set to fast. Can you also paste JunOS configuration here?

Another possible cause is you have some kind of misconfiguration in JunOS.

Maybe there is another solution but I'am not sure - try to use static mode on. Since you have dire4ct physical connectivity it will not lead to any issues.

___

HTH. Please rate this post if it was helpful. If this solves your problem, please mark this post as "Correct Answer"

Nils Sandborg · ‎10-26-2011

Ok, I've tried to set the Juniper to active with the same result.

I'll attach the Juniper-configuration.

The interface ge-0/0/14, ge-1/0/14 have ae14 as logical interface.

The interface ge-0/0/16, ge-1/0/16 have ae16 as logical interface.

These two are connected to the two cisco-switches that runs LACP.

Reza Sharifi · ‎10-26-2011

So, you are conecting 2 interfaces from the same 4200 to 2 different 2950s?

Also, in your Juniper config, I only see one interface being part of each ae instead of 2 why?

ge-0/0/14 {

description ***1b;

ether-options {

802.3ad ae14;

HTH

Nils Sandborg · ‎10-26-2011

No, according the picture in the first post, two 2950 is connected to the 4200, with one lag (2 interfaces) per switch.

If you look futher down you see that ge-1/0/14 is a part of ae14 too.

So there is two physical interfaces connected to each Port-channel/LAG.

Eugene Khabarov · ‎10-31-2011

Try to use on catalysts:

no spanning-tree etherchannel guard misconfig

and chech if the topology is stable.

Also try to use static mode on.

Please let me know if it was helpful.

___

HTH. Please rate this post if it was helpful. If this solves your problem, please mark this post as "Correct Answer"

Nils Sandborg · ‎10-31-2011

No difference with static.

If I change to VSTP instead of RSTP on Juniper EX4200 the problem disappears.

So, it seems to be a PVST/RSTP compability-issue, even if Juniper says it's going to work.

But I'll try with "no spanning-tree etherchannel guard misconf" anyway!

sg2810cisco · ‎02-29-2012

For the LACP config on the juniper devices you have to change the timer interval to slow.

For example:

'set interfaces ae1 aggregated-ether-options lacp periodic slow'

Set the LACP mode on juniper to passive and on cisco to active.

That's the key ... Figure it out.

johnnylingo · ‎11-18-2013

I just hit the same issue between a 3750X stack and Dell/Force10 S4810. Both sides are configured for MST and LACP, but there was one access layer switch running Rapid-PVST. Looks like receiving the PVST BPDU triggered the LACP Channel to re-initialize, which in turn triggered EtherChannel misconfig.

Nov 17 16:23:59 PST: %SPANTREE-2-PVSTSIM_FAIL: Blocking root port Po1: Inconsitent inferior PVST BPDU received on VLAN 444, claiming root 49642:7cad.74bf.9900

Nov 17 16:24:21 PST: %SPANTREE-2-PVSTSIM_OK: PVST Simulation inconsistency cleared on port Port-channel1.

Nov 17 16:25:12 PST: %PM-4-ERR_DISABLE: channel-misconfig (STP) error detected on Te2/1/1, putting Te2/1/1 in err-disable state

Nov 17 16:25:12 PST: %PM-4-ERR_DISABLE: channel-misconfig (STP) error detected on Te1/1/1, putting Te1/1/1 in err-disable state

If I set the 3750Xs for Rapid-PVST, I can't duplicate the problem. "no spanning-tree etherchannel guard misconfig" also fixes it.