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LAG between Juniper and Cisco Router

‎05-17-2016 06:54 PM

Hello,

 

I have configured LAG between juniper and CIsci routers.

The traffic is loadshared between the peers but the thing is when one link gets down, the interfaces are not seing each other.

 

Any clue about this issue ?

 

 

Thanks

6 REPLIES 6
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Re: LAG between Juniper and Cisco Router

‎05-18-2016 03:32 AM

Is the minimum links option configured?  This would force the AE bundle down even with a single link up.

 

Do the physiscal interfaces show the expected links and just the AE is down or all links showing down?

Steve Puluka BSEET - Juniper Ambassador
IP Architect - DQE Communications Pittsburgh, PA (Metro Ethernet & ISP)
http://puluka.com/home
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Re: LAG between Juniper and Cisco Router

‎05-18-2016 04:41 AM

Thanks Supuluka.

 

I have configured minimum links to 1 in both side.

When one link get down, the AE is still Up linke this :

 

****@GHSR02> show interfaces terse | match ae0
ge-0/2/1.0 up up aenet --> ae0.0
ge-1/1/0.0 up down aenet --> ae0.0
ae0 up up
ae0.0 up up inet 172.26.255.118/30

 

Juniper Settings:

 

set chassis aggregated-devices ethernet device-count 5

 

set interfaces ge-1/1/0 gigether-options 802.3ad ae0

set interfaces ge-0/2/1 gigether-options 802.3ad ae0

 

set interfaces ae0 aggregated-ether-options minimum-links 1
set interfaces ae0 aggregated-ether-options link-speed 1g

 

set interfaces ae0 mtu 4470
set interfaces ae0 unit 0 description Towards_MRSR02
set interfaces ae0 unit 0 family inet mtu 1522
set interfaces ae0 unit 0 family inet address 172.26.255.118/30
set interfaces ae0 unit 0 family mpls

 

 

 

But the peers are not seeing each other. I just wanted to highlight that the media in between are FO.

And that no lacp is set. Cause the peers are not seeing each other when I set lacp active in one side.

 

I am wondering whether it makes sens to configure LAG between routers since all the posts I am seeing are between Routers and Switches.

 

Please advise

 

Thanks

 

 

 

 

 

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Re: LAG between Juniper and Cisco Router

‎05-18-2016 06:19 AM

Ephs_NE,

 

Since you have configured minmum link as "1" and the AE has 2 member links in it.

When you shut down one of the member links, the condition for AE to be up is still TRUE ( there is one more member link that is up ) and hence AE stays up.

 

Configure minimum link as "2" and down of one the member link. You AE will be down then

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Re: LAG between Juniper and Cisco Router

‎05-18-2016 07:15 AM

Thanks SudarShan,

 

I agree with you but the thing is although AE remains UP, the pings are not happening. It's not working.

It's like we are not able to see the remote peer.

 

 

Any idea ?

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Re: LAG between Juniper and Cisco Router

‎05-18-2016 06:05 PM

Check the steps listed at #13 in KB19798 to determine why traffic is not passing on the LAG.

 

http://kb.juniper.net/InfoCenter/index?page=content&id=KB19798

Steve Puluka BSEET - Juniper Ambassador
IP Architect - DQE Communications Pittsburgh, PA (Metro Ethernet & ISP)
http://puluka.com/home
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Re: LAG between Juniper and Cisco Router

‎05-20-2016 07:33 AM

HI,

Greeting !!!

 

"set interfaces ae0 aggregated-ether-options link-speed 1g" is not require. "ae" bundle set/adjuest link-speed as per available members/child links.

I can not comment why you configure "inet mtu". As a standard practice mtu should set on "ae" bundle globle hierarchy.

 

Comming to your actual issue,

Is there any intermediate NEs are in between like transmission device or any L1/L2 devices. If Yes, then member links can not goes off (down) physically. Due to which router understand link is UP and he push the traffc on all members links which cause traffic impact. To avoid such condition, I recommand to configure LACP "active" on both devices.

Remaining configuration looks fine at Juniper side, however, I cannot confirm the other end device configuration as that is not posted in forum.

 

Cheers 🙂

Vinay

Regards,
Vinay
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