[j-nsp] ex-series: etherchannel bpdu loop ?

[Alexandre Snarskii]

On Wed, Mar 18, 2009 at 02:38:39PM -0800, Christopher E. Brown wrote:
> 
> 
> Check your cisco side configs, that config looks like a cisco 
> "unconditional channel", not a lacp channel.

Yes, on Cisco side it's unconditional etherchannel. 
But on Juniper side it's unconditional etherchannel too: 

interface ge-0/0/15 {
 802.3ad ae0; /* no lacp involved */
} 

We're using lots of those unconditional links between Cisco and
M/MX-series and never had problems like that one.


> 
> channel-group 1 mode on == HARD ETHER CHANNEL
> channel-group 1 mode active == Active LACP or PAGP (depends on platform)
> 
> 
> Some will need
> 
> channel-protocol lacp
> channel-group 1 mode active
> 
> others default to lacp


> 
> 
> 
> 
> Keegan.Holley at sungard.com wrote:
> >I'm not terribly well versed in ex configuration, ( I think we're still 
> >evaluating them) but it looks like you are trying to negotiate on the ex 
> >end and then have it set on the cisco side so there may be a point in time 
> >when the links aren't aggergated on the juniper side where traffic is 
> >looped.
> >
> >
> >
> >
> >
> >From:
> >Alexandre Snarskii <snar at snar.spb.ru>
> >To:
> >Juniper-NSP Mailing list <juniper-nsp at puck.nether.net>
> >Date:
> >03/18/2009 01:43 PM
> >Subject:
> >[j-nsp] ex-series: etherchannel bpdu loop ?
> >Sent by:
> >juniper-nsp-bounces at puck.nether.net
> >
> >
> >
> >
> >Hi!
> >
> >After power failure on one of our pop's we faced strange problem: 
> >etherchannel between juniper ex-4200 and cisco 2960g started to 
> >flap. By logs I saw that Cisco determined 'etherchannel 
> >misconfiguration' condition, shuts down both ports of channel,
> >then, after errdisable timeout, tried to set them up, but then 
> >again detects etherchannel misconfiguration and so on and on... 
> >
> >By Cisco documentation, etherchannel misconfiguration means 
> >that BPDU's sent on one ports of etherchannel returned back 
> >via another port. And forwarding of those BPDU from one
> >LAG member interface to another (rstp is disabled on juniper)
> >smells like an error in JunOS... 
> >
> >Workaround: delete interfaces from LAG on Juniper, commit,
> >add interfaces to LAG, commit. 
> >
> >PS: Configuration is pretty straightforward on both sides: 
> >
> >Juniper: 
> >
> >snar at SW006-201> show configuration interfaces ae0 
> >aggregated-ether-options {
> >    minimum-links 1;
> >    link-speed 1g;
> >}
> >unit 0 {
> >    family ethernet-switching {
> >        port-mode trunk;
> >        vlan {
> >            members all;
> >        }
> >    }
> >}
> >snar at SW006-201> show configuration interfaces ge-0/0/15 
> >ether-options {
> >    speed {
> >        1g;
> >    }
> >    802.3ad ae0;
> >}
> >snar at SW006-201> show configuration protocols 
> >[....]
> >stp {
> >    disable;
> >}
> >rstp {
> >    disable;
> >}
> >mstp {
> >    disable;
> >}
> >
> >
> >Cisco: 
> >
> >Cisco#show runn int po1
> >interface Port-channel1
> > switchport mode trunk
> > mvr type source
> >Cisco#show runn int gi 0/23
> >interface GigabitEthernet0/23
> > switchport mode trunk
> > load-interval 30
> > channel-group 1 mode on
> >
> >
> >_______________________________________________
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> >https://puck.nether.net/mailman/listinfo/juniper-nsp
> >
> >
> >
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