nanog mailing list archives

Re: Question about EX - SRX redundancy


From: Anurag Bhatia <me () anuragbhatia com>
Date: Thu, 2 Apr 2015 20:47:03 +0530

Hi


I thought cross chassis lag is supposed by the use of reth bundled at SRX
end. I read this is basically the major difference in reth Vs ae bundle in
SRX.


Interesting factor here is that ae bundles can spread across multiple EX
chassis in a virtual chassis environment but this cannot be the case with
ae bundles in SRX.




Thanks.

On Thu, Apr 2, 2015 at 7:59 PM, Bill Blackford <bblackford () gmail com> wrote:

It's my understanding that a cross chassis LAG is not supported. If there
is a way, I'm not aware of it. I'm running the same set up as your working
example in my locations and for now, this suits my requirements.

Sent from my iPhone

On Apr 2, 2015, at 07:12, Anurag Bhatia <me () anuragbhatia com> wrote:

Hello everyone!




I have got two Juniper EX series switches (on virtual chassis) and two
SRX
devices on native clustering.


I am trying to have a highly available redundancy between them with
atleast
2Gbps capacity all the time but kind of failing. I followed Juniper's
official page here
<http://kb.juniper.net/InfoCenter/index?page=content&id=KB22474> as
well as
this detailed forum link here
<
http://forums.juniper.net/t5/SRX-Services-Gateway/Best-way-of-redundancy-between-SRX-and-EX/td-p/181365

.


I wish to have a case where devices are connected criss cross and
following
the documentation I get two ae bundles in EX side and one single reth
bundle on SRX side. Both ae bundles on EX side have identical
configuration
and VLAN has both ae interfaces called up.


If I do not go for criss cross connectivity like this:



EX0  (ae1) >> Two Patches to SRX0 (reth1)
EX1   (ae2)  >> Two Patches to SRX1 (reth1)


Then it works all well and redundancy works fine. In this case as long
as 1
out of 4 patch is connected connectivity stays live but this has trade
off
that if one EX goes down then I cannot make use of other corresponding
SRX.

If I do criss connectivity, something like:


EX0 (ae1) >> Two Patches to SRX0 (reth1)
EX0 (ae1) >> One patch to SRX1 (reth1)

EX1 (ae2)  >> Two Patches to SRX1 (reth1)
EX1 (ae2)  >> One patch to SRX0 (reth1)


In this config system behaves very oddly with one ae pair (and it's
corresponding physical ports) working well while failover to other ae
bundle fails completely.



I was wondering if someone can point me out here.




Appreciate your time and help!





--


Anurag Bhatia
anuragbhatia.com

Linkedin <http://in.linkedin.com/in/anuragbhatia21> | Twitter
<https://twitter.com/anurag_bhatia>
Skype: anuragbhatia.com

PGP Key Fingerprint: 3115 677D 2E94 B696 651B 870C C06D D524 245E 58E2




-- 


Anurag Bhatia
anuragbhatia.com

Linkedin <http://in.linkedin.com/in/anuragbhatia21> | Twitter
<https://twitter.com/anurag_bhatia>
Skype: anuragbhatia.com

PGP Key Fingerprint: 3115 677D 2E94 B696 651B 870C C06D D524 245E 58E2


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