[j-nsp] BFD timers for OSPF - MX80 - 10.3R2.11

Doug Hanks dhanks at juniper.net
Thu Mar 3 17:27:27 EST 2011


We generally recommend 150ms to most customers.  The added benefit of going from 150ms to 50ms is generally not enough to warrant the move.

-----Original Message-----
From: juniper-nsp-bounces at puck.nether.net [mailto:juniper-nsp-bounces at puck.nether.net] On Behalf Of Andy Harding
Sent: Thursday, March 03, 2011 10:07 AM
To: David Ball
Cc: juniper-nsp at puck.nether.net
Subject: Re: [j-nsp] BFD timers for OSPF - MX80 - 10.3R2.11

We are using bfd on mx80 with 300ms timers and no problems. Only 2 or 3 sessions per box however. 

--

Regards

Andy Harding
Internet Connections Ltd

Phone: 0870 803 1868
Mobile: 07813 975459
Fax: 0870 803 1781
Web: www.inetc.co.uk
Email: andy at inetc.co.uk

On 3 Mar 2011, at 17:53, David Ball <davidtball at gmail.com> wrote:

>  Ah, that might help explain it.  And shame on me for not checking
> 'sh pfe statistics traffic protocol bfd', which of course shows none
> received or absorbed.
>  I'll only have 2 sessions on each MX80, so I think I might leave it
> enabled, but may toy with the interval.  I'm expecting the control
> plane to be kinda bored on these guys, so we'll see what it can
> handle.
>  Thanks, Egor.
> 
> David
> 
> 
> On 3 March 2011 10:42, Egor Zimin <lesnix at gmail.com> wrote:
>> Hello, David
>> 
>> It looks like BFD implementation in MX80 is not distributed. At this
>> moment I have a case in JTAC. The case is opened yet, however, it
>> _looks_like_ bfd is not distributed.
>> Probably because of this BFD echomode is not supported. And using 30ms
>> timers for BFD ControlPackets can be not so easy task for RE's CPU.
>> 
>> Because of this I don't see much sense to use BFD on MX80 at this moment.
>> 
>> 2011/3/3 David Ball <davidtball at gmail.com>:
>>> MX80s running 10.3R2.11
>>> 
>>> For those of you using BFD for OSPF, how low have you been able to
>>> set your minimum-interval timer?  I have a pair of MX80s connected via
>>> XFPs and 1m patch cables and with my hellos set to 30ms and multiplier
>>> set to 3, I'm seeing failures.  I haven't disabled distributed ppm.
>>> Moving to 50ms hellos seems to settle things down.  The reason I'm
>>> wondering why I can't get away with lower timers is because when
>>> Juniper proof-of-concepted (yeah, that's a verb) Trio for us (albeit
>>> using MX960s), they used 15ms hellos with a multiplier of 3.
>>> 
>>> Mar  3 10:06:06  router bfdd[1129]: BFDD_TRAP_STATE_DOWN: local
>>> discriminator: 1, new state: down
>>> Mar  3 10:06:06  router rpd[1257]: RPD_OSPF_NBRDOWN: OSPF neighbor
>>> 172.16.1.22 (realm ospf-v2 xe-0/0/2.0 area 0.0.0.0) state changed from
>>> Full to Down due to InActiveTimer (event reason: BFD session timed out
>>> and neighbor was declared dead)
>>> 
>>> 
>>> me at router> show configuration groups bfd-defaults-core-ospf
>>> protocols {
>>>   ospf {
>>>       area 0.0.0.0 {
>>>           interface <*> {
>>>               bfd-liveness-detection {
>>>                   version automatic;
>>>                   minimum-interval 30;
>>>                   multiplier 3;
>>>                   full-neighbors-only;
>>>               }
>>>           }
>>>       }
>>>   }
>>> }
>>> 
>>> me at router> show configuration protocols ospf area 0.0.0.0
>>> interface lo0.0 {
>>>   passive;
>>> }
>>> interface xe-0/0/2.0 {
>>>   apply-groups bfd-defaults-core-ospf;
>>>   node-link-protection;
>>> }
>>> interface xe-0/0/3.0 {
>>>   apply-groups bfd-defaults-core-ospf;
>>>   node-link-protection;
>>> }
>>> 
>>> 
>>> David
>>> _______________________________________________
>>> juniper-nsp mailing list juniper-nsp at puck.nether.net
>>> https://puck.nether.net/mailman/listinfo/juniper-nsp
>>> 
>> 
>> 
>> 
>> --
>> Best regards,
>> Egor Zimin
>> 
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