Re: [j-nsp] Cut-through forwarding statistics on QFX5100

2017-06-23 Thread Saku Ytti 
On 23 June 2017 at 08:39, Vincent Bernat  wrote:

Hey,

> Related question: why isn't cut-through the default mode? Is there any
> downside of this mode (apart from forwarding invalid frames which
> shouldn't matter much nowaday)?

You'll pass errored frames to the network, as you'll only know about
errors after you've sent the frame. In reality this isn't such a big
deal, as we don't guarantee non-brokenness of frames anyhow, generally
devices, even switches, regenerate ethernet frame (because they have
to, if VLAN stack, COS etc changes, so they do it always for
simplicity) on egress and  calculate new FCS on it, so if there is
broken memory on device, we calculate correct FCS on the frame we just
broke.

But also upside on cut-through is very limited, you obviously only can
do cut-through if egress happens to be completely empty, even in
modestly loaded box, you'd often operate store-and-forward. So you
have to have very specific application to see consistent cut-through
behaviour.

-- 
  ++ytti
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Re: [j-nsp] Cut-through forwarding statistics on QFX5100

2017-06-22 Thread Vincent Bernat 
 ❦ 22 juin 2017 00:28 +0200, Thomas Bellman  :

> We have a QFX5100 on which we have enabled cut-throug forwarding
> ('set forwarding-options cut-through').  Now I am curious about
> how effective that is.  Is there any statistics one can dig out
> about how often the switch is able to do cut-through, and how
> often it has to fall back to store-and-forward?  I haven't found
> anything in 'show interfaces extensive', nor any other promising
> 'show' command.

Related question: why isn't cut-through the default mode? Is there any
downside of this mode (apart from forwarding invalid frames which
shouldn't matter much nowaday)?
-- 
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Re: [j-nsp] Cut-through forwarding statistics on QFX5100

2017-06-22 Thread Chris via juniper-nsp 


On 22/06/2017 11:27 PM, Nelson, Brian wrote:

Model: qfx5100-96s-8q
Junos: 14.1X53-D42.3

user@qfx5100-96s# set forwarding-options cut-through ?
Possible completions:
   <[Enter]>Execute this command

accounting   Configure accounting of traffic
analyzer Analyzer options

+ apply-groups Groups from which to inherit configuration data
+ apply-groups-except  Don't inherit configuration data from these groups


Appears to be present on 16.1:

me@switch# set forwarding-options ?
Possible completions:
> access-security  Access security configuration
> accounting   Configure accounting of traffic
> analyzer Analyzer options
+ apply-groups Groups from which to inherit configuration data
+ apply-groups-except  Don't inherit configuration data from these groups
  cut-through  Enable cut-through forwarding
> dhcp-relay   Dynamic Host Configuration Protocol relay 
configuration
> enhanced-hash-keySelect data used in the hash key for Enhanced IP 
Forwarding Engines

> family   Protocol family
> hash-key Select data used in the hash key
> helpers  Port forwarding configuration
> ip-options-protocol-queue  IP Options protocol logical queue parameters
> load-balance Configure load-balancing attributes on the 
forwarding path

> local-bias   Turn on local bias functionality
  no-load-balance-label-capability  Disable load balance label capability
> port-mirroring   Configure port mirroring of traffic
> storm-control-profiles  Storm control profile for this instance
  vrf-fallback Enable vrf-fallback forwarding. This will 
restart PFE


me@switch# run show version
fpc0:
--
Hostname: core
Model: qfx5100-48s-6q
Junos: 16.1R3.10 limited
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Re: [j-nsp] Cut-through forwarding statistics on QFX5100

2017-06-22 Thread Nelson, Brian 
Model: qfx5100-96s-8q
Junos: 14.1X53-D42.3

user@qfx5100-96s# set forwarding-options cut-through ?
Possible completions:
  <[Enter]>Execute this command
> accounting   Configure accounting of traffic
> analyzer Analyzer options
+ apply-groups Groups from which to inherit configuration data
+ apply-groups-except  Don't inherit configuration data from these groups
> dhcp-relay   Dynamic Host Configuration Protocol relay configuration
> enhanced-hash-keySelect data used in the hash key for Enhanced IP 
> Forwarding Engines
> family   Protocol family
> hash-key Select data used in the hash key
> helpers  Port forwarding configuration
> load-balance Configure load-balancing attributes on the forwarding 
> path
> local-bias   Turn on local bias functionality
  no-load-balance-label-capability  Disable load balance label capability
> port-mirroring   Configure port mirroring of traffic
> storm-control-profiles  Storm control profile for this instance
  vrf-fallback Enable vrf-fallback forwarding. This will restart PFE
  |Pipe through a command

Brian Nelson
Dept of CS
UTD

-Original Message-
From: juniper-nsp [mailto:juniper-nsp-boun...@puck.nether.net] On Behalf Of 
Brant Ian Stevens
Sent: Thursday, June 22, 2017 10:24 AM
To: Aaron Gould <aar...@gvtc.com>
Cc: juniper-nsp@puck.nether.net; 'Thomas Bellman' <bell...@nsc.liu.se>
Subject: Re: [j-nsp] Cut-through forwarding statistics on QFX5100

It is readily available in 17.2; not sure about earlier versions.

branto@host# set forwarding-options ?
Possible completions:
 > access-security  Access security configuration
 > accounting   Configure accounting of traffic
 > analyzer Analyzer options
+ apply-groups Groups from which to inherit configuration data
+ apply-groups-except  Don't inherit configuration data from these 
+ groups
   cut-through  Enable cut-through forwarding
 > dhcp-relay   Dynamic Host Configuration Protocol relay 
configuration
 > enhanced-hash-keySelect data used in the hash key for Enhanced IP 
Forwarding Engines
 > family   Protocol family
 > hash-key Select data used in the hash key
 > helpers  Port forwarding configuration
 > ip-options-protocol-queue  IP Options protocol logical queue parameters
 > load-balance Configure load-balancing attributes on the 
forwarding path
 > local-bias   Turn on local bias functionality
 > port-mirroring   Configure port mirroring of traffic
 > storm-control-profiles  Storm control profile for this instance
   vrf-fallback Enable vrf-fallback forwarding. This will 
restart PFE

> Aaron Gould <mailto:aar...@gvtc.com>
> June 22, 2017 at 10:21 AM
> Sorry I don't have an answer... but interestingly, I see this as a hidden 
> command on the cousin ACX5048... is it hidden in the QFX5100 or in plain view 
> using the ? after set forwarding-option ?
>
> I haven't used it nor committed it further so I don't know of its 
> functionality on this ACX5048
>
> {master:0}[edit]
> agould@eng-lab-5048-1# run show version
> fpc0:
> --
> 
> Hostname: eng-lab-5048-1
> Model: acx5048
> Junos: 15.1X54-D20.7
>
> ...
>
> agould@eng-lab-5048-1# set forwarding-options ?
> Possible completions:
>> accounting   Configure accounting of traffic
> + apply-groups Groups from which to inherit configuration data
> + apply-groups-except  Don't inherit configuration data from these 
> + groups
>> dhcp-relay   Dynamic Host Configuration Protocol relay configuration
>> family   Protocol family
>fast-reroute-priority  Fast-reroute repair priority
>> hash-key Select data used in the hash key
>> helpers  Port forwarding configuration
>no-load-balance-label-capability  Disable load balance label 
> capability
>> port-mirroring   Configure port mirroring of traffic
>> sampling Statistical traffic sampling options
>> storm-control-profiles  Storm control profile for this instance
> {master:0}[edit]
> agould@eng-lab-5048-1# set forwarding-options cut-through
>
> {master:0}[edit]
> agould@eng-lab-5048-1# show | compare
> [edit]
> +  forwarding-options {
> +  cut-through;
> +  }
>
>
> - Aaron Gould
>
>
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> Thomas Bellman <mailto:bell...@nsc.liu.se> June 21, 2017 at 6:28 PM 
> -BE

Re: [j-nsp] Cut-through forwarding statistics on QFX5100

2017-06-22 Thread Brant Ian Stevens 

It is readily available in 17.2; not sure about earlier versions.

branto@host# set forwarding-options ?
Possible completions:
> access-security  Access security configuration
> accounting   Configure accounting of traffic
> analyzer Analyzer options
+ apply-groups Groups from which to inherit configuration data
+ apply-groups-except  Don't inherit configuration data from these groups
  cut-through  Enable cut-through forwarding
> dhcp-relay   Dynamic Host Configuration Protocol relay 
configuration
> enhanced-hash-keySelect data used in the hash key for Enhanced IP 
Forwarding Engines

> family   Protocol family
> hash-key Select data used in the hash key
> helpers  Port forwarding configuration
> ip-options-protocol-queue  IP Options protocol logical queue parameters
> load-balance Configure load-balancing attributes on the 
forwarding path

> local-bias   Turn on local bias functionality
> port-mirroring   Configure port mirroring of traffic
> storm-control-profiles  Storm control profile for this instance
  vrf-fallback Enable vrf-fallback forwarding. This will 
restart PFE



Aaron Gould 
June 22, 2017 at 10:21 AM
Sorry I don't have an answer... but interestingly, I see this as a hidden 
command on the cousin ACX5048... is it hidden in the QFX5100 or in plain view 
using the ? after set forwarding-option ?

I haven't used it nor committed it further so I don't know of its functionality 
on this ACX5048

{master:0}[edit]
agould@eng-lab-5048-1# run show version
fpc0:
--
Hostname: eng-lab-5048-1
Model: acx5048
Junos: 15.1X54-D20.7

...

agould@eng-lab-5048-1# set forwarding-options ?
Possible completions:

accounting   Configure accounting of traffic

+ apply-groups Groups from which to inherit configuration data
+ apply-groups-except  Don't inherit configuration data from these groups

dhcp-relay   Dynamic Host Configuration Protocol relay configuration
family   Protocol family

   fast-reroute-priority  Fast-reroute repair priority

hash-key Select data used in the hash key
helpers  Port forwarding configuration

   no-load-balance-label-capability  Disable load balance label capability

port-mirroring   Configure port mirroring of traffic
sampling Statistical traffic sampling options
storm-control-profiles  Storm control profile for this instance

{master:0}[edit]
agould@eng-lab-5048-1# set forwarding-options cut-through

{master:0}[edit]
agould@eng-lab-5048-1# show | compare
[edit]
+  forwarding-options {
+  cut-through;
+  }


- Aaron Gould


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Thomas Bellman 
June 21, 2017 at 6:28 PM
-BEGIN PGP SIGNED MESSAGE-
Hash: SHA1

We have a QFX5100 on which we have enabled cut-throug forwarding
('set forwarding-options cut-through'). Now I am curious about
how effective that is. Is there any statistics one can dig out
about how often the switch is able to do cut-through, and how
often it has to fall back to store-and-forward? I haven't found
anything in 'show interfaces extensive', nor any other promising
'show' command.

The dream would of course be to get counters for every combination
of ingress and egress interface, but I would be happy to get just
counters for just ingress or egress, or even just a total for the
entire system.

The switch is running Junos 17.2R1 if that matters.


- -- 
Thomas Bellman, National Supercomputer Centre, Linköping Univ., Sweden

"We don't understand the software, and ! bellman @ nsc . liu . se
sometimes we don't understand the hardware, !
but we can *see* the blinking lights!" ! Make Love -- Nicht Wahr!
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--

--
Regards,
--
Brant I. Stevens,

Re: [j-nsp] Cut-through forwarding statistics on QFX5100

2017-06-22 Thread Aaron Gould 
Sorry I don't have an answer... but interestingly, I see this as a hidden 
command on the cousin ACX5048... is it hidden in the QFX5100 or in plain view 
using the ? after set forwarding-option ?

I haven't used it nor committed it further so I don't know of its functionality 
on this ACX5048

{master:0}[edit]
agould@eng-lab-5048-1# run show version
fpc0:
--
Hostname: eng-lab-5048-1
Model: acx5048
Junos: 15.1X54-D20.7

...

agould@eng-lab-5048-1# set forwarding-options ?
Possible completions:
> accounting   Configure accounting of traffic
+ apply-groups Groups from which to inherit configuration data
+ apply-groups-except  Don't inherit configuration data from these groups
> dhcp-relay   Dynamic Host Configuration Protocol relay configuration
> family   Protocol family
  fast-reroute-priority  Fast-reroute repair priority
> hash-key Select data used in the hash key
> helpers  Port forwarding configuration
  no-load-balance-label-capability  Disable load balance label capability
> port-mirroring   Configure port mirroring of traffic
> sampling Statistical traffic sampling options
> storm-control-profiles  Storm control profile for this instance
{master:0}[edit]
agould@eng-lab-5048-1# set forwarding-options cut-through

{master:0}[edit]
agould@eng-lab-5048-1# show | compare
[edit]
+  forwarding-options {
+  cut-through;
+  }


- Aaron Gould


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