[bess] Re: label scheme in EVPN A-D per EVI routes

2025-06-17 Thread Jeffrey (Zhaohui) Zhang 
Hi Ali,

I want to come back to this thread because of what Sasha pointed out in 
https://mailarchive.ietf.org/arch/msg/bess/FmYtsY6xA1GBRStZ2dZH5YhunyQ/.

This email was about the following text:

   Note that the above allows the Ethernet A-D per EVI route to be
   advertised with one of the following granularities:

   *  One Ethernet A-D route per  tuple per
  MAC-VRF.  This is applicable when the PE uses MPLS-based
  disposition with VID translation or may be applicable when the PE
  uses MAC-based disposition with VID translation.

   *  One Ethernet A-D route for each  per MAC-VRF (where the
  Ethernet Tag ID is set to 0).  This is applicable when the PE uses
  MAC-based disposition or MPLS-based disposition without VID
  translation.

Our earlier conversation concluded that the VID would not be used to identify 
the BT. But apparently, an implementation could advertise the same label for 
different Tag IDs and rely on  to identify the BT in the case of no 
VID translation.

Therefore, another bullet point could be added to the above.

Thanks.
Jeffrey




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From: Ali Sajassi (sajassi) 
Sent: Monday, June 2, 2025 6:31 PM
To: Jeffrey (Zhaohui) Zhang ; [email protected]
Subject: Re: label scheme in EVPN A-D per EVI routes

[External Email. Be cautious of content]

Hi Jeffrey,

Please see my comments below


From: Jeffrey (Zhaohui) Zhang 
mailto:[email protected]>>
Date: Wednesday, May 28, 2025 at 1:45 PM
To: [email protected] mailto:[email protected]>>
Subject: [bess] label scheme in EVPN A-D per EVI routes
Hi,

This is another question coming out of the shepherd review of RFC7432bis.

In the following text, what does "disposition" mean exactly? Just "forwarding"?

Ali> It means forwarding in the disposition direction – i.e., from core to 
access

   Note that the above allows the Ethernet A-D per EVI route to be
   advertised with one of the following granularities:

   *  One Ethernet A-D route per  tuple per
  MAC-VRF.  This is applicable when the PE uses MPLS-based
  disposition with VID translation or may be applicable when the PE
  uses MAC-based disposition with VID translation.

Is it that the label alone will identify the outgoing AC w/o a MAC lookup, and 
it can also identify bridge table in which a MAC lookup is done?

Ali> That’s correct.
Zzh> The key here is that non-zero Tag is used, and labels are different based 
on the tag value so that in the MAC lookup case the label can lead to the BT.
Zzh> I suppose this is only for vlan-aware bundle.

Ali>> Exactly! In case of MAC lookup, this applies to VLAN-aware bundle or 
vlan-based service interfaces  where label identifies specific BT of a MAC-VRF 
(I am adding some text to say that).


   *  One Ethernet A-D route for each  per MAC-VRF (where the
  Ethernet Tag ID is set to 0).  This is applicable when the PE uses
  MAC-based disposition or MPLS-based disposition without VID
  translation.

Is it that the VID in the packet plus the label will determine the outgoing AC 
or the bridge table in which a MAC lookup is done?

Ali> In case of MAC-based disposition (i.e., using MAC lookup), the received 
MPLS label identifies the bridge table, and the MAC lookup is performed there. 
In case of MPLS-based disposition, the received MPLS label identifies, egress 
port; however, no VID translation can be done for that port. I will change “or” 
or “or,” in the above sentence.

Zzh> Initially I was wondering if this was also applicable to the vlan-aware 
bundle case, hence the question – would the incoming VID also be used to 
determine the BT in the mac-based forwarding.

Ali>> That’s correct. The applicability is for vlan-bundle or port-based 
service interfaces (I am adding some text to say that). Since Ethernet Tag ID 
is set to zero in this case, vlan look up is not performed to identify BT.

Zzh> Now I suppose it is really just for the vlan-bundle case and the label 
alone determines the BT. If that’s the case, then the whole text here is only 
adding confusion, because the route is always one per  
tuple per MAC-VRF – in the vlan-bundle case the Tag ID is 0.

Ali>> Yes, but when you set the Tag ID to zero, then the granularity is at the 
 level and that’s what the text says.

Cheers,
Ali

Zzh> Is my understanding correct?
Zzh> Thanks.
Zzh> Jeffrey


Thanks.
Jeffrey


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[bess] Re: label scheme in EVPN A-D per EVI routes

2025-06-02 Thread Ali Sajassi (sajassi) 
Hi Jeffrey,

Please see my comments below


From: Jeffrey (Zhaohui) Zhang 
mailto:[email protected]>>
Date: Wednesday, May 28, 2025 at 1:45 PM
To: [email protected] mailto:[email protected]>>
Subject: [bess] label scheme in EVPN A-D per EVI routes
Hi,

This is another question coming out of the shepherd review of RFC7432bis.

In the following text, what does "disposition" mean exactly? Just "forwarding"?

Ali> It means forwarding in the disposition direction – i.e., from core to 
access

   Note that the above allows the Ethernet A-D per EVI route to be
   advertised with one of the following granularities:

   *  One Ethernet A-D route per  tuple per
  MAC-VRF.  This is applicable when the PE uses MPLS-based
  disposition with VID translation or may be applicable when the PE
  uses MAC-based disposition with VID translation.

Is it that the label alone will identify the outgoing AC w/o a MAC lookup, and 
it can also identify bridge table in which a MAC lookup is done?

Ali> That’s correct.
Zzh> The key here is that non-zero Tag is used, and labels are different based 
on the tag value so that in the MAC lookup case the label can lead to the BT.
Zzh> I suppose this is only for vlan-aware bundle.

Ali>> Exactly! In case of MAC lookup, this applies to VLAN-aware bundle or 
vlan-based service interfaces  where label identifies specific BT of a MAC-VRF 
(I am adding some text to say that).


   *  One Ethernet A-D route for each  per MAC-VRF (where the
  Ethernet Tag ID is set to 0).  This is applicable when the PE uses
  MAC-based disposition or MPLS-based disposition without VID
  translation.

Is it that the VID in the packet plus the label will determine the outgoing AC 
or the bridge table in which a MAC lookup is done?

Ali> In case of MAC-based disposition (i.e., using MAC lookup), the received 
MPLS label identifies the bridge table, and the MAC lookup is performed there. 
In case of MPLS-based disposition, the received MPLS label identifies, egress 
port; however, no VID translation can be done for that port. I will change “or” 
or “or,” in the above sentence.

Zzh> Initially I was wondering if this was also applicable to the vlan-aware 
bundle case, hence the question – would the incoming VID also be used to 
determine the BT in the mac-based forwarding.

Ali>> That’s correct. The applicability is for vlan-bundle or port-based 
service interfaces (I am adding some text to say that). Since Ethernet Tag ID 
is set to zero in this case, vlan look up is not performed to identify BT.

Zzh> Now I suppose it is really just for the vlan-bundle case and the label 
alone determines the BT. If that’s the case, then the whole text here is only 
adding confusion, because the route is always one per  
tuple per MAC-VRF – in the vlan-bundle case the Tag ID is 0.

Ali>> Yes, but when you set the Tag ID to zero, then the granularity is at the 
 level and that’s what the text says.

Cheers,
Ali

Zzh> Is my understanding correct?
Zzh> Thanks.
Zzh> Jeffrey


Thanks.
Jeffrey


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[bess] Re: label scheme in EVPN A-D per EVI routes

2025-06-02 Thread Jeffrey (Zhaohui) Zhang 
Hi Ali,



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From: Ali Sajassi (sajassi) 
Sent: Wednesday, May 28, 2025 6:27 PM
To: Jeffrey (Zhaohui) Zhang ; [email protected]
Subject: Re: label scheme in EVPN A-D per EVI routes

[External Email. Be cautious of content]

Hi Jeffrey,

Please see my replies inline.

From: Jeffrey (Zhaohui) Zhang 
mailto:[email protected]>>
Date: Wednesday, May 28, 2025 at 1:45 PM
To: [email protected] mailto:[email protected]>>
Subject: [bess] label scheme in EVPN A-D per EVI routes
Hi,

This is another question coming out of the shepherd review of RFC7432bis.

In the following text, what does "disposition" mean exactly? Just "forwarding"?

Ali> It means forwarding in the disposition direction – i.e., from core to 
access

   Note that the above allows the Ethernet A-D per EVI route to be
   advertised with one of the following granularities:

   *  One Ethernet A-D route per  tuple per
  MAC-VRF.  This is applicable when the PE uses MPLS-based
  disposition with VID translation or may be applicable when the PE
  uses MAC-based disposition with VID translation.

Is it that the label alone will identify the outgoing AC w/o a MAC lookup, and 
it can also identify bridge table in which a MAC lookup is done?

Ali> That’s correct.
Zzh> The key here is that non-zero Tag is used, and labels are different based 
on the tag value so that in the MAC lookup case the label can lead to the BT.
Zzh> I suppose this is only for vlan-aware bundle.

   *  One Ethernet A-D route for each  per MAC-VRF (where the
  Ethernet Tag ID is set to 0).  This is applicable when the PE uses
  MAC-based disposition or MPLS-based disposition without VID
  translation.

Is it that the VID in the packet plus the label will determine the outgoing AC 
or the bridge table in which a MAC lookup is done?

Ali> In case of MAC-based disposition (i.e., using MAC lookup), the received 
MPLS label identifies the bridge table, and the MAC lookup is performed there. 
In case of MPLS-based disposition, the received MPLS label identifies, egress 
port; however, no VID translation can be done for that port. I will change “or” 
or “or,” in the above sentence.

Zzh> Initially I was wondering if this was also applicable to the vlan-aware 
bundle case, hence the question – would the incoming VID also be used to 
determine the BT in the mac-based forwarding.

Zzh> Now I suppose it is really just for the vlan-bundle case and the label 
alone determines the BT. If that’s the case, then the whole text here is only 
adding confusion, because the route is always one per  
tuple per MAC-VRF – in the vlan-bundle case the Tag ID is 0.

Zzh> Is my understanding correct?
Zzh> Thanks.
Zzh> Jeffrey


Thanks.
Jeffrey


Juniper Business Use Only

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[bess] Re: label scheme in EVPN A-D per EVI routes

2025-05-28 Thread Ali Sajassi (sajassi) 
Hi Jeffrey,

Please see my replies inline.

From: Jeffrey (Zhaohui) Zhang 
Date: Wednesday, May 28, 2025 at 1:45 PM
To: [email protected] 
Subject: [bess] label scheme in EVPN A-D per EVI routes
Hi,

This is another question coming out of the shepherd review of RFC7432bis.

In the following text, what does "disposition" mean exactly? Just "forwarding"?

Ali> It means forwarding in the disposition direction – i.e., from core to 
access

   Note that the above allows the Ethernet A-D per EVI route to be
   advertised with one of the following granularities:

   *  One Ethernet A-D route per  tuple per
  MAC-VRF.  This is applicable when the PE uses MPLS-based
  disposition with VID translation or may be applicable when the PE
  uses MAC-based disposition with VID translation.

Is it that the label alone will identify the outgoing AC w/o a MAC lookup, and 
it can also identify bridge table in which a MAC lookup is done?

Ali> That’s correct.


   *  One Ethernet A-D route for each  per MAC-VRF (where the
  Ethernet Tag ID is set to 0).  This is applicable when the PE uses
  MAC-based disposition or MPLS-based disposition without VID
  translation.

Is it that the VID in the packet plus the label will determine the outgoing AC 
or the bridge table in which a MAC lookup is done?

Ali> In case of MAC-based disposition (i.e., using MAC lookup), the received 
MPLS label identifies the bridge table, and the MAC lookup is performed there. 
In case of MPLS-based disposition, the received MPLS label identifies, egress 
port; however, no VID translation can be done for that port. I will change “or” 
or “or,” in the above sentence.


Thanks.
Jeffrey


Juniper Business Use Only

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