[bess] Re: comments on draft-ietf-bess-rfc7432bis

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Just resent this draft to the mailing list.
Appreciate for the clarification from authors.
Thanks,
Sandy












Original


From: 张征
To: [e-mail] <[e-mail]>;[e-mail] <[e-mail]>;[e-mail] <[e-mail]>;[e-mail] <[e-mail]>;
Cc: [e-mail] <[e-mail]>;
Date: 2024年12月05日 08:36
Subject: [bess] comments on draft-ietf-bess-rfc7432bis


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Hi, 
I have some comments about the flow label, could you please help me understand it more clearly:

1. Can the flow label be used with other bottom label, such as the GAL used in RFC9489. When both of the labels are used, the flow label is no longer the bottom label, right?

2. In the last paragraph of section 7.11.2, 
"......  If there is a mismatch, the local PE MUST NOT add the
   remote PE as the EVPN destination for any of the corresponding
   service instances.  The Flow label capability signaling is further
   described in Section 18.1."
From this sentense, we know that if the PE supports flow label, but the remote PE doesn't, or the PE doesn't support flow label, but the remote PE does, then in both cases, the remote PE will be excluded as an EVPN destination.

But in section 18.1:
"   *  When F-bit is set to 1, the PE announces the capability of both
      sending and receiving flow label for known unicast.

      If the PE is capable itself of supporting Flow Label, then:

      -  upon receiving the F-bit set (F=1) from a remote PE, it MUST
         send known unicast packets to that PE with Flow labels;

      -  alternately, upon receiving the F-bit unset (F=0) from a
         remote PE, it MUST NOT send known unicast packets to that PE
         with Flow labels."
From the description, it seems that when PE supports flow label, but the remote PE doesn't support flow label, the remote PE will not be excluded as an EVPN destination, do I understand it correctly?

3. for the sentence in section 18.1:
"      When a PE that doesn't support flow label, receives the F-bit set
      (F=1) from a remote PE, it takes the following actions: a) it
      notifies the operator and b) it excludes the remote PE as the EVPN
      destination for any of the corresponding service instances.  ......"
Regarding the action b, does it mean that the remote PE's RT3 routes will be excluded from all the services, or only for that remote PE's RT2/RT1 routes?
Will the remote PE's RT4 routes be excluded from these services?

Thank you very much!
Best regards,
Sandy