Hi,
I am not aware of any method to have different EXP markings on inner and outer MPLS headers.
However, in an explicit-null label design, the inner EXP marking is not relevant IMHO, as traffic will be classified based on the outer EXP.
The inner EXP can be altered using rewrite rules at the penultimate hop.
Curious about the use-case for this requirement.
Cheers,
------------------------------
Ashvin
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Original Message:
Sent: 07-15-2021 07:52
From: Unknown User
Subject: How do you set the EXP bits of an L3VPN's inner MPLS header?
Hi Ashvin.
So there isn't away to have the EXP fields of both headers different?
Thanks,
Deepak
Original Message:
Sent: 07-15-2021 07:18
From: Ashvin
Subject: How do you set the EXP bits of an L3VPN's inner MPLS header?
Hi,
Inner MPLS EXP marking is copied from outer MPLS EXP.
Example below of pkt capture for L3VPN traffic:
MultiProtocol Label Switching Header, Label: 262141, Exp: 5, S: 0, TTL: 64 0011 1111 1111 1111 1101 .... .... .... = MPLS Label: 262141 .... .... .... .... .... 101. .... .... = MPLS Experimental Bits: 5 .... .... .... .... .... ...0 .... .... = MPLS Bottom Of Label Stack: 0 .... .... .... .... .... .... 0100 0000 = MPLS TTL: 64MultiProtocol Label Switching Header, Label: 16, Exp: 5, S: 1, TTL: 64 0000 0000 0000 0001 0000 .... .... .... = MPLS Label: 16 .... .... .... .... .... 101. .... .... = MPLS Experimental Bits: 5 .... .... .... .... .... ...1 .... .... = MPLS Bottom Of Label Stack: 1 .... .... .... .... .... .... 0100 0000 = MPLS TTL: 64Internet Protocol Version 4, Src: 192.168.100.1, Dst: 192.168.102.10
Cheers,
------------------------------
Ashvin
Original Message:
Sent: 07-15-2021 06:39
From: Unknown User
Subject: How do you set the EXP bits of an L3VPN's inner MPLS header?
Hi Ashvin.
Thanks for the reply.
The rewrite rule would set the EXP bits of the outer MPLS header, but I'm interested in setting the EXP bits of the inner MPLS header.
Thanks,
Deepak
Original Message:
Sent: 07-15-2021 05:54
From: Ashvin
Subject: How do you set the EXP bits of an L3VPN's inner MPLS header?
Hi,
EXP bits on MPLS header is set by CoS rewrite rules.
I believe, there are some default EXP rewrite rules on junos which can be verified by:
> show class-of-service rewrite-rule type exp
Which exp code-points are written in the MPLS header depends on which Forwarding Class (FC) that traffic is in, which is determined by CoS classifiers.
You would be able to set the FC using Firewall filter (MultiField Classifier) for a particular flow.
Hope this helps.
Cheers,
------------------------------
Ashvin
Original Message:
Sent: 07-15-2021 05:35
From: Unknown User
Subject: How do you set the EXP bits of an L3VPN's inner MPLS header?
Hi.
In a basic L3VPN setup, I'm trying to configure an ingress PE to set the EXP bits of the inner MPLS header of traffic it sends to remote PEs.
I'm trying to configure an IP firewall filter on the ingress (CE-facing) interface of the ingress PE, but I see not firewall action to set outgoing EXP bits (I only see an action to set DSCP bits).
So I have two questions:
1: Are the IP Precedence bits of the encapsulated IP header copied to the EXP bits of the inner MPLS header by default?
2: How do I set the EXP bits of the inner MPLS header?
I'm testing on a VMX.
Many Thanks,
Deepak
Juniper Business Use Only