Hi Muthu, What do you mean by saying “PE2 has MAC-VRF2 and MAC-VRF3, all using the same VLAN”? There can be only a single MAC-VRF per EVI in each PE as stated in the RFC7432bis (cut & pasted below)!!
“A tenant configured for an EVPN service instance (i.e, EVI) on a PE, is instantiated by a single MAC Virtual Routing and Forwarding table (MAC-VRF) on that PE.” Cheers, Ali From: Muthu Arul Mozhi Perumal <muthu.a...@gmail.com> Date: Tuesday, March 25, 2025 at 2:44 AM To: Ali Sajassi (sajassi) <saja...@cisco.com> Cc: bess@ietf.org <bess@ietf.org> Subject: Re: [bess] Re: Originating Router's IP Address in EVPN Hi Ali, My bad, I meant different MAC VRFs (with their own RD/RT) in the example below, all being part of the same EVI, and using the same VLAN (i.e. VLAN-based service). So, PE1 has MAC-VRF1 and PE2 has MAC-VRF2 and MAC-VRF3, all using the same VLAN. If PE2 sends two IMET routes to PE1 (one for each MAC-VRF), then it wouldn't work if the same originating router's IP address is used in both the routes. However, when MAC-VRF3 is in a different PE (say, PE3), then this works fine since PE3 would use a different originating router's IP address in the IMET route it sends. My broader question is, given that the originating router's IP address is used only for route keying, what is the rationale behind saying that "it must remain the same for all EVPN routes advertised by that PE (across all EVIs)."? Also, what should the receiver do: 1. If it receives two IMET routes with the same Ethernet tag and originating routers's IP address? 2. If it receives an IMET route with its own originating router's IP address? I think it is important to clarify 1, 2 for propor interop.. Regards, Muthu On Tue, Mar 25, 2025 at 4:02 AM Ali Sajassi (sajassi) <saja...@cisco.com<mailto:saja...@cisco.com>> wrote: Hi Muthu, What do you mean by “that EVI1 in PE1 has L2 reachability to both EVI2 and EVI3 in PE2.” ??!! EVIs are supposed to be isolated and not overlapping. If connectivity among different EVIs is desired, then IRB solution can be leveraged where you connect different BDs/EVIs via L3 VRF. Cheers, Ali From: Muthu Arul Mozhi Perumal <muthu.a...@gmail.com<mailto:muthu.a...@gmail.com>> Date: Wednesday, March 19, 2025 at 2:20 AM To: bess@ietf.org<mailto:bess@ietf.org> <bess@ietf.org<mailto:bess@ietf.org>> Subject: [bess] Re: Originating Router's IP Address in EVPN Searching further, it looks some vendors already support a configuration option to set the Originating Router's IP address per EVI (with the default being the PE loopback) for the IMET route. Given this, it is difficult to understand the rationale behind this requirement in draft-ietf-bess-rfc7432bis that says "it must remain the same for all EVPN routes advertised by that PE (across all EVIs).".. Now, it says "must" (not MUST), so could be ignored :) Regards, Muthu On Tue, Mar 18, 2025 at 2:41 PM Muthu Arul Mozhi Perumal <muthu.a...@gmail.com<mailto:muthu.a...@gmail.com>> wrote: Hi experts, Consider the foll. EVPN VPLS deployment scenario: PE1(EVI1)----IP/MPLS----PE2(EVI2, EVI3) EV11, EVI2 and EVI3 all use the same Ether Tag (assume VLAN based service for simplicity). EVI1 in PE1 imports the routes (i,e. RTs) from both EV2 and EV3 in PE2, so that EVI1 in PE1 has L2 reachability to both EV2 and EVI3 in PE2. However, looking at draft-ietf-bess-rfc7432bis, it looks this would be a problem for the IMET routes originated by PE2 for EVI2 and EVI3. Section 7.3 describes the IMET route format and says: <snip> For the purpose of BGP route key processing, only the Ethernet Tag ID, IP Address Length, and Originating Router's IP Address fields are considered to be part of the prefix in the NLRI. </snip> Then section 11.1 describes how the IMET is constructed and says: <snip> The Originating Router's IP Address field value MUST be set to an IP address of the PE (e.g., this address may be the PE's loopback address). The IP Address Length field is in bits. The Originating Router's IP address does not need to be a routable address and its purpose is to identify the originator of that EVPN route uniquely. It can be either IPv4 or IPv6 address independent of the BGP next hop address type for that NLRI and it must remain the same for all EVPN routes advertised by that PE across all EVIs. </snip> Given that all EVIs use the same Ethernet TAG, for PE1 to be able to distinguish between the IMET routes originated by PE2 for EVI2 and EVI3 while importing them into EVI1, the Originating Router's IP Address field should be different in those IMET routes. However, draft-ietf-bess-rfc7432bis does not allow it and requires the same Originating Router's IP Address be used by PE2. Why is such a restriction needed? Why can't PE2 use two different (non routable) Originating Router's IP Address for the IMET routes originated for EVI2 and EVI3? Regards, Muthu
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