From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from firstgate.proxmox.com (firstgate.proxmox.com [IPv6:2a01:7e0:0:424::9]) by lore.proxmox.com (Postfix) with ESMTPS id C28941FF14C for ; Fri, 15 May 2026 12:26:20 +0200 (CEST) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id 5F86919065; Fri, 15 May 2026 12:26:02 +0200 (CEST) From: Hannes Laimer To: pve-devel@lists.proxmox.com Subject: [PATCH pve-docs v6 9/9] sdn: add bgp fabric section Date: Fri, 15 May 2026 12:25:00 +0200 Message-ID: <20260515102500.216264-10-h.laimer@proxmox.com> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260515102500.216264-1-h.laimer@proxmox.com> References: <20260515102500.216264-1-h.laimer@proxmox.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Bm-Milter-Handled: 55990f41-d878-4baa-be0a-ee34c49e34d2 X-Bm-Transport-Timestamp: 1778840699833 X-SPAM-LEVEL: Spam detection results: 0 AWL 0.082 Adjusted score from AWL reputation of From: address BAYES_00 -1.9 Bayes spam probability is 0 to 1% DMARC_MISSING 0.1 Missing DMARC policy KAM_DMARC_STATUS 0.01 Test Rule for DKIM or SPF Failure with Strict Alignment SPF_HELO_NONE 0.001 SPF: HELO does not publish an SPF Record SPF_PASS -0.001 SPF: sender matches SPF record Message-ID-Hash: VAAK7KWR26SFOFDOYBEDIPBBCAOXDVJE X-Message-ID-Hash: VAAK7KWR26SFOFDOYBEDIPBBCAOXDVJE X-MailFrom: h.laimer@proxmox.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; loop; banned-address; emergency; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header X-Mailman-Version: 3.3.10 Precedence: list List-Id: Proxmox VE development discussion List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: Signed-off-by: Hannes Laimer --- pvesdn.adoc | 103 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 103 insertions(+) diff --git a/pvesdn.adoc b/pvesdn.adoc index 279dc6b..1b0815c 100644 --- a/pvesdn.adoc +++ b/pvesdn.adoc @@ -1120,6 +1120,109 @@ The trailing `permit` entry with no match is the FRR pattern for "allow everything else"; without it the implicit deny at the end of the route map would drop all unmatched routes. +[[pvesdn_bgp]] +BGP +~~~ + +BGP (Border Gateway Protocol) can be used as an eBGP unnumbered fabric. Each +node has its own Autonomous System Number (ASN) and peers with its neighbors +over physical interfaces without requiring IP addresses on the fabric links. + +Configuration options: + +[[pvesdn_bgp_fabric]] +On the Fabric +^^^^^^^^^^^^^ + +IPv4 Prefix:: IPv4 CIDR network range (e.g., 192.0.2.0/24) used to verify that +all node IPv4 addresses (BGP router-IDs) are contained within this prefix. + +IPv6 Prefix:: IPv6 CIDR network range (e.g., 2001:db8::/64) used to verify that +all node IPv6 addresses in the fabric are contained within this prefix. + +BFD:: Enable Bidirectional Forwarding Detection on all peering sessions in this +fabric. BFD provides fast failure detection for links between nodes. + +Route Filter:: A prefix list applied to the fabric peer-group's inbound +direction. When set, this prefix list replaces the implicit "must be within the +fabric prefix" filter. Useful to widen the accepted range (e.g. accept +additional non-fabric prefixes redistributed via the fabric) or to use a more +expressive match. References a prefix list defined under SDN. + +Incoming Route Map:: A route map chained from the fabric peer-group's implicit +inbound filter via FRR's `call` action. Only prefixes that have already passed +the implicit prefix check (or the Route Filter override) reach this route map. +Useful to transform or further narrow accepted routes (e.g. adjust community or +local-preference), but cannot widen the accepted set. Use Route Filter to +override the implicit filter. References a route map defined under SDN. + +Outgoing Route Map:: A route map applied to the fabric peer-group's outbound +direction. Used to transform or filter what is announced to fabric neighbors. +References a route map defined under SDN. + +Redistribute:: Which other-protocol routes the BGP router on each node should +redistribute into the fabric. Supported sources are `connected`, `kernel`, +`static`, and `ospf`. An optional per-source route map can be attached to shape +the redistributed routes before they are announced. + +NOTE: At least one of IPv4 Prefix or IPv6 Prefix must be configured. + +[[pvesdn_bgp_node]] +On the Node +^^^^^^^^^^^ + +Options that are available on every node that is part of a fabric: + +Node:: Select the node which will be added to the fabric. Only nodes that are +currently in the cluster will be shown. + +ASN:: BGP Autonomous System Number for this node. It is recommended to use +private ASN numbers (64512-65534 for 16-bit, 4200000000-4294967294 for 32-bit). + +IPv4:: A unique IPv4 address for this node, also used as the BGP router-id. +Required when the fabric has an IPv4 prefix configured; each node in the same +fabric must have a different address. + +IPv6:: IPv6 address for this node. If only an IPv6 address is configured +(without an IPv4 address), the BGP router-id is derived from it via a FNV-1a +hash. + +Interfaces:: Specify the interfaces used to establish peering connections with +other BGP nodes. These interfaces run BGP unnumbered (no IP address assignment +needed). When a node IP is configured, a dummy "loopback" interface is +automatically created with that IP. + +NOTE: Unlike OSPF and OpenFabric, BGP unnumbered interfaces do not need IP +addresses. Peering is established using IPv6 link-local addresses +automatically. + +NOTE: In an eBGP unnumbered fabric, directly peering nodes must have different +ASNs for BGP sessions to establish. + +[[pvesdn_bgp_evpn]] +Using BGP Fabrics with EVPN +^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +When configuring an EVPN controller, a BGP fabric can be selected as the +underlay instead of manually specifying peer addresses. The default +configuration runs the EVPN overlay (VTEP) sessions as iBGP, using the EVPN +controller's ASN for the router process. The per-node fabric ASN is +automatically applied via `local-as` on the underlay neighbor group. + +This means the EVPN controller ASN and the per-node fabric ASNs should be +different. For example, with three nodes using ASNs 65001, 65002, and 65003 for +the underlay, the EVPN controller could use ASN 65000 for the overlay. + +Alternatively, setting BGP Mode to "external" on the EVPN controller runs the +VTEP sessions as eBGP. The per-node fabric ASN is then used as the local ASN +for the VTEP peer-group as well, so the VTEPs naturally peer with each other +under different ASNs without needing a separate overlay ASN. The EVPN +controller ASN is still used for auto-derived route-target values to keep +them consistent across the fabric. + +NOTE: Using a BGP fabric for an EVPN underlay requires each node to have an +IPv4 address, since EVPN uses it as the VTEP address. + [[pvesdn_config_ipam]] IPAM ---- -- 2.47.3