From cb6e090a90d283f3e9e31926f255e385a34bd721 Mon Sep 17 00:00:00 2001 From: Donatas Abraitis Date: Tue, 17 Jan 2023 18:15:50 +0200 Subject: [PATCH] Revert "doc: Add documentation for BGP ORR support" This reverts commit 2b55ff400f6d6fcb471310286f07843bfc5e0b37. --- doc/user/bgp.rst | 317 --------------------------------------------- doc/user/ospfd.rst | 4 - 2 files changed, 321 deletions(-) diff --git a/doc/user/bgp.rst b/doc/user/bgp.rst index 77b4d35afb..27e1744ef5 100644 --- a/doc/user/bgp.rst +++ b/doc/user/bgp.rst @@ -3566,319 +3566,6 @@ When default route is not present in R2'2 BGP table, 10.139.224.0/20 and 192.0.2 Total number of prefixes 3 Router2# -.. _bgp-optimal-route-reflection: - -BGP Optimal Route Reflection ----------------------------- -BGP Route Reflectors (RRs) are used to improve network scalability by reducing -or eliminating the need for a full-mesh of IBGP sessions. - -When a BGP RR receives multiple paths for the same IP prefix, it typically -selects a single best path to send for all its clients. -If the RR has multiple nearly-equal best paths and the tie-break is determined -by the next-hop cost, the RR advertises the path based on its view of next-hop -costs, which leads to a non-optimal routing. -The advertised route may differ from the path that a client would select -if it had the visibility of the same set of candidate paths and used -its own view of next-hop costs. - -Non-optimal advertisements by the RR can be a problem in hot-potato routing. -Hot-potato routing aims to hand off traffic to the next AS using the closest -possible exit point from the local AS. -In this context, the closest exit point implies minimum IGP cost to -reach the BGP next-hop. - -The BGP Optimal Route Reflection allows the RR to choose and send a different -best path to a different or a set of RR clients. - -A link-state protocol is required. It can be OSPF or IS-IS. -Current implementation of BGP ORR is based on the IGP cost to the BGP next hop, -and not based on some configured policy. - -RR runs Shortest Path First (SPF) calculation with the selected -router as the root of the tree and calculates the cost to every other router. - -This special SPF calculation with another router as the root, is referred to as -a Reverse SPF (rSPF). This can only be done if the RR learns all the BGP paths -from all the BGP border routers. - -There could be as many rSPFs run as there are RR clients. -This will increase the CPU load somewhat on the RR. - -Current implementation allows up to three root nodes for the rSPF calculation. -There is no need to configure each RR client as a root and run rSPF. -Current implementation allows to configure three, the primary, the secondary, -and the tertiary root, per set of RR clients, for redundancy purposes. -For the BGP ORR feature to apply to any RR client, that RR client must be -configured to be part of an ORR policy group. - -The BGP ORR feature is enabled per address family. - -The minimal configuration needed: - -1. ORR needs to be enabled for specific groups of BGP neighbors. -2. For each group of BGP neighbors, at least one root needs to be configured. - Optionally, a secondary and tertiary root can be configured. -3. For OSPF, the root routers(RR clients) need additional configuration - to make BGP ORR work. - i.e. The MPLS TE configuration on the root router needs to have the minimal - configuration for MPLS TE enabled so that OSPF advertises the MPLS TE - router ID in an opaque-area LSA (type 10). - Once the RR has an opaque-area LSA with the MPLS TE router-ID matching the - configured root router address, rSPF can run and BGP on the RR can - advertise the optimal route. - -.. clicmd:: neighbor A.B.C.D optimal-route-reflection NAME - - This command allows the neighbor to be part of the ORR group. - -.. clicmd:: optimal-route-reflection orr-1 A.B.C.D [A.B.C.D] [A.B.C.D] - - This command creates an ORR group with a mandatory primary root - and optional secondary and/or tertiary roots. - When primary is reachable it will be the active root. - when primary goes down, secondary followed by tertiary takes over - the active root's role. - Always rSPF calculation runs active root as the root. - Which means the RR advertises the path based on active root's - view of next-hop costs. - -Sample Configuration -^^^^^^^^^^^^^^^^^^^^ - -Sample configuration on Route Reflector - -.. code-block:: frr - - ! - debug ospf 8 orr - debug bgp optimal-route-reflection - ! - interface enp0s8 - ip address 10.10.68.8/24 - ip ospf 8 area 0 - exit - ! - interface lo - ip address 10.100.1.8/32 - ip ospf 8 area 0 - exit - ! - router bgp 1 - neighbor 10.100.1.1 remote-as 1 - neighbor 10.100.1.1 update-source lo - neighbor 10.100.1.2 remote-as 1 - neighbor 10.100.1.2 update-source lo - neighbor 10.100.1.3 remote-as 1 - neighbor 10.100.1.3 update-source lo - neighbor 10.100.1.4 remote-as 1 - neighbor 10.100.1.4 update-source lo - ! - address-family ipv4 unicast - neighbor 10.100.1.1 route-reflector-client - neighbor 10.100.1.1 optimal-route-reflection orr-1 - neighbor 10.100.1.2 route-reflector-client - neighbor 10.100.1.2 optimal-route-reflection orr-1 - neighbor 10.100.1.3 route-reflector-client - neighbor 10.100.1.3 optimal-route-reflection orr-1 - neighbor 10.100.1.4 route-reflector-client - neighbor 10.100.1.4 optimal-route-reflection orr-1 - optimal-route-reflection orr-1 10.100.1.4 10.100.1.3 10.100.1.1 - exit-address-family - exit - ! - router ospf 8 - ospf router-id 8.8.8.8 - area 0 authentication - capability opaque - exit - ! - end - -Sample configuration on RR clients - -.. code-block:: frr - - interface enp0s8 - ip address 10.10.34.4/24 - ip ospf 4 area 0 - link-params - enable - exit-link-params - exit - ! - interface enp0s9 - ip address 10.10.74.4/24 - ip ospf 4 area 0 - link-params - enable - exit-link-params - exit - ! - interface lo - ip address 10.100.1.4/32 - ip ospf 4 area 0 - exit - ! - router bgp 1 - neighbor 10.100.1.8 remote-as 1 - neighbor 10.100.1.8 update-source lo - ! - address-family ipv4 unicast - neighbor 10.100.1.8 soft-reconfiguration inbound - exit-address-family - exit - ! - router ospf 4 - ospf router-id 4.4.4.4 - area 0 authentication - capability opaque - mpls-te on - mpls-te router-address 10.100.1.4 - mpls-te inter-as area 0.0.0.0 - mpls-te export - exit - ! - end - -Sample Output -^^^^^^^^^^^^^ - -When Optimal Route Reflection is not enabled on RR, it sends 10.100.1.1 as the best path to its clients. - -.. code-block:: frr - - Router-RR# show ip bgp neighbors 10.100.1.4 - - !--- Output suppressed. - - For address family: IPv4 Unicast - Update group 2, subgroup 2 - Packet Queue length 0 - Route-Reflector Client - Community attribute sent to this neighbor(all) - 0 accepted prefixes - - !--- Output suppressed. - - Router-RR# - Router-RR# show ip bgp - BGP table version is 3, local router ID is 10.100.1.8, vrf id 0 - Default local pref 100, local AS 1 - Status codes: s suppressed, d damped, h history, * valid, > best, = multipath, - i internal, r RIB-failure, S Stale, R Removed - Nexthop codes: @NNN nexthop's vrf id, < announce-nh-self - Origin codes: i - IGP, e - EGP, ? - incomplete - RPKI validation codes: V valid, I invalid, N Not found - - Network Next Hop Metric LocPrf Weight Path - * i203.0.113.0/24 10.100.1.2 0 100 0 i - *>i 10.100.1.1 0 100 0 i - *=i 10.100.1.3 0 100 0 i - - Displayed 1 routes and 3 total paths - Router-RR# - - Router-PE4# show ip bgp - BGP table version is 5, local router ID is 10.100.1.4, vrf id 0 - Default local pref 100, local AS 1 - Status codes: s suppressed, d damped, h history, * valid, > best, = multipath, - i internal, r RIB-failure, S Stale, R Removed - Nexthop codes: @NNN nexthop's vrf id, < announce-nh-self - Origin codes: i - IGP, e - EGP, ? - incomplete - RPKI validation codes: V valid, I invalid, N Not found - - Network Next Hop Metric LocPrf Weight Path - *>i203.0.113.0/24 10.100.1.1 0 100 0 i - - Displayed 1 routes and 1 total paths - Router-PE4# - -When Optimal Route Reflection is enabled on RR, it sends 10.100.1.3 as the best path to its clients. - -.. code-block:: frr - - Router-RR# show ip bgp neighbors 10.100.1.4 - - !--- Output suppressed. - - For address family: IPv4 Unicast - Update group 1, subgroup 1 - Packet Queue length 0 - Route-Reflector Client - ORR group (configured) : orr-1 - Community attribute sent to this neighbor(all) - 0 accepted prefixes - - !--- Output suppressed. - - Router-RR# - Router-RR# show ip bgp - BGP table version is 1, local router ID is 10.100.1.8, vrf id 0 - Default local pref 100, local AS 1 - Status codes: s suppressed, d damped, h history, * valid, > best, = multipath, - i internal, r RIB-failure, S Stale, R Removed - Nexthop codes: @NNN nexthop's vrf id, < announce-nh-self - Origin codes: i - IGP, e - EGP, ? - incomplete - RPKI validation codes: V valid, I invalid, N Not found - - Network Next Hop Metric LocPrf Weight Path - * i203.0.113.0/24 10.100.1.2 0 100 0 i - *>i 10.100.1.3 0 100 0 i - * i 10.100.1.1 0 100 0 i - - Displayed 1 routes and 3 total paths - Router-RR# - - Router-RR# show ip bgp optimal-route-reflection - - ORR group: orr-1, IPv4 Unicast - Configured root: primary: 10.100.1.4(Router-PE4), secondary: 10.100.1.3(Router-PE3), tertiary: 10.100.1.1(Router-PE1) - Active Root: 10.100.1.4(Router-PE4) - - RR Clients mapped: - 10.100.1.1 - 10.100.1.2 - 10.100.1.3 - 10.100.1.4 - - Number of mapping entries: 4 - - Prefix Cost - 10.10.34.0/24 100 - 10.10.61.0/24 300 - 10.10.63.0/24 200 - 10.10.67.0/24 200 - 10.10.68.0/24 300 - 10.10.72.0/24 200 - 10.10.74.0/24 100 - 10.100.1.1/32 300 - 10.100.1.2/32 200 - 10.100.1.3/32 100 - 10.100.1.4/32 0 - 10.100.1.6/32 200 - 10.100.1.7/32 100 - 10.100.1.8/32 300 - - Number of mapping entries: 14 - - Router-RR# - - Router-PE4# show ip bgp - BGP table version is 3, local router ID is 10.100.1.4, vrf id 0 - Default local pref 100, local AS 1 - Status codes: s suppressed, d damped, h history, * valid, > best, = multipath, - i internal, r RIB-failure, S Stale, R Removed - Nexthop codes: @NNN nexthop's vrf id, < announce-nh-self - Origin codes: i - IGP, e - EGP, ? - incomplete - RPKI validation codes: V valid, I invalid, N Not found - - Network Next Hop Metric LocPrf Weight Path - *>i203.0.113.0/24 10.100.1.3 0 100 0 i - - Displayed 1 routes and 1 total paths - Router-PE4# - .. _bgp-debugging: Debugging @@ -3944,10 +3631,6 @@ Debugging Enable or disable debugging of communications between *bgpd* and *zebra*. -.. clicmd:: debug bgp optimal-route-reflection - - Enable or disable debugging of BGP Optimal Route Reflection. - Dumping Messages and Routing Tables ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ diff --git a/doc/user/ospfd.rst b/doc/user/ospfd.rst index 90b5b883f9..b69230b99d 100644 --- a/doc/user/ospfd.rst +++ b/doc/user/ospfd.rst @@ -1145,10 +1145,6 @@ Debugging OSPF .. clicmd:: show debugging ospf -.. clicmd:: debug ospf orr - - Enable or disable debugging of BGP Optimal Route Reflection. - Sample Configuration ==================== -- 2.39.5