Bug 2211240

Summary:	IPv6 LLA is stored to mac_bindings table on NA
Product:	Red Hat Enterprise Linux Fast Datapath	Reporter:	Jakub Libosvar <jlibosva>
Component:	ovn-2021	Assignee:	Ales Musil <amusil>
Status:	CLOSED ERRATA	QA Contact:	Jianlin Shi <jishi>
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	FDP 21.G	CC:	amusil, bcafarel, ctrautma, dalvarez, ihrachys, jiji, mmichels, shtiwari
Target Milestone:	---
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:	ovn-2021-21.12.0-134.el8fdp	Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2023-07-06 20:05:30 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:
Bug Blocks:	2203848

Description Jakub Libosvar 2023-05-30 22:30:10 UTC

Description of problem:
When the logical router has always_learn_from_arp_request="false" option set, it still learns MAC/IP when an instance sends out Neighbor Advertisement using its IPv6 LLA. With plenty of instances in a network connected to the router, it leads to huge growth of mac binding table.

Version-Release number of selected component (if applicable):
ovn-2021-21.12.0-116.el8fdp.x86_64

How reproducible:
Always

Steps to Reproduce:
1. Have a router connected to a network
2. Spawn a VM on the network
3. Send NA packet with its LLA address

Actual results:
mac binding is created

Expected results:
OVN can calculate LLAs of known ports by its own and avoid creating unnecessary entries


Additional info:
The entry is created even if the LLA is configured in LSP addresses and port security columns.

I used following script to send the NA from within the guest instance.

from scapy.all import *

# Craft the ND broadcast packet
na_packet = Ether(dst="ff:ff:ff:ff:ff:ff")/IPv6(dst="fe80::1")/ICMPv6ND_NA(tgt="fe80::f816:3eff:fe55:a747")

# Send the packet
sendp(na_packet, iface="eth0")

Comment 1 Ihar Hrachyshka 2023-05-31 00:39:08 UTC

Fix in u/s: https://patchwork.ozlabs.org/project/ovn/patch/20230530095953.170545-1-amusil@redhat.com/

Comment 5 OVN Bot 2023-06-08 17:45:23 UTC

ovn-2021 fast-datapath-rhel-9 clone created at https://bugzilla.redhat.com/show_bug.cgi?id=2213612

Comment 11 Jianlin Shi 2023-07-03 09:15:36 UTC

Tested with script in https://bugzilla.redhat.com/show_bug.cgi?id=2213612#c6
reproduced on ovn-2021-21.12.0-103.el8:

+ sleep 5                                                                                             
+ ip netns exec ls1p1 python3 test.py                                                                 
.                                                                                                     
Sent 1 packets.                                                                                       
+ ovn-sbctl list mac_binding                                                                          
_uuid               : 9278324e-9960-45de-bbaf-2d64c646d13c                                            
datapath            : ea7777ea-e196-4bd0-9f7c-835468c34545                                            
ip                  : "fe80::f816:3eff:fe55:a747"                                                     
logical_port        : lr1-ls1                                                                         
mac                 : "00:00:00:01:01:02"                                                             
[root@sweetpig-8 bz2213612]# rpm -qa | grep -E "openvswitch2.17|ovn-2021"                             
ovn-2021-central-21.12.0-103.el8fdp.x86_64                                                            
ovn-2021-21.12.0-103.el8fdp.x86_64                                                                    
ovn-2021-host-21.12.0-103.el8fdp.x86_64                                                               
openvswitch2.17-2.17.0-106.el8fdp.x86_64

Verified on ovn-2021-21.12.0-134.el8:

+ ip netns exec ls2p1 ip -6 route add default via 2002::a
+ sleep 5
+ ip netns exec ls1p1 python3 test.py                                                                 
.
Sent 1 packets.
+ ovn-sbctl list mac_binding
[root@sweetpig-8 bz2213612]# rpm -qa | grep -E "openvswitch2.17|ovn-2021"                             
ovn-2021-host-21.12.0-134.el8fdp.x86_64
ovn-2021-central-21.12.0-134.el8fdp.x86_64
openvswitch2.17-2.17.0-106.el8fdp.x86_64
ovn-2021-21.12.0-134.el8fdp.x86_64

Comment 13 errata-xmlrpc 2023-07-06 20:05:30 UTC

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory (ovn-2021 bug fix and enhancement update), and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHBA-2023:3995