Bug 1462955 - [3.4] Node lost connectivity to pod on another node (due to invalid ARP cache)
Summary: [3.4] Node lost connectivity to pod on another node (due to invalid ARP cache)
Keywords:
Status: CLOSED ERRATA
Alias: None
Product: OpenShift Container Platform
Classification: Red Hat
Component: Networking
Version: 3.4.1
Hardware: Unspecified
OS: Linux
urgent
urgent
Target Milestone: ---
: 3.4.z
Assignee: Ben Bennett
QA Contact: Meng Bo
URL:
Whiteboard:
Depends On: 1451854
Blocks: 1462952
TreeView+ depends on / blocked
 
Reported: 2017-06-19 18:24 UTC by Ben Bennett
Modified: 2017-08-28 10:50 UTC (History)
11 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Cause: When an IP address was re-used it would be generated with a random MAC address that would be different from the previous one. Consequence: Any node with an ARP cache that still held the old entry for the IP would not be able to communicate with the node. Fix: Generate the MAC address deterministically from the IP address. Result: A re-used IP address will always have the same MAC address, so the ARP cache can not be out of sync. So the traffic will flow.
Clone Of: 1451854
Environment:
Last Closed: 2017-07-11 10:47:38 UTC
Target Upstream Version:
Embargoed:

Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Github openshift ose pull 792 0 None None None 2017-06-19 18:39:08 UTC
Origin (Github) 14685 0 None None None 2017-06-19 18:24:11 UTC
Red Hat Product Errata RHBA-2017:1640 0 normal SHIPPED_LIVE OpenShift Container Platform 3.5 and 3.4 bug fix update 2017-07-11 14:47:16 UTC

Comment 2 Ben Bennett 2017-06-21 15:53:46 UTC 
OSE PR https://github.com/openshift/ose/pull/792
Comment 3 Hongan Li 2017-06-22 07:17:25 UTC 
verified in atomic-openshift-3.4.1.42-1.git.0.e775fe2.el7.x86_64 and the MAC address generation has been changed, and on other issue found during regression.


>ip address
3: eth0@if15: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 8951 qdisc noqueue state UP 
    link/ether 0a:58:0a:02:04:06 brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet 10.2.4.6/23 scope global eth0

>openflow
 cookie=0x0, duration=8833.941s, table=2, n_packets=1, n_bytes=42, priority=100,arp,in_port=7,arp_spa=10.2.4.6,arp_sha=0a:58:0a:02:04:06 actions=load:0->NXM_NX_REG0[],goto_table:5
Comment 5 errata-xmlrpc 2017-07-11 10:47:38 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, 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-2017:1640
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