Bug 1462952 - [3.5] Node lost connectivity to pod on another node (due to invalid ARP cache)
Summary: [3.5] 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: ---
: 3.5.z
Assignee: Ben Bennett
QA Contact: Meng Bo
URL:
Whiteboard:
Depends On: 1451854 1462955
Blocks:
TreeView+ depends on / blocked
 
Reported: 2017-06-19 18:18 UTC by Ben Bennett
Modified: 2017-07-18 06:51 UTC (History)
10 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 791 0 None None None 2017-06-19 18:33:58 UTC
Origin (Github) 14685 0 None None None 2017-06-19 18:18:55 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 Hongan Li 2017-06-23 02:19:04 UTC 
verified in atomic-openshift-3.5.5.28-1.git.0.5eb85e0.el7.x86_64, the pod MAC address generation has been changed and no other issue found.

  3: eth0@if15: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 8951 qdisc noqueue state UP 
    link/ether 0a:58:0a:02:02:09 brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet 10.2.2.9/23 scope global eth0
Comment 4 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
Note You need to log in before you can comment on or make changes to this bug.