Bug 1302509

Summary:	[Docs] [RFE] Gateway setting for non-management networks lacks explanation in Administration Guide.
Product:	Red Hat Enterprise Virtualization Manager	Reporter:	Germano Veit Michel <gveitmic>
Component:	Documentation	Assignee:	Byron Gravenorst <bgraveno>
Status:	CLOSED CURRENTRELEASE	QA Contact:	Megan Lewis <melewis>
Severity:	medium	Docs Contact:
Priority:	unspecified
Version:	3.5.7	CC:	alkaplan, amuller, danken, gklein, gveitmic, lbopf, lsurette, rbalakri, srevivo, ylavi
Target Milestone:	ovirt-3.6.8	Keywords:	FutureFeature
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Enhancement
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2016-08-01 03:20:12 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	Docs	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description Germano Veit Michel 2016-01-28 02:31:36 UTC

Description of problem:

In RHEV-M GUI, if we fill the Gateway setting the management network this address is used for the default route.

However, if we fill it for non-management networks, we are actually setting up source based routing by using special routing tables and ip rules to instruct the kernel to look at specific tables in the FIB for packets which have specific source-IP/interfaces. See: http://www.ovirt.org/Features/Multiple_Gateways

Our documentation in https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Virtualization/3.5/html/Administration_Guide/sect-Hosts_and_Networking.html (section 7.6.2. Editing Host Network Interfaces and Assigning Logical Networks to Hosts) does not mention this important detail. 

So people fill the gateway option for non management networks and expect that gateway to be the default route for the Host. But it is not since it's only valid for forwarding (not in use) or reply packets arriving from that Network (some conntrack magic here I suppose).

So I suggest we put a note in there to link some other part of the documentation or to explain these differences.

I haven't confirmed this in 3.6 but I suppose it's the same.

Cheers,
Germano

Comment 2 Andrew Dahms 2016-02-02 12:11:45 UTC

*** Bug 1302508 has been marked as a duplicate of this bug. ***

Comment 3 Lucy Bopf 2016-05-03 06:24:22 UTC

Assigning to Byron for review.

Comment 6 Byron Gravenorst 2016-06-13 00:59:28 UTC

Hi Assaf,

I'm currently adding some documentation for this feature, however I'm hoping someone could confirm that this is still valid in RHEV 4.0.

Hoping you could help with this, or perhaps forward this to someone who can?

Kind regards,

Comment 7 Dan Kenigsberg 2016-07-19 12:11:26 UTC

Yes, this is valid for 4.0, and not expected to change in the near future.

Comment 10 Byron Gravenorst 2016-08-01 03:20:12 UTC

This content has been published and is available at:

- https://access.redhat.com/documentation/en/red-hat-virtualization/4.0-beta/single/administration-guide/#sect-Hosts_and_Networking

And

- https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Virtualization/3.6/html-single/Administration_Guide/index.html#Editing_host_network_interfaces