Bug 1595412

Summary:	dhcp: router outside client subnet mask no longer works
Product:	Red Hat Enterprise Linux 6	Reporter:	Chris Cheney <ccheney>
Component:	dhcp	Assignee:	Pavel Zhukov <pzhukov>
Status:	CLOSED ERRATA	QA Contact:	Ondrej Mejzlik <omejzlik>
Severity:	urgent	Docs Contact:
Priority:	urgent
Version:	6.10	CC:	dchong, fkrska, jenander, lmanasko, lpol, mkolaja, pzhukov, thozza, toneata, zmarano
Target Milestone:	rc	Keywords:	Patch, Regression
Target Release:	---
Hardware:	All
OS:	All
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:	Previously, due to incorrect handling of classless static routes in the dhclient script, routing was not set properly. As a consequence, network connections on Google Compute Engine machines did not work. This update fixes handling of classless static routes and network connection works as expected.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2018-07-10 17:54:30 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:

Description Chris Cheney 2018-06-26 21:36:55 UTC

Description of problem:

If a client is given a subnet mask where the router is outside of it as of dhclient 4.1.1-60 it no longer works due to the change to fix BZ#1527995.

This appears to be due to the fact it won't run the code unless is_router_reachable is true, which was not the case previously.


diff -Nruab 4.1.1-53/dhclient-script 4.1.1-60/dhclient-script
--- 4.1.1-53/dhclient-script    2018-06-26 14:10:21.882181860 -0500
+++ 4.1.1-60/dhclient-script    2018-06-26 14:10:30.438209325 -0500
@@ -451,6 +451,17 @@
                 fi
                 gateway=${static_routes[$i+1]}

+                # special case 0.0.0.0 to allow static routing for link-local addresses
+                # (including IPv4 multicast) which will not have a next-hop (#769463, #787318)
+                if [ "${gateway}" = "0.0.0.0" ]; then
+                    valid_gateway=0
+                    scope='scope link'
+                else
+                    is_router_reachable ${gateway}
+                    valid_gateway=$?
+                    scope=''
+                fi
+                if [ ${valid_gateway} -eq 0 ]; then
                 metric=''
                 for t in ${route_targets[@]}; do
                     if [ ${t} = ${target} ]; then

Comment 8 Pavel Zhukov 2018-06-27 08:25:34 UTC

Fedora bug: https://bugzilla.redhat.com/show_bug.cgi?id=1102830

Comment 24 errata-xmlrpc 2018-07-10 17:54:30 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, 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-2018:2163