Red Hat Bugzilla – Bug 434625
NetworkManager dhcp setup not robust enough
Last modified: 2013-02-19 00:21:53 EST
Description of problem:
Many ill-configured dhcp server e.g. in hotel-room access points provide gateway
ip addresses outside of the local net or simply wrong netmasks (such as
255.255.255.255). In that case a RHEL client connecting using NetworkManager
will not set up any routes and thus will not be able to connect to the network,
although an explicit and correct ip address for the router was given and it
actually would be reachable with a host-route.
Version-Release number of selected component (if applicable):
Set up a dhcp server with a wrong netmask for the local network, such as
255.255.255.255, so that the default gateway's ip address is outside of the
network assigned to the local system.
Steps to Reproduce:
1. Connect to the network with the so mis-configured dhcp-server
2. run ip route
No routes are set
A host route to the gateway should be set regardless of the mis-configuration.
/sbin/dhclient-script has provisions for this case and correctly sets a
host-route to the gateway if run manually in the very same configuration.
The impact of this problem is that normal users running RHEL without technical
expertise often can not connect to the Internet in hotels, etc. Windows for
example is more robust and handles the situation gracefully.
So if you want to patch it, what I told you was for 0.7. For RHEL5, you'll
probably want to look at src/NetworkManagerSystem.c,
This request was evaluated by Red Hat Product Management for inclusion in a Red
Hat Enterprise Linux maintenance release. Product Management has requested
further review of this request by Red Hat Engineering, for potential
inclusion in a Red Hat Enterprise Linux Update release for currently deployed
products. This request is not yet committed for inclusion in an Update
grr, not actually modified yet.
Still not sure what's different with the kernels, and its too late in the cycle to fix. Moving to 5.4.
dhcpd isn't letting me configure it in this way. Can we get an example configuration for testing?
Looks like this is actually being punted to 5.5.
This request was evaluated by Red Hat Product Management for
inclusion in the current release of Red Hat Enterprise Linux.
Because the affected component is not scheduled to be updated in the
current release, Red Hat is unfortunately unable to address this
request at this time. Red Hat invites you to ask your support
representative to propose this request, if appropriate and relevant,
in the next release of Red Hat Enterprise Linux.
Not going to get fixed on RHEL5, but it works on RHEL6 and Fedora.