Red Hat Bugzilla – Bug 146277
dhclient-script fails add route to gateway before adding the default route
Last modified: 2007-11-30 17:10:59 EST
From Bugzilla Helper: User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.5) Gecko/20050126 Firefox/1.0 Description of problem: When the host is happen to be on DHCP and the default gateway(router) IP doesn't belong to the local network (ex: host address is 192.168.4.127 but gateway address is 202.142.94.106) dhclient-script tries to add default route to gate which fails because the gateway itself is not reacheable. Only entry in routing table will the for hosts local network. The dhclient-script ideally add the route to the gateway first then add the default route if the gateway IP not as the local network IP. Note: My machine is on a local lan on DHCP. Version-Release number of selected component (if applicable): dhclient-3.0.1-30_FC3 How reproducible: Always Steps to Reproduce: 1.Get to the DHCP setuation as described 2.run dhclient <interface> 3. Actual Results: dhclient says Network not reachable and routing table only contains one entry to local network. Expected Results: Expected routing table is setup properly with default gateway. Additional info:
Created attachment 110259 [details] Patched dhclient-script: Simple fix adding host route to gw before adding default route Not sure it is a correct fix or not it works for me.
Your DHCP server is really not meant to be supplying you with a gateway router that is not on your configured subnet . This only works in your case because you are evidently on the same physical LAN as your router and your host sees the router's ARP entry . The operator of your DHCP server and router should be configuring the router with secondary IP addresses for each separate subnet served by the DHCP server, and giving out those secondary IPs that are on the lease subnet as the 'router' DHCP option for each lease . Also we don't want to add a host route for EVERY gateway, only for those not on the interface subnet . A better fix would be as follows: IF the gateway to be configured is not on interface subnet: IF an "ARP ping" succeeds for the gateway: add host route for gateway ELSE emit helpful log message and do not configure interface ENDIF ENDIF configure default gateway We also need to remember to delete the host route when an interface is reconfigured . I'll implement these changes in the next dhcp version for FC3 (dhcp-3.0.1-32_FC3).
This is now done in dhcp-3.0.1-31_FC3, which can be downloaded from: http://people.redhat.com/~jvdias/DHCP/FC3/3.0.1-31_FC3 I've tested it with a DHCP server that supplies a router not on the subnet of the DHCP supplied IP address, and it works fine. Please test and let me know how it works for you and I'll push it to fc3-updates. Thanks!
I have updated to dhcp-3.0.1-31_FC3 and tested it, it works great thanks.
update package is published