On Thu, Sep 6, 2012 at 11:11 AM, James B. Byrne <byrnejb at harte-lyne.ca> wrote: > I am still having some difficulty understanding what is going on with > routing on 192.168.x.x. > > I have removed the IP aliases from the gateway eth1 so that it only > responds to aaa.bbb.ccc.1. > > I have changed the netmask on Host B eth1 [192.168.209.43] to > 255.255.0.0 and set its gateway to aaa.bbb.ccc.1; as I have on all of > the guests that have eth1 active. > > The network service on both hosts and guests has been restarted. > > However, when I do a traceroute from Host C [aaa.bbb.ccc.25] to > 192.168.209.43 it still goes directly to the gateway at aaa.bbb.ccc.1 > and thence out to the eth0 i/f on the gateway, where it dies as > before. > > I note that Host C is a xen virtual host (used for some experiments > several years ago but no longer hosting any active guests) and that it > has the following virtual interface: > > 5: virbr0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue > link/ether 00:00:00:00:00:00 brd ff:ff:ff:ff:ff:ff > inet 192.168.122.1/24 brd 192.168.122.255 scope global virbr0 > > This has an address in the same network as 192.168.209.43 but with a > different netmask. This seems to eb the case on the kvm virtual hosts > as well. > > 6: virbr0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue > state UNKNOWN > link/ether 52:54:00:a6:3f:49 brd ff:ff:ff:ff:ff:ff > inet 192.168.122.1/24 brd 192.168.122.255 scope global virbr0 > > So, is this the source of the problem when I try and connect to > 192.168.209.43? Is the netblock 192.168.255.255 constrained to use a > netmask of 255.255.255.0 because of its use by the virtual hosts? > A 'route -n' should show you where any destination will head on the next hop. On host C, what is the line with the smallest matching destination/mask? Likewise, on the gateway host where you think it is being forwarded the wrong way? -- Les Mikesell lesmikesell at gmail.com