Remove the unspecified gateway from linux routing table

[Patrick Trapp]

Perhaps I am not completely awake yet, but don't you have to have the default gateway in place to have network communication? That is, doesn't it have to precede the DHCP process?

It sounds to me like you just need to make the default route persistent so it will survive a reboot. How that is done depends on the flavor of Linux you are running.

Patrick



On Feb 17, 2015, at 4:43 AM, Eugène Ngontang <sympavali at gmail.com<mailto:sympavali at gmail.com>> wrote:

Hi all,

I've a remote linux machine whose the routing table is :

    [root at hostname]# route -n
    Kernel IP routing table
    Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
    0.0.0.0         0.0.0.0         0.0.0.0         U     0      0        0 eth0
    10.10.10.16    0.0.0.0         255.255.255.240 U     0      0        0 eth0
    169.254.0.0     0.0.0.0         255.255.0.0     U     1002   0        0 eth0

The default gateway I should use is  10.10.10.17, and should be given by a linux dhcp server. So to be able to connect to the system I call someone on the site ask him to add the route manually (**route add default gw 10.10.10.17**).
When the route has been added I can now connect to the system. And once connected when I check the routing table again I have this :

    [root at hostname]# route -n
    Kernel IP routing table
    Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
    0.0.0.0         10.10.10.17    0.0.0.0         UG    0      0        0 eth0 (UG flag means it's up and is the gateway)
    0.0.0.0         0.0.0.0         0.0.0.0         U     0      0        0 eth0
    10.10.10.16    0.0.0.0         255.255.255.240 U     0      0        0 eth0
    169.254.0.0     0.0.0.0         255.255.0.0     U     1002   0        0 eth0

And when I restart the system, it boots without the right default gateway, and I'm obliged to call again to set the route manually. The dhclient lease file has the good **"option routers"** taken from the dhcp server.

Now I'm trying to remove the unspecified route from the routing table but each time I try I'm disconnected from the machine.

I've tried these different ways  :

    route del -net 0.0.0.0 netmask 0.0.0.0 metric 0

    route del default gw 0.0.0.0

    route del -net 0.0.0.0 gw 0.0.0.0

The three attempts disconected me from the server, and the guy at the other side tells me that each time I try to remove the route the default route becomes a star (**default ***). I'm obliged to let him add the route again mannualy, and when I'm connected, and I restart the network I lose the connection again.

So my questions are :
1) Why does this unspecified default route come back every time?
2) How can I (what's the way to) remove it without spoiling the routing table (losing the good  default gateway).

Thanks.

Regards,
Eugène NG



--
ngonta_e at epitech.net<mailto:ngonta_e at epitech.net>
sympavali at gmail.com<mailto:sympavali at gmail.com>
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