Remove the unspecified gateway from linux routing table

[Rudy Zijlstra]

Hi Patrick,

I would suggist to find a strong cup of coffee ;)

DHCP is designed to work with no IP routing  in place at all. Please 
consider that DHCP provides the computer with the IP address it is to 
use. Any gateway is dependent on that IP address and CANNOT be assigned 
before the IP address is known.

The correct question is indeed posed by the OP, which is why the gateway 
is not applied from the DHCP response.

Some questions:
- which distribution is this?
- is dhcp provided by the a package from the distribution, or is it hand 
compiled?
- which release of dhclient/dhcp is in use?
- dhclient typically calls a script to set the values. Is this script 
correct and in place?

Cheers



Rudy

On 17-02-15 11:59, Patrick Trapp wrote:
> 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>
>> ------------------------------------------------------------
>> /*Aux hommes il faut un chef, et au*//* chef il faut des hommes!
>> L'habit ne fait pas le moine, mais lorsqu'on te voit on te juge!
>> */
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