classless routes

Wed Feb 21 14:31:11 UTC 2007

Hi.
Answering your suggestions:

1 - I'm not sure about that. I think I should be able to route as I want.
Manually I delete the direct route and left only the route through
192.168.0.1 and it worked as expected.

2. Yes. You're right. That was how I did it yesterday (I understood RFC as
you say). But someone in this list suggested me to put the complete network
(although this is not correspond with RFC). I tried in this way this
morning, and this is why on my mail (neraly a copy and paste) it appeared in
such form. But I tried yesterday with the RFC recommendation

Thx,

ENriq

2007/2/21, Tim Peiffer <peiffer at umn.edu>:
>
> I see two issues to comment on.  1 - Isn't your static route competing
> with your interface route?  You can't route to something that is within
> your same layer3 address space.  2 - Are you misreading the RFCs?
> Option 249 specifies that the route as 8 octets.  The first 4 octets
> are  the bitlength shift left 3 octets imposed over the network right
> sifted 1 octet ((bitlength << 24) OR (network > 8).  The second 4 octets
> are the destination address on the same network to forward to.
>
> Ref: http://www.ietf.org/rfc/rfc3442.txt
> Pay attention to page 3 where it specifies how the destination
> descriptors are to be encoded.
> >    The following table contains some examples of how various subnet
> >    number/mask combinations can be encoded:
> >
> >    Subnet number   Subnet mask      Destination descriptor
> >    0               0                0
> >    10.0.0.0        255.0.0.0        8.10
> >    10.0.0.0        255.255.255.0    24.10.0.0
> >    10.17.0.0       255.255.0.0      16.10.17
> >    10.27.129.0     255.255.255.0    24.10.27.129
> >    10.229.0.128    255.255.255.128  25.10.229.0.128
> >    10.198.122.47   255.255.255.255  32.10.198.122.47
> With the above in mind, shouldn't you encode the route as:
>
> option ca-static-routes 24,192,168,0, 192,168,0,1;
>
> ??
>
> Tim Peiffer
> Networking and Telecommunications Services
> University of Minnesota
>
>
> Enrique de Guindos Carretero wrote:
> > Hello Eric.
> > Thanks for your quick answer.
> >
> > Unfortunately, my dhcp still does not work as I want with Linux clients.
> > Now, my config file is the next:
> >
> >
> -----------------------------------------------------------------------------------------------
> >
> > ddns-update-style none;
> > authoritative;
> >
> > default-lease-time              3600;           # 1 hora
> > max-lease-time                  14400;
> >
> > option ca-static-routes code 121  = array of unsigned integer 8;
> >
> > <several options for domain, dns server, etc...>
> >
> > option  broadcast-address       192.168.0.255;
> > option  routers                        192.168.0.1;
> > option  subnet-mask               255.255.255.0;
> >
> > subnet  192.168.0.0  netmask 255.255.255.0
> > {
> >         pool
> >         {
> >                 range   192.168.0.15    192.168.0.50;
> >                 option ca-static-routes 24, 192,168,0,0, 192,168,0,1;
> >         }
> > }
> > ...
> >
> ---------------------------------------------------------------------------------------------------
> >
> > But as soon as a Linux dhcp client boots, it has the normal route table,
> > same as if I do not put the code 121 option:
> >
> > linux_client#> route
> >
> > Destination   Gateway      Genmask        Flags   Metric   Ref   Use
> Iface
> > 192.168.0.0   *                 255.255.255.0 U         0          0
> > 0       eth0
> > default          192.168.0.1  0.0.0.0           UG       0          0
> > 0       eth0
> >
> > And I think I should expect something like
> >
> > Destination   Gateway   ...
> > 192.168.0.0  192.168.0.1
> >
> > The above is what I observe on Windows Clients if I add an option for
> code
> > 249 instead (or together with) of code 121.
> >
> > Do you see anything wrong on my configuration?
> >
> > Just to let you know, I'm using OpenSuSE 10.2
> >
> > Thanks a lot in advance,
> >
> > Enrique
> >
> > 2007/2/20, Eric Helm <helmwork at ruraltel.net>:
> >
> >> Enrique de Guindos Carretero wrote:
> >>
> >>> Hello.
> >>> I'm new to dhcp and I'm having a problem.
> >>>
> >>> I have read RFC 3442 concerning classless routes sent to the dhcp
> >>>
> >> clients.
> >>
> >>> As I saw, Windows clients are using code 249 while the standard one is
> >>>
> >> 121.
> >>
> >>> On Windows clients I have no problems. But I have troubles on Linux
> >>>
> >> ones.
> >>
> >>> On my dhcpd.conf I have:
> >>>
> >>> option  ca-static-routes code 121 = string;
> >>> option  ca-static-routes 18:C0:A8:00:C0:A8:00:01;
> >>>
> >>> In order of having  192.168.0.0/24 routed through 192.168.0.1 router.
> >>> Changing the code with 249 works for windows clients. But with code
> 121,
> >>>
> >> my
> >>
> >>> Linux clients are receiving nothing and they have not the static route
> >>> configured.
> >>>
> >>> Is it there any solution?
> >>>
> >>>
> >> For my linux hosts, this config works to supply option 121:
> >> option classless-routes code 121 = array of unsigned integer 8;
> >>
> >> subnet 192.168.0.0 netmask 255.255.255.0
> >> {
> >>        pool
> >>        {
> >>                range 192.168.0.2 192.168.0.254
> >>                option classless-routes 24, 192,168,0,0,  192,168,0,1;
> >>        }
> >> }
> >>
> >> /Eric
> >>
> >>
> >>
> >
> >
> >
>
>
>