Using dhcpcd client to fetch vendor specific options

Mon Mar 13 13:56:44 UTC 2023

Rajeev,

Have a look at the man pages for dhcpcd.  Specifically:
https://man.archlinux.org/man/dhcpcd.conf.5.en and then find "option"
in there.  You should be able to set option 55 I'd think using that
functionality.  Though I've no way to test that theory.

On Mon, Mar 13, 2023 at 9:24 AM rajeev Gaur <rajeev11gaur at gmail.com> wrote:
>
> Hello Darren and all
>
> I searched on the web, I was not able to find any method for setting option 55 or for getting Option 43 items.
> I checked the github queries that community has posted but nothing for vendor options.
> I feel that dhcpcd support is comparatively lesser than dhclient.
> My problem is the project I am working on is using yocto build environment and yocto build environment supports dhcpcd client by default.
> For dhclient probably there will be requirement for cross-compiling the code and then generate binary for the hardware, still will it work or not. But I don't mind giving it a try.
> Any suggestions / hints are welcome.
>
> Thanks
> Rje
>
> On Sun, Mar 12, 2023 at 1:12 AM rajeev Gaur <rajeev11gaur at gmail.com> wrote:
>>
>> Hello Darren and All
>>
>> Thank you for the response.
>> Yes you are correct, I need to use dhcp client to fetch vendor options (option 43) items from DHCP Server.
>> Ok let me check how can I set option 55 Parameter Request List. But I was not able to find it in dhcpcd man pages.
>> Let me search further on net.
>>
>> Thanks
>> Rajeev
>>
>> On Sat, Mar 11, 2023 at 10:15 PM Darren Ankney <darren.ankney at gmail.com> wrote:
>>>
>>> Rje,
>>>
>>> If I understand correctly, you are wanting your DHCP client to fetch
>>> option 43 content from the server.  There should be a way, in dhcpcd,
>>> to modify option 55 (parameter request list) adding the vendor options
>>> (option 43) to the list of requested parameters.  Then the server will
>>> return the option 43 content.
>>>
>>> On Sat, Mar 11, 2023 at 2:29 AM rajeev Gaur <rajeev11gaur at gmail.com> wrote:
>>> >
>>> > Hello Sir
>>> >
>>> > I am working on a project for fetching various different categories of information from dhcp server.
>>> > DHCP Server: ISC DHCP Server 4.4.1
>>> > Client: dhcpcd 9.4.0, Compiled in features: INET ARP ARPing IPv4LL INET6 DHCPv6 AUTH
>>> > Build environment: Yocto
>>> >
>>> > At this point when I am writing this mail, the basic working looks good.
>>> >
>>> > The DHCP server, starts stops restarts well. In logs I can see the DISCOVER / OFFER / REQUEST / ACK all working fine. Lease IP is properly provided to client.
>>> >
>>> > #
>>> >
>>> > # DHCP Server Configuration file.
>>> >
>>> > #   see /usr/share/doc/dhcp*/dhcpd.conf.sample
>>> >
>>> > #
>>> >
>>> >
>>> >
>>> > authoritative;
>>> >
>>> >
>>> >
>>> > option space  Vendor-ONAS-INFO code width 1 length width 1 hash size 5;
>>> >
>>> > option  Vendor-ONAS-INFO.ipadd code 1 = ip-address;
>>> >
>>> > option Vendor-ONAS-INFO.port code 9 = unsigned integer 16;
>>> >
>>> >
>>> >
>>> > subnet 192.168.2.0 netmask 255.255.255.0 {
>>> >
>>> >        range 192.168.2.35  192.168.2.52;
>>> >
>>> >        option routers                   192.168.2.56;
>>> >
>>> >        option subnet-mask               255.255.255.0;
>>> >
>>> >        option domain-name-servers 8.8.8.8;
>>> >
>>> >        default-lease-time 100;
>>> >
>>> >        max-lease-time 100;
>>> >
>>> >        option host-name "OR-SERVER";
>>> >
>>> >        option ntp-servers 138.12.56.111;
>>> >
>>> >        option vendor-class-identifier "Vendor-ONAS";
>>> >
>>> >         vendor-option-space Vendor-ONAS-INFO;
>>> >
>>> >          option Vendor-ONAS-INFO.ipadd 192.168.71.50;
>>> >
>>> >          option Vendor-ONAS-INFO.port 11372;
>>> >
>>> > }
>>> >
>>> >
>>> > On the client side, dhcpcd, I have kept information to allow and deny interfaces, enabled the standard DHCP options for which I am getting values ( except for dhcp_client_identifier).
>>> > When I am performing ifdown and ifup for eth0 I am getting one leased IP from the dhcp server.
>>> >
>>> > #Use the hardware address of the interface for the Client ID
>>> > clientid
>>> > allowinterfaces eth0
>>> > denyinterfaces eth1
>>> >
>>> > option ntp_servers
>>> > option dhcp_server_identifier
>>> > option dhcp_client_identifier (**Not getting this output)
>>> >
>>> > My problem / Query:
>>> > 1) What option to give in dhcpcd.conf to fetch the vendor options that i have declared in dhcpd.conf at the server side.
>>> > 2) Do I need to enable any thing on any side (client or server).
>>> >
>>> > I did not see much documentation for dhcpcd client for vendor options.
>>> > I did saw the dhcpcd.conf man page for vendor information but it shows:
>>> > vendor code ,valueAdd an encapsulated vendor option. code should be between 1 and 254 inclusive. To add a raw vendor string, omit code but keep the comma. Examples. Set the vendor option 01 with an IP address.vendor 01,192.168.0.2Set the vendor option 02 with a hex code.vendor 02,01:02:03:04:05Set the vendor option 03 with an IP address as a string.vendor 03,\"192.168.0.2\"Set un-encapsulated vendor option to hello world.vendor ,"hello world"
>>> >
>>> > But I don't need to add any vendor option I have to fetch it from the server.
>>> >
>>> > I also tried giving vendorclassid so that it can fetch the details provided for the vendor class identifier in the server, but i don't see any output.
>>> >
>>> > I have previously worked with dhclient and i was able to fetch information using that and I also see it has much more documentation online. But i see less documentation for dhcpcd. But this is the only recommended client for Yocto build environment.
>>> >
>>> > Please suggest how can I fetch the vendor options using dhcpcd client.
>>> >
>>> > Thanks
>>> > Rje
>>> > --
>>> > ISC funds the development of this software with paid support subscriptions. Contact us at https://www.isc.org/contact/ for more information.
>>> >
>>> > dhcp-users mailing list
>>> > dhcp-users at lists.isc.org
>>> > https://lists.isc.org/mailman/listinfo/dhcp-users
>>> --
>>> ISC funds the development of this software with paid support subscriptions. Contact us at https://www.isc.org/contact/ for more information.
>>>
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>>> dhcp-users at lists.isc.org
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>
> --
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>
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