DHCP next-server on CISCO2960 LanBase issue [Ter...]

[xavier.le-goff]

Hello, I have CISCO 2960, LANBase last IOS revision: Model SW Version SW Image ----- ---------- ---------- WS-C2960+24TC-L 15.0(2)SE5 C2960-LANBASEK9-M I am configuring DHCP Server Feature with PortBase allocation. Also I have a DHCP client that needs to boot an another tftp server so I have configured the "next-server" command with the IP of that tftp server. I have capture the DHCP/BOOTP frame with wireshark and I can see that on the boot reply frame the Next Server IP address is the Switch IP address instead of the IP configured with the "next-server" command As anyone have an explanation about this ? As anyone have an explanation about this ? Thanks in advance for your support and feedback on the issue. Best Regards, XLG.

[luckymike33]

Hi,

I think you probably need to use dhcp option 150 to be able to point a client device at a tftp server, the next-server command is used to configured multiple dhcp servers in a list, which are then tried one by one.

You may also be able to configure a bootfile on teh dhcp server itself

HTH

Mike

[xavier.le-goff]

Hello Mike,

Thanks for your reply. I think I have found the issue; It is more a DHCP/BOOTP Client issue.

The OS client is RedBoot :

http://ecos.sourceware.org/docs-latest/redboot/redboot-guide.html

And it seems that it OS only support BOOTP, not DHCP. And it seems that with the BOOTP protocol the "Next Server IP" is always the IP address of the BOOTP Server, while in the DHCP protocol the "Next Server IP" could be different.

I have confirmed that with wireshark and another OS Client that support fully DHCP, the switch replies with a "Next server" field with an IP address that it is different from its own IP address.

I need to check if Redboot can support DHCP.

Best regards,

XLG.