[U-Boot-Users] Duplicate IP address check
Due to a mis-configuration of our DHCP server there was an overlapping range of DHCP assigned IP address and units configured to have IP addresses statically assigned. I was surprised to find that UBOOT did not complain of a duplicate IP address while trying to boot via the network. Looking through the source I cannot see any code to perform the typical ARP for yourself check that I have seen before. Could someone please tell me if I have overlooked something or is this feature missing?
Daniel Batryn Shoretel Inc. 960 Stewart Sunnyvale, CA 94085 Phone: (408) 331-3575 Fax: (408) 331-3333
Hi Dan,
Dan Batryn wrote:
Due to a mis-configuration of our DHCP server there was an overlapping range of DHCP assigned IP address and units configured to have IP addresses statically assigned. I was surprised to find that UBOOT did not complain of a duplicate IP address while trying to boot via the network. Looking through the source I cannot see any code to perform the typical ARP for yourself check that I have seen before. Could someone please tell me if I have overlooked something or is this feature missing?
There is no explicit check for duplicate IP assignment. U-boot's networking code is intentionally minimalist and thus lacks many such features. Feel free to provide a patch and a convincing argument of why it's needed.
regards, Ben
Ben Warren wrote:
Hi Dan,
Dan Batryn wrote:
Due to a mis-configuration of our DHCP server there was an overlapping range of DHCP assigned IP address and units configured to have IP addresses statically assigned. I was surprised to find that UBOOT did not complain of a duplicate IP address while trying to boot via the network. Looking through the source I cannot see any code to perform the typical ARP for yourself check that I have seen before. Could someone please tell me if I have overlooked something or is this feature missing?
There is no explicit check for duplicate IP assignment. U-boot's networking code is intentionally minimalist and thus lacks many such features. Feel free to provide a patch and a convincing argument of why it's needed.
regards, Ben
Ditto on the patch.
WRT the convincing argument, I think the bar would be *really* low on this one. :-) I would consider a convincing argument to be "The nearly universal convention of performing an ARP to verify that the DHCP-assigned IP address is unused is missing."
Best regards, gvb
gvb.uboot wrote:
Ben Warren wrote:
Hi Dan,
Dan Batryn wrote:
Due to a mis-configuration of our DHCP server there was an overlapping range of DHCP assigned IP address and units configured to have IP addresses statically assigned. I was surprised to find that UBOOT did not complain of a duplicate IP address while trying to boot via the network. Looking through the source I cannot see any code to perform the typical ARP for yourself check that I have seen before. Could someone please tell me if I have overlooked something or is this feature missing?
There is no explicit check for duplicate IP assignment. U-boot's networking code is intentionally minimalist and thus lacks many such features. Feel free to provide a patch and a convincing argument of why it's needed.
regards, Ben
Ditto on the patch.
WRT the convincing argument, I think the bar would be *really* low on this one. :-) I would consider a convincing argument to be "The nearly universal convention of performing an ARP to verify that the DHCP-assigned IP address is unused is missing."
Sure, this is a no-brainer. But, it shouldn't be limited to DHCP since having a dynamic address trouncing a static one is only one trouble scenario. Who knows, there may be people out there who object to the extra milliseconds that this ARP will add to boot time (not me).
regards, Ben
Ben Warren wrote:
gvb.uboot wrote:
Ben Warren wrote:
Hi Dan,
Dan Batryn wrote:
Due to a mis-configuration of our DHCP server there was an overlapping range of DHCP assigned IP address and units configured to have IP addresses statically assigned. I was surprised to find that UBOOT did not complain of a duplicate IP address while trying to boot via the network. Looking through the source I cannot see any code to perform the typical ARP for yourself check that I have seen before. Could someone please tell me if I have overlooked something or is this feature missing?
There is no explicit check for duplicate IP assignment. U-boot's networking code is intentionally minimalist and thus lacks many such features. Feel free to provide a patch and a convincing argument of why it's needed.
regards, Ben
Ditto on the patch.
WRT the convincing argument, I think the bar would be *really* low on this one. :-) I would consider a convincing argument to be "The nearly universal convention of performing an ARP to verify that the DHCP-assigned IP address is unused is missing."
Sure, this is a no-brainer. But, it shouldn't be limited to DHCP since having a dynamic address trouncing a static one is only one trouble scenario. Who knows, there may be people out there who object to the extra milliseconds that this ARP will add to boot time (not me).
regards, Ben
Ahh, so right. It is actually a worse risk for human-assigned addresses. s/DHCP-//
It would be simple enough to have a configurable ARP response wait timeout and use a special value (say <= 0) to disable the ARP test.
gvb
participants (3)
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Ben Warren -
Dan Batryn -
gvb.uboot