Network questions

I notice that the dhcp system does a microsoft style 169 address if no server is avalable.

Is there any way this can be user defined? (So I can be on the same subnet as my client wifi access point to access the control panel.)

(I think I already asked this
Should the Pi network card automatically switch itself when a crossover cable would otherwise be needed?

Thanks

I notice that the dhcp system does a microsoft style 169 address if no server is avalable.
Is there any way this can be user defined?

The behaviour is what MS label APIPA (Automatic Private IP Addressing) and 169.254.0.0/16 is the designated range. The feature could probably be made configurable but that wouldn’t be a legal feature of the network stack.

There is another feature in other stacks that allow the setting of an alternate address such that an interface that doesn’t get a DHCP offer will use an alternate configuration where APIPA is an option and manually assigned IP is another.
e.g. Windows – network properties – TCP/IP — properties – alternate configuration.

Off hand I think the feature is provided by ZeroConf in BSD (there appears to be a ZeroConf module in Select (for the same purpose?)

Sounds like a wish list item.

Are there commands that can reset the ip address on the fly and set it back to dhcp?
ta

I assume you’re asking about Select? Couldn’t say without digging through any public documentation as I don’t have a copy – however I have been looking at the documented features of the modules in Select to try and spot differences to the set in 5.19.
People keep asking whether ROOL can match their favourite bit of Select and really speaking what they need to do is identify the features and the related portions of the OS.
Perhaps Select owners could contribute specific comparisons…

I have noted that Select was modified to allow IP settings changes on the fly (no reboot)

Anyway – if I was using the windows laptop I have here at work right now – the change method I would use is to save the current settings using NETSH INT IP DUMP > SET1.TXT then make changes to the settings I want and use NETSH INT IP DUMP > SET2.TXT

After that you have two text files describing particular settings and they can be loaded with NETSH EXEC SET1.TXT or NETSH EXEC SET2.TXT

So, the stack has rebooted, a few tests and go home…

Are there commands that can reset the ip address on the fly and set it back to dhcp?

You can *DHCPEXECUTE at any time you want, since that’s all the boot sequence does, there’s no magic.

You can *DHCPEXECUTE at any time you want,

…provided you specify the interface you are targeting.
No interface specified will just produce a response telling you the command syntax.

As Jess has raised the issue, what would be useful is if the -p option was
[-p []]
i.e. If the DHCP server is not seen the default is to assign a 169.254.×.x/16 address OR optionally assign a specified IP Address.

1. Request DHCP assigned IP – if success complete and end else fail and goto 2
2. Check for user assigned IP, if set use user assigned, if not set then assign 169.254.×.x/16 address.