DHCP Backup

[TrebleTA]

Is there a way to back up my DHCP list so I can just copy the list back after a new firmware flash and reset?

 

[Tech9]

Yes. Few different ways. All discussed on SNB Forums. Do a quick Search, please.

 

[TrebleTA]

I did a search for DHCP back up but got other stuff, else would not of asked. I will play with the search more. And found.. thank you

 

[bbunge]

As

Is there a way to back up my DHCP list so I can just copy the list back after a new firmware flash and reset?

There has been some recent discussion about this and how it is harder now that Asus has increased security. It was in the Asus Official area discussing AX86U fir,ware upgrade. I looked but could not find it

 

[Tech9]

@TrebleTA is perhaps using Asuswrt-Merlin fork and SCP is still there.

 

[Tech9]

And found.. thank you

I don’t like sending people to search, but you could help a bit with router model and firmware version. I had to search your older posts to find what you are using.

 

[TrebleTA]

Thanks for the replys, I have a dsl ax82u I use merlin Fw fork also stock at time to compare. So I at mo always having to key dhcp back.
So looking for a simple way to transfer across builds.
I will be working from a pc using windows 11 SSH.

 

[Tech9]

You need to transfer some files from /jffs/nvram. I usually save dhcp_staticlist, custom_clientname, custom_usericon. Use WinSCP to copy/paste. File names explain what they contain.

You can find more detailed information. I’m on a phone at the moment and it’s hard to copy links for you.

 

[TrebleTA]

So I can save to jffs?
I run,
nvram get dhcp_staticlist

Nvram show | sort /jffs/settings.txt
Then how do I copy the file, CD jffs
Copy settings.txt ??? Am lost here how do I link to the pc.
Same on my mobile also at mo

I prob better using a usb stick and making a temp folder like dhcp and just save there?
So would be nvram show | sort /dchp/settings.txt
Is that right?

 

[Tech9]

Use WinSCP, copy the files from /jffs/nvram to your Windows desktop, reset the router, restore the files to /jffs/nvram. Reboot the router. Now you have all your DHCP reservations, user names and icons as before. Of course, you have to do some minimal configuration after reset and enable ssh, but you perhaps already know that.

 

[TrebleTA]

Hmm so what's this winscp.... will investigate. Thanks for helping
Looked and not really intrested in a app when it can be done with out having to install stuff on to the pc.
Also I dont always enable jffs.
I am a noob to SSH and router stuff yet know a pc backwards just not played with linx etc im more ms dos, windows etc

 

[Tech9]

You don’t have to install anything. As I said, there are few different options. Chose the best one for you.

 

[TrebleTA]

Going to try when I up the nvram way I think all I need is ssh enabled and a usb. Just not totaly sure on the command line till I'm awake and at my pc.

 

[TrebleTA]

nvram show | sort /mnt/sda1/dchp/settings.txt

An I right in thinking that mnt = mounted sda1 = say a:\ being the first connected device?

Will know try more when at my pc else will this work too
nvram get dhcp_staticlist > /mnt/sda1/tmp/dhcp.txt

Then to restore
nvram set dhcp_staticlist=`cat /mnt/sda1/tmp/dhcp.txt`
Then once done can disable usb etc?
Is the correct?
thanks again

 

[tgl]

You might not actually need to do anything. Commonly, DHCP clients will try to extend their existing leases when those run low, and if the DHCP server is well-written it will hand out that address again as long as it doesn't have a record of a contrary allocation. So from the point of view of the clients it can be a pretty seamless transition from an old DHCP server to a replacement one (... or the same server with its allocation database wiped). I've definitely seen this happen when switching to a backup DHCP server on Ubiquiti EdgeRouters, and I think it may be part of the DHCP spec.

If you've got any particularly critical clients where you don't want them changing addresses, then you shouldn't be relying on DHCP for them in the first place. Assign them fixed addresses outside your DHCP range, instead. (Yeah, I know about configuring your DHCP server to hand out predetermined IP addresses to specific MAC addresses. I use that feature too, but not for critical clients.)

 

[TrebleTA]

What's that got to do with backing up the dhcp list?

 

[ColinTaylor]

nvram show | sort /mnt/sda1/dchp/settings.txt

This is completely wrong.

nvram get dhcp_staticlist > /mnt/sda1/tmp/dhcp.txt

Then to restore
nvram set dhcp_staticlist=`cat /mnt/sda1/tmp/dhcp.txt`

This is better.

Or just use the WinSCP method.

 

[TrebleTA]

This is completely wrong.


This is better.

Or just use the WinSCP method.

Nice one will be trying shortly

 

[bbunge]

What's that got to do with backing up the dhcp list?

He is saying that setting a long list of reserved addresses is nuts. The clients will get the same address from DHCP...maybe. The better way is to assign static IP addresses at the client. If the client can't do static addresses get rid of it ot live with what DHCP gives it.

 

[TrebleTA]

I was asking about backing up DCHP not how to use, so its not what I was asking, I use DHCP to use QOS bandwidth on some devices.
also I do not own all the devices so saying hay can I just set up your device is a pain in the arse. also I use Parental Controls.

Back to the topic....
nvram get dhcp_staticlist > /mnt/sda1/tmp/dhcp.txt
sda1=device name of the usb device. else worked fine got the text out put. Notice the output is a bit out of sync but can work with that thanks.