dhcp on vlan default

New, Summit 460 G2 running 15.6.0b12. A show config has the normal, empty config with the exception of the following section:

# Module netTools configuration.
enable dhcp vlan Default

This has not been present in the configs on any of the other, (3) new, 460G2's that I have been working on. I am unable to delete the line, and consequently, can't assign an ip address to the default vlan.

disable dhcp vlan all
WARNING: VLAN "Default" is not configured as a DHCP client

configure "Default" ipaddress
Error: DHCP/BOOTP is enabled on the VLAN

disable bootp vlan all
WARNING: VLAN "Default" is not configured as a BOOTP client

trying again.....
configure "Default" ipaddress
Error: DHCP/BOOTP is enabled on the VLAN

Background: I started out by having a stack of (2) 460 G2's. That is when I first saw the issue. I unconfigured the stack and looked at the config on the master 460. It did not have the "enable dhcp vlan Default" line. Checking the secondary switch it did. Somehow when I create the stack, this command is being applied from the secondary config to the stack config. I also upgraded xos to 15.7.1b4, but that didn't make any difference.

Anyone got any ideas on how this is happening or how to get rid of it?

5 replies

Userlevel 5

I seem to remember running into that problem early on before product was released with beta code but haven't seen it on any current firmware, 15.6.1 and later...

Did you unconfigure the stack or just remove it and load it as its own master? Here is what I would try... if you have a config on the switch you need, save it off as a text file "save config as-script " - Then, vi from the file name you created earlier and in the vlan section remove the line "enable dhcp vlan default" - :w to save and then issue a "unconfigure switch all" - Upon reboot you should have a clean startup into factory default...

Check to make sure all if clean and then run the command "load script " - and you will be (hopefully) configured without DHCP enabled on the default vlan.

Let me know!

Userlevel 5

Just realized that you are running which is pre-ga code that shipped with original models, this was due to the fact the hardware was shipped before the GA code was ready. You will run into that issue with pre-ga (15.6.1.x or later) code, not sure why but I had a similar issue as I said above. Make sure you get 15.6.1.x or later....

Userlevel 6
Hey Chris

Did you do the factory reset after the 15.7 code upgrade? And are you still seeing the issue?

Userlevel 7
Hi Chris,
I wanted to point out that EXOS 15.7, which you mentioned trying, includes a new feature called "Zero Touch Provisioning."
Part of this is the addition of enabling DHCP by default on the Default and mgmt VLANs. That would be why you're seeing it present.

Here's some more info on ZTP.

As Bill mentioned, you'll want to get on to an actual Generally Available (GA) version of code. At present, the latest 15.6 is v15.6.2.12-patch1-1. There's also v15.7.1.4.
Once upgraded, you shouldn't see the dhcp line in the config. It will be active, however.

I just did a quick test in the lab and I had to unconfigure the ipaddress before I could save a new one.

edit: I was going to post the CLI example, but it insists on showing raw HTML special characters...
I should have included that the first step I took was to upgrade the switches to 15.7.1b4 before attempting any configuring.

This is what I did today just to see what would work:

On the 2nd switch, ran "unconfigure switch all", saved, and then rebooted to 15.6 partition. Dhcp line was gone. Changed partition to 15.7 partition, rebooted and dhcp line was back again. However, I was now able to assign an ipaddress to the default vlan. Progress.

Current config > primary switch, 15.7, no dhcp line (can assign IP). 2nd switch 15.7, still has dhcp line (but could now assign IP to default vlan). Built the stack, dhcp line is present, can not assign ip address to default vlan.


Unconfigured stack, ran "unconfigure switch all" on 2nd switch, save config and rebooted to 15.7. Dhcp line still present in 2nd switch. For grins, I unconfigured the switch a 3rd time and rebooted. This time I left the 2nd switch a the initial config prompt. Went back to primary switch and rebuilt the stack.

Dhcp line is present, and I can not assign an ipaddress to the default vlan.

Then, I attempted what Bill had suggested in his first post. I unconfigured the stack, copied off the newly created .xsf file from second switch, edited out the line, reloaded (etc, etc, etc) and the net result was the exact same issue.

I unconfigured both switches again, and pulled the primary.cfg files off to do a side by side comparison. As expected, the difference was the one dhcp line on the second switch. I removed the line and reapplied it to the switch. Rebooted the 2nd switch and verified that the line was still gone from the config. It was, so I rebuilt the stack, and upon reboot, the dhcp line was back in the stack config and I could not assign an ip address to the default vlan.

This time, I pulled the primary.cfg off of the stack, deleted the dhcp line and reapplied the file. Rebooted the stack, and verified that the line was still gone from the config.

Set an ipaddress on the default vlan and I was good to go. Exactly what should have happened yesterday.

Thank you all for your suggestions. Why this particular switch was different than the others after the upgrade to 15.7 I can not say, However, the dhcp line was definitely there post upgrade.