Forum Discussion
Nimbostratuschange Vlan Self and Floating IP subnet mask
Will there a an impact/outage if i change the subnet mask of the self/floating IP of vlan.
here is the scenario..existing config
vlan 100 self IP is ACTIVE: 10.10.100.1/27 | STANDBY 10.10.100.2/27 | FLOATING : 10.10.100.3
Some server default gateway is pointing to floating IP....now i want to change the subnet mask to /26 to expand my IP range and my question is will there be an impact or outage if i change the subnet mask?
9 Replies
Cory_50405Noctilucent
If you are changing the subnet mask on the BIG-IP, then it's probably going to require some layer 2 changes on the network device that it's connected to. So you'll need to coordinate the subnet mask change on both the BIG-IP and on the switch/router/firewall that it plugs into. Make both changes simultaneously if you can. Doing so will minimize downtime, but I see no way to avoid downtime completely.
Meng_112830currently network/firewall/switches subnets configured as /26 but on the LB side it is configured as /27 now I wan to change it to /26 on the LB side.
- Cory_50405
Okay, so you are matching up the LTM with what's already configured on the network. This change should have very minimal impact, but could momentarily disrupt traffic. Best to do during after hours or during a maintenance window.
- Meng_112830
Getting this error message when changing the mask of floating or even the physical self IP mask.
01070601:3: A self IP matching the old network / mask 10.118.96.0 / 255.255.255.224 still exists in the configuration.
any good suggestion without deleting theself IP/floating just change the mask?
- Tim_Fogelquist_Did you ever get an answer to this? I am in the same exact spot.
- Cory_50405
One option is to manually edit (using vi) /config/bigip_base.conf, and change both your self IP and floating self IP masks. Then reload the config with 'tmsh load sys config'
Just labbed this out and worked like a champ.
- Domai_23823Perfect thank you...just implemented on non-prod and prod ltms.(11.4) As you said worked like a champ. But for some reason need to do this on active device first. Not Stby - including self ip. If I changed the self ip on Stby first it would revert back.
- Meng_112830
still getting same error when editing the base.conf and bigpipe.conf 01070601:3: A self IP matching the old network / mask 10.118.96.0.. deleting the floating IP and then change the self mask of physical device the re-create the floating will work this kind of solution.
- Cory_50405Ah, you're on v10. They changed some of the config files in v11, so I guess the self IPs were referenced elsewhere in v10. In v11, it's only in bigip_base.conf.
