Static IP

[DSAGEY]

Hello,

 

I'm just wondering if anyone know the answer to my query.

 

I have a laptop that keeps picking up an IP address that is not accosiated with the school, I have done ipconfig/release and ipconfig/renew and it's not making a difference.

 

When I set it a static ip it works fine. My question is if I change the IP settings on the WiFi connection, does this alter the Internet Protocol Version 4 propetrties? I only ask because when I change it through the adapter settings when teachers take their laptop home, they then don't get internet connection.

 

Thanks

[Steve21]

If it's getting a wrong address does it show it's using the wrong DHCP server? Thinking like local software/rogue point etc

 

ipconfig /all | findstr /C:"DHCP Server"

Does that show your server IP?

 

If you do as you said and get a static IP it's on that card/nic rather than per wifi so would stay unless you're using cable one place etc

 

Steve

[DGardiner]

your wifi is either filtering off broadcast packets so its self asigning a 169. address or you have a misconfigured switch/ap/rogue dhcp server to look into

[TechMonkey]

What IP is it? Is it a 169 address?

[Jawloms]

It's not picking up a 169.254.x.x address is it?

[DSAGEY]

If it's getting a wrong address does it show it's using the wrong DHCP server? Thinking like local software/rogue point etc

 

ipconfig /all | findstr /C:"DHCP Server"

Does that show your server IP?

 

If you do as you said and get a static IP it's on that card/nic rather than per wifi so would stay unless you're using cable one place etc

 

Steve

No it doesn't show the server IP address

 

- - - Updated - - -

 

It is showing as a 169 IP address

[DSAGEY]

It's not picking up a 169.254.x.x address is it?

 

Yes it's showing with an 169. address

[TechMonkey]

As others have suggested, it isn't picking up a DHCP address. 169 IPs are generally MS locally assigned when it all goes horribly wrong.

[Davit2005]

We now have DHCP-SNOOPING setup on all edge switches but we also need to look at Rogue Access points soon.

 

We had one department who thought they were being clever and plugged in a router to give out the same IP address range that our DHCP servers were set to but it was not the first time this had happened to us.

 

On a laptop we managed to get the IP address of the DHCP server then pinged it then did an arp lookup found the MAC address then located the actual device. We were not best pleased after spending 2 weeks trying to troubleshoot random issues.

[DSAGEY]

As others have suggested, it isn't picking up a DHCP address. 169 IPs are generally MS locally assigned when it all goes horribly wrong.

 

How do I go about resolving it? I have reset the wifi/network card but still not picking up my IP range

[Davit2005]

How do I go about resolving it? I have reset the wifi/network card but still not picking up my IP range

 

If you have access to the WiFi can you see it's MAC address? Do you use DHCP reservations on the WiFi?

[Jawloms]

What make/model is the laptop and what make/model is the Wi-Fi card?

[DGardiner]

is your wifi unifi by any chance?

[DSAGEY]

What make/model is the laptop and what make/model is the Wi-Fi card?

 

I'd have to check this, but we have 5 of the same laptops, and the other 4 connect fine.

[DSAGEY]

is your wifi unifi by any chance?

 

Yes it is UniFi, we switched to this back in May last year, and have had issues ever since. It was changed to a Personal security or something because when it was setup as Business none of our old devices connected.

[DGardiner]

Yes it is UniFi, we switched to this back in May last year, and have had issues ever since. It was changed to a Personal security or something because when it was setup as Business none of our old devices connected.

 

Can you get into the controller?

 

Try rebooting the access points as a first step in there.

 

Then just to troubleshoot, in the site settings turn off auto-Optimise networks and wireless uplink - Wait for the aps to re-provisioning and try to reconnect the laptop

 

if that doesnt help

 

go to the SSID settings

 

Is Block LAN to WLAN multicast and broadcast data checked? if so is your DHCP server in that whitelist? (try turning it off anyway if its on)

Turn off multicast enhancements

Edited February 12, 2021 by DGardiner