Security

Hello,

we now working on organize the PC name and printer name in our the network, we create NAC policy in Clearpass to only give Vlan if the name is correct it work fine.

My problem is the endpoint hostname don't change immediately if they fix the name or change it, so the endpoint take the correct Vlan, 

we need to delete from the Clearpass or scan them to work is there a anyway to update them immediately  Automatically ??

Thank you

It depends where you get the hostname from. If it is from DHCP, the client may need to do a new DHCP and a CoA port-bounce (wired) can assist with that from the ClearPass side. Un/replug the cable (for a printer) twice may mork as well. If you get the hostname from a different source, that may be different.

Hello,

we now working on organize the PC name and printer name in our the network, we create NAC policy in Clearpass to only give Vlan if the name is correct it work fine.

My problem is the endpoint hostname don't change immediately if they fix the name or change it, so the endpoint take the correct Vlan, 

we need to delete from the Clearpass or scan them to work is there a anyway to update them immediately  Automatically ??

Thank you

Hello Herman,

About the hostname, I mean when changing locally in the device PC or Printer when will be updated in the clearpass ?? 

Thank you

It depends where you get the hostname from. If it is from DHCP, the client may need to do a new DHCP and a CoA port-bounce (wired) can assist with that from the ClearPass side. Un/replug the cable (for a printer) twice may mork as well. If you get the hostname from a different source, that may be different.

Hello,

we now working on organize the PC name and printer name in our the network, we create NAC policy in Clearpass to only give Vlan if the name is correct it work fine.

My problem is the endpoint hostname don't change immediately if they fix the name or change it, so the endpoint take the correct Vlan, 

we need to delete from the Clearpass or scan them to work is there a anyway to update them immediately  Automatically ??

Thank you

Hi

It depends on what attribute you are comparing when you evaluate the hostname of the host.

If it's the username sent during the autentication you should get the correct value. At least as long as the computer has an updated certificate with the new hostname. The forst line in the example above.

On the other hand, if you have a check in the Endpoints repository for the saved hostname, second rule in the picture above, it will still be the old information during the first authentication. Thats because the information in Endpoints repository is updated during the authentication and also by default have a 300 seconds cache.

Hello Herman,

About the hostname, I mean when changing locally in the device PC or Printer when will be updated in the clearpass ?? 

Thank you

It depends where you get the hostname from. If it is from DHCP, the client may need to do a new DHCP and a CoA port-bounce (wired) can assist with that from the ClearPass side. Un/replug the cable (for a printer) twice may mork as well. If you get the hostname from a different source, that may be different.

Hello,

we now working on organize the PC name and printer name in our the network, we create NAC policy in Clearpass to only give Vlan if the name is correct it work fine.

My problem is the endpoint hostname don't change immediately if they fix the name or change it, so the endpoint take the correct Vlan, 

we need to delete from the Clearpass or scan them to work is there a anyway to update them immediately  Automatically ??

Thank you

Hello jonas.hammarback,

So every time during the authentication the hostname will be updated correct ??, I checked in the Endpoints repository the Cache Timeout: is 0 is this by default ???  we don't change it

Thank you 

Hi

It depends on what attribute you are comparing when you evaluate the hostname of the host.

If it's the username sent during the autentication you should get the correct value. At least as long as the computer has an updated certificate with the new hostname. The forst line in the example above.

On the other hand, if you have a check in the Endpoints repository for the saved hostname, second rule in the picture above, it will still be the old information during the first authentication. Thats because the information in Endpoints repository is updated during the authentication and also by default have a 300 seconds cache.

Hello Herman,

About the hostname, I mean when changing locally in the device PC or Printer when will be updated in the clearpass ?? 

Thank you

It depends where you get the hostname from. If it is from DHCP, the client may need to do a new DHCP and a CoA port-bounce (wired) can assist with that from the ClearPass side. Un/replug the cable (for a printer) twice may mork as well. If you get the hostname from a different source, that may be different.

Hello,

we now working on organize the PC name and printer name in our the network, we create NAC policy in Clearpass to only give Vlan if the name is correct it work fine.

My problem is the endpoint hostname don't change immediately if they fix the name or change it, so the endpoint take the correct Vlan, 

we need to delete from the Clearpass or scan them to work is there a anyway to update them immediately  Automatically ??

Thank you

Are you doing (only) MAC Authentication on your network?

Are you using the hostname from the Endpoints Repository? That is either Endpoint:Hostname, or Authorization:[Endpoints Repository]:Hostname

That information is NOT changed during authentication. If you did not do anything special, that hostname is learned from DHCP through DHCP relay/ip-helper to your ClearPass. The DHCP happens after the authentication and requires some form of network access (so you can't reject access), and you can force/trigger a DHCP by bouncing the switch port (on wired networks); but just be aware that if the hostname on a device is changed, in the first re-authentication/port-bounce there has not been a new DHCP, so it's expected that you see the old name; then the DHCP may update the hostname and then you may need an additional re-authentication. Please work with your Aruba partner or TAC, as it may be hard to understand what's going on without a full overview of your network and setup. It's just guessing for me what you may be doing.

Hello jonas.hammarback,

So every time during the authentication the hostname will be updated correct ??, I checked in the Endpoints repository the Cache Timeout: is 0 is this by default ???  we don't change it

Thank you 

Hi

It depends on what attribute you are comparing when you evaluate the hostname of the host.

If it's the username sent during the autentication you should get the correct value. At least as long as the computer has an updated certificate with the new hostname. The forst line in the example above.

On the other hand, if you have a check in the Endpoints repository for the saved hostname, second rule in the picture above, it will still be the old information during the first authentication. Thats because the information in Endpoints repository is updated during the authentication and also by default have a 300 seconds cache.

Hello Herman,

About the hostname, I mean when changing locally in the device PC or Printer when will be updated in the clearpass ?? 

Thank you

It depends where you get the hostname from. If it is from DHCP, the client may need to do a new DHCP and a CoA port-bounce (wired) can assist with that from the ClearPass side. Un/replug the cable (for a printer) twice may mork as well. If you get the hostname from a different source, that may be different.

Hello,

we now working on organize the PC name and printer name in our the network, we create NAC policy in Clearpass to only give Vlan if the name is correct it work fine.

My problem is the endpoint hostname don't change immediately if they fix the name or change it, so the endpoint take the correct Vlan, 

we need to delete from the Clearpass or scan them to work is there a anyway to update them immediately  Automatically ??

Thank you

Hello Herman,

We will test the hostname when will is changed in cppm.

about your question 

are you doing (only) MAC Authentication on your network? 

No, both MAC Authentication and 

Are you using the hostname from the Endpoints Repository?

yes for some devices like printers and active directories for PC

The authentication works Like this:

• The first time PC connects check the hostname: 
  • if not correct don't give any IP.
  • if correct go to untrust Vlan to join the PC to the domain, after that bounce to the correct Vlan.
• The first time for any other device  not PC:
  • go to untrust Vlan, after that bounce to the correct Vlan.

Thank you

Are you doing (only) MAC Authentication on your network?

Are you using the hostname from the Endpoints Repository? That is either Endpoint:Hostname, or Authorization:[Endpoints Repository]:Hostname

That information is NOT changed during authentication. If you did not do anything special, that hostname is learned from DHCP through DHCP relay/ip-helper to your ClearPass. The DHCP happens after the authentication and requires some form of network access (so you can't reject access), and you can force/trigger a DHCP by bouncing the switch port (on wired networks); but just be aware that if the hostname on a device is changed, in the first re-authentication/port-bounce there has not been a new DHCP, so it's expected that you see the old name; then the DHCP may update the hostname and then you may need an additional re-authentication. Please work with your Aruba partner or TAC, as it may be hard to understand what's going on without a full overview of your network and setup. It's just guessing for me what you may be doing.

Hello jonas.hammarback,

So every time during the authentication the hostname will be updated correct ??, I checked in the Endpoints repository the Cache Timeout: is 0 is this by default ???  we don't change it

Thank you 

Hi

It depends on what attribute you are comparing when you evaluate the hostname of the host.

If it's the username sent during the autentication you should get the correct value. At least as long as the computer has an updated certificate with the new hostname. The forst line in the example above.

On the other hand, if you have a check in the Endpoints repository for the saved hostname, second rule in the picture above, it will still be the old information during the first authentication. Thats because the information in Endpoints repository is updated during the authentication and also by default have a 300 seconds cache.

Hello Herman,

About the hostname, I mean when changing locally in the device PC or Printer when will be updated in the clearpass ?? 

Thank you

It depends where you get the hostname from. If it is from DHCP, the client may need to do a new DHCP and a CoA port-bounce (wired) can assist with that from the ClearPass side. Un/replug the cable (for a printer) twice may mork as well. If you get the hostname from a different source, that may be different.

Hello,

we now working on organize the PC name and printer name in our the network, we create NAC policy in Clearpass to only give Vlan if the name is correct it work fine.

My problem is the endpoint hostname don't change immediately if they fix the name or change it, so the endpoint take the correct Vlan, 

we need to delete from the Clearpass or scan them to work is there a anyway to update them immediately  Automatically ??

Thank you