• Status: Solved
  • Priority: Medium
  • Security: Public
  • Views: 625
  • Last Modified:

NLB

hi guys

i have always had my NLB cluster working fine but it stopped working recently.

It only works now if i assign a new IP to the cluster (this changes the mac obviuosly)

when i try to use the original IP address then i get an address conflict  - if i just try and assign this IP to a device outside the vlan attached directly to the physical switch then it dosent give me any conflict!

any ideas where this  conflict would be coming from?
0
mikeleahy
Asked:
mikeleahy
  • 6
  • 5
  • 4
  • +1
2 Solutions
 
irweazelwallisCommented:
check the bindings on the NIC's it might still be lingering on there.

To reset the whole thing delete and reinstall the NIC's and then setup the NLB again
0
 
Packiyaraj NCommented:
Pls use IP scan freeware and search the hole subnet,you will find which machine is using your NLB IP,or pls do nbtstat -a <IPaddr> you will find where is the conflict.


Regards
Packi
0
 
Andrew Hancock (VMware vExpert / EE MVE^2)VMware and Virtualization ConsultantCommented:
When NLB is not in use, what is the MAC Address of the IP Address conflict?
0
Concerto's Cloud Advisory Services

Want to avoid the missteps to gaining all the benefits of the cloud? Learn more about the different assessment options from our Cloud Advisory team.

 
mikeleahyAuthor Commented:
hwo do i check the binding on the nics?
0
 
irweazelwallisCommented:
network settings.
Right click on the adapters

TCP IP V4
Properties
Advanced and the first tab shows any additional IP set on the NIC
0
 
mikeleahyAuthor Commented:
hancock

the mac address that shows when the conflict happens is that of the firewall !

does this mean something?
0
 
Andrew Hancock (VMware vExpert / EE MVE^2)VMware and Virtualization ConsultantCommented:
Have the static arp mappings been changed on your network equipment?
0
 
mikeleahyAuthor Commented:
no - we dont use static arp mappings as its a redundant environment
0
 
Andrew Hancock (VMware vExpert / EE MVE^2)VMware and Virtualization ConsultantCommented:
Oh, normally you do for Windows NLB to work, are you using Multicast?
0
 
mikeleahyAuthor Commented:
yes i am but if works fine if i use one ip for example 192.168.1.119 but .120 wont work at all. it will say there is a conflict and the firewall mac is responsible for it
0
 
irweazelwallisCommented:
have anyone change the MAC's of either the NLB or the firewall

if you use nlb.exe ip2mac you can check what the default MAC address is

If you are really stuck - use the MAC generated by the .120 NLB address and force it onto the 119 address
0
 
mikeleahyAuthor Commented:
where do i use nlb.exe ip2mac?

sure you cant change the mac of the Nlb? its greyed out in the cluster properties
0
 
irweazelwallisCommented:
you are right can't change the MAC of the NLB - getting my technologies mixed up

nlb.exe is the command line utility that is installed with the NLB role or admin tools

you can run from any machine and use nlb.exe ip2mac "clustername"

0
 
mikeleahyAuthor Commented:
if u use multicast nlb with 2 nodes - do they share the same mac for the cluster 00:30 etc or does  each node have a different mac for the cluster and those are mapped to the cluster mac ?  if that makes any sense
0
 
irweazelwallisCommented:
the cluster MAC address is shared - the NLB then manages the bits behind the scenes

just found this Technet article which may help you - it explains it and also offers a way to force the MAC

http://support.microsoft.com/kb/232454
0
 
Andrew Hancock (VMware vExpert / EE MVE^2)VMware and Virtualization ConsultantCommented:
if you are using multicast, you usually statically allocate the ARP tables in your network equipment, against a physical port where the servers are connected.

does your NLB converge and work?
0

Featured Post

Free Tool: IP Lookup

Get more info about an IP address or domain name, such as organization, abuse contacts and geolocation.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

  • 6
  • 5
  • 4
  • +1
Tackle projects and never again get stuck behind a technical roadblock.
Join Now