Same MAC address LAN different segment, different ESX, different groupings? questions?

Similar Questions

• same mac address lan on different esx hosts

  Hi, I have a unit of vmware (firewall) who take control of the NICs mac address, if I move this to another Esx VM, all configuration fell, because the lan mac address is different from the first Esx.

  Is there a way to put the same mac address on two or more Esx host in the network adapters.

  I tryied to set the mac address on the settings of the VM manually from the second Esx, but the first part is blocked.

  In this case, I suggest to make a manual copy.

  Or remove the inventory on the destination hosts, set the vmx file (to restore the old MAC address), then add back to the inventory.

  André

• exit show me the same MAC address twice

  Hi all

  and easy for sure. When I run the interfaces see the G0/1 command on switch, why the output shows me the same MAC address twice?

  the address is 00d0.58c0.4519 (bia 00d0.58c0.4519)

  I know, BIA is burned in address and is located on the ROM, but what is the idea behind this?

  EDIT: also would like to ask, why a router maintains an arp entry for its own interface, it seems that this is not the case on for example a Windows laptop...

  Best regards

  Adam

  Adam,

  Some interfaces allow you to configure user-defined MAC address:

   R1#show int f0/0 | i bia Hardware is AmdFE, address is cc00.0fac.0000 (bia cc00.0fac.0000) R1#conf t Enter configuration commands, one per line. End with CNTL/Z. R1(config)#int f0/0 R1(config-if)#mac-address 0200.0000.0001 R1(config-if)#do show int f0/0 | i bia Hardware is AmdFE, address is 0200.0000.0001 (bia cc00.0fac.0000)

  HTH

  Rolf

• 4 devices using the same mac address in the ARP Table. Explanation

  Please tell me why four devices connected to the router shares the same mac address was shown on the arp table? I know this has to do with the firewall and owner of listening devices, but why all using the same mac address instead of him? I'm trying to understand this scenerio. Please advice.

  Internet 16x.1x.2x.1x - 0050.5486.5f60 ARPA Ethernet0/0

  Internet 16x.1x.2x.1x 1 0040.1017.2d64 ARPA Ethernet0/0

  Internet 16x.1x.2x.1x 11 0040.1017.2d64 ARPA Ethernet0/0

  Internet 16x.1x.2x.2x 216 0040.1017.2d64 ARPA Ethernet0/0

  Internet 16x.1x.2x.2x 88 0040.1017.2d64 ARPA Ethernet0/0

  Internet 16x.1x.2x.2x 166 0040.1017.2d64 ARPA Ethernet0/0

  No problem at all... I guess she gave us the opportunity to learn that a little on the proxy-ARP and the potential for problems, it can cause.

  Paresh

• SG500 showing the same MAC address on more than one port?

  My ISP has been help me solve a problem that we had with an interaction between our SG500 battery on HP customer premises equipment.

  I have the stack of SG500 divided into two VIRTUAL LANs. 8-port VLAN11 and the rest on VLAN1. Both are of VLAN native, not marked so they will carry only the traffic for their own VLAN with no mixing. I also route between these VLANs on the stack.

  VLAN11 switch ip: 10.76.20.20

  IP switch VLAN1: 10.1.1.1

  I took a port for each VLAN and plugged into the HP PSI switch, where he adapt VLANS separated which then connect to a remote data center through an MPLS.

  Here's the question: the SG500 seems to have mac address base on two HP PSI switch ports. This disrupts the HP switch, and I end up having packets to fall into a black hole. This is the output of the switch from HP showing mac based battery SG500 goods between ports in seconds:

  HP # display the address mac 8843e1-af7085

  Status and counters - Address-Table - 8843e1-af7085

  MAC address: 8843e1-af7085

  Located on the Port: 15

  HP # display the address mac 8843e1-af7085

  Status and counters - Address-Table - 8843e1-af7085

  MAC address: 8843e1-af7085
  Located on the Port: 11

  Any idea what's going on here? It's as if the SG500 uses the MAC even for both its IP addresses.

  Thank you!

  Hi Dani, the only MAC address announced by SX300/500 series should be the Mac system if you show on the SX500 mac address table, you should see the MAC even for both VLAN. I don't know why, is to confuse the HP switch unless it does not correctly between switches vlan tag.

  -Tom
  Please mark replied messages useful

• ESX uses network adapter with the mac address that is different than virtual connect reports

  Hi all

  Our ESX environment consists of HP C7000 enclosure, virtual connect 1 gb ethernet with a mixture of BL480c and BL460c. We just bought some new BL460c G7 with NIC NC553i to replace some of the oldest BL480c. We have configured Virtual Connect to assign mac addresses. In vc management consoleI see the addresses assigned to the server, but when I start the server displays a different mac address for nic #2 that vc does. NIC #1 has the same mac address of console management vc and in the server BIOS. When I install ESX also sees the 'wrong' for #2 nic mac address. According to vmware nic #2 has not any network connected to what should be if it was really nic #2 (according to the vc management console).

  When I look at the mac addresses in the BIOS none of the network interface card have the mac address assigned by vc. VC firmware is 3.01. I have attached the photos I see information in the management of VC and BIOS console. Someone at - it for clues to what is happening and how can I solve it? Thanks in advance.

  Kind regards

  GB

  Please refer to:

  http://KB.VMware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalID=1001167

  Note:   The ESX host uses following addresses starting with 00:50:56 (as opposed to the address embedded in the interface itself).

  To determine the MAC address of the interface Board of the ESX host, run the command:

  # ifconfig | grep-i hw

  The output looks like:

  vswif0 Link encap HWaddr 00:50:56:41:5 A: 59

  The MAC address is in the first line after HWaddr.  In this example, the MAC address is 00:50:56:41:5 has: 59.

  Note:   The ESX host uses following addresses starting with 00:50:56 (as opposed to the address embedded in the interface itself).

  You can also review the output information and the esxcfg-NICS - l order MAC addresses.

• Unique mac address of guaranteed for a VM on an ESX?

  Hello

  Please can someone help me understand how the ESX (i) ensure a unique virtual computers mac address assignment to the host.

  for example, let's say that if I have a virtual machine with the address mac x, then how do I gurantee ESX me it won't any other virtual computer with the same mac address in the same ESX host.

  Also, any idea on how these mac addresses are assigned to the VMs. is it a MAC common address by ESX resource pool?

  Thank you.

  If your ESX is managed by vCenter, then the MAC addresses are assigned from a pool that she maintained.  The vCenter monitoring assignments, and a duiplicate should be detected during VM startup (as a result of a clone to the virtual machine, for example), then a new MAC address is assigned to the pool.  Each vCenter has a unique ID, and so your vCenter have different unique ID they will not affect the same MAC

  It is possible duplicates to happen, if you have deployed masses of the VM vCenter pool can run out (not sure what the size of the pool is) and re - get used to MAC (but if you have masses of machinery the chances of both MAC duplicate appearing on the same subnet are probably very thin)-see http://kb.vmware.com/kb/2006344.  In addition, if you manually assign MAC addresses, then I think not that the vCenter will search for a duplicate of the one at boot time.

  I guess that standalone ESX work pretty much the same way, maintain their own pool tio divy out ot VM MAC, using their unique ID to ensure that two ESX do not have the same basins.

• Same range of MAC addresses with vSphere 2 Virtual Center

  Hello, we have two virtual center of vSphere that create VM with the same MAC address range,

  00:56:B0:00:00... the other a virtual center... so be very carefully to not

  VM in duplicate with the same mac address...

  Could I change attribution AUTOMATIC of the beach of one of our virtual centres?

  Thank you very much

  ---

  
  Francisco Javier Morales Lopez of Gamarra

  VMware VCP | LPI - CCNA

  Edited all the line caps object according to the rules of the forum, AWo.

  If you have two vCenter servers to ensure that they have different instance ID because they are used to generate MAC and UUID for VM addresses...

  This is explained in this KB here: http://kb.vmware.com/kb/1024025

  / Rubeck

• Advantage of the MAC address cloning?

  What is the advantage of the MAC address cloning?

  There is no "advantage" to clone the MAC address. The only benefit would be to have internet or not.

  In many cases, it is absolutely useless to use the clone MAC address. If you have an internet connection through your router, then there is no need to use the MAC address cloning feature.

  Only when you find that you have a working internet connection on a computer directly on your modem, but not when you connect through the router (or another computer directly into the modem) then it is necessary to use the MAC address cloning feature.

  Usually, this is only the case with cable TV ISP. They allow you to have an active internet connection single at any time. They do this by remembering the MAC address which connects via a specific modem. If you connect first a computer for testing directly to your modem, you will have an internet connection. Now if you connect a different device to your modem it does not work is because the ISP has always blocked the internet connection, the MAC address of the first computer.

  How to remove the lock depends on the ISP and the modem. Sometimes just reset the modem or to turn everything off. Sometimes you turn off everything for a few hours and after that the first connection device is the one with the internet connection (i.e. make sure you connect the router then...) If you want to know exactly how your ISP to do this, you need to ask...

  The simple solution is to use the MAC address cloning feature. The router "clones" the MAC address of the first computer, i.e. it basically pretends to this computer. The MAC address is accepted by the ISP and is immediately authorized to the network. You have a working internet connection on the first computer, either through the router directly because both use the same MAC address. (This is no problem on the router because the MAC address is used on the internet port only...).

  Of course, remember all this. If at some point later, you connect another computer directly to the modem (for example you have connection problems and want to know what is wrong) you can "lock" in a different MAC address for your connection and you will have to wait to find the connection to a different device.

  But once again: there is absolutely no need to use the clone if you have an internet connection through your router.

• Static MAC address starting not not by 00:50:56?

  Hello

  I have a quick question before I go to bed (so I have no time for some tests).

  I just found this article on the static of MAC addresses: VMware KB: defining a MAC address of a NETWORK card virtual

  The article says that "VMware uses a different YES to manually generated addresses: 00:50:56.»  But can I use the autogenerated, MAC address that starts with 00: 0c: 29 (and of course ensure that ESXi uses the same MAC address for an another VM)?

  Thank you

  Hello..

  Both are actually automatically generated... 00: 00c: 29 is generated by the host ESXi itself when not associated with an instance of vCenter. 00:50:56 is generated by vCenter if the ESXi host is attached to the phone.

  But can I use the autogenerated, MAC address that starts with 00: 0c: 29 (and of course ensure that ESXi uses the same MAC address for an another VM)?

  Yes...

  / Rubeck

• When issuing vNIC with the same MAC on the same vSwitch

  Hi all

  In a public cloud computing environment, only host hypervisor (VMWare ESXi for example) can host VMs of different customers. These virtual machines can use the same MAC address for the vNIC. What happens if these virtual machines with the same MAC connected to the same vSwitch by chance? This will cause the MAC table on the vSwitch updated constantly which would lead in turn to the performance problem.

  How vSwitch or what type of solution could solve this kind of issue and provide a network environment isolated to each cloud tanent?

  Thank you!

  It would be on the cloud provider (who generally do not use vSphere anyway) to mitigate.

  If you are a supplier, you can use something like vCloud to isolate your environment shared with the support of as vShield products and technologies such as VXLAN.

• Meet multiple IFs with the same MAC, why limited?

  Hello

  I'm currently testing a configuration with a controlled 802.3ad bundle a Linux guest and an external switch via 2 vNIC / hnics.

  Each vnic is in a group of different bridge, so I assume that the workstation should not have any problem with both receiving the same MAC address, but it does.

  Is there a magic wand shot to disable this check? Or what is there is only one table mac address in the vswitch so it won't work?

  TIA,

  -Carlos

  ethernet0.ignoreMACAddressConflict = 'true '.
  ethernet0.checkMACAddress = "false".
  ethernet0.noForgedSrcAddr = "false".

  try any or all of these parameters in the vmx file read
  http://sanbarrow.com/VMX/VMX-network-advanced.html

• L2PT multicast mac address

  I have a question about L2PT, especially from this documentation:

  http://www.Cisco.com/en/us/docs/switches/LAN/catalyst3550/software/release/12.2_25_seb/configuration/guide/swtunnel.html#wp1005050

  To my knowledge, when switch PE l2pt receive a bpdu, it will replace the destination MAC address by owner of Cisco (01-00-0c-cd-cd-d0) multicast address. This MAC address will be used until the BPDU packet reaches the output PE.

  According to the Cisco documentation:

  The edge lights up catering out side the appropriate layer 2 Protocol and the MAC address and transfer the packets to all ports of tunnel or access on the subway even VLAN. Therefore, the layer 2 PDU remain intact and are sent over the network from the other side of the client network service provider.

  
  

  ... When packets double marking enter switch D, the tag VLAN 40 metro is removed. The MAC address is replaced by the Protocol Layer 2 respective MAC address and the packet is sent to the customer Y Site 2 as a single frame in VLAN 100.

  If I get it correctly, then it means that the MAC address of the destination output switch returned to the original BPDU MAC address (for example the CDP multicast address). My question is, if the destination MAc was crushed, how know MAC address of origin output switch?

  Second question: is the address 01-00-0c-cd-cd-d0 MAC used for all protocols BPDU tunnel? Or is there another MAC destination for each Protocol (01-00-0c-cd-cd-d0 CDP, something else for STP, etc.). If it's the same thing how the output switch knows what protocol the BPDU belongs to?

  Thanks in advance.

  Hello Sultan,

  note

  > If the destination MAc was crushed, how does the output switch know the original MAC address?

  a protocol in the frame type field allows to rebuild the right destination, MAC address, most of these frameworks use LLC/SNAP encapsulation and it is not deleted.

  See

  LAN password best practices IOS, it contains a table with all types of Protocol CDP, DTP, VTP and so on

  http://www.Cisco.com/en/us/products/hw/switches/PS700/products_white_paper09186a00801b49a4.shtml

  Hope to help

  Giuseppe

• MAC addresses

  Can two separate devices connected to the internet cause the same mac address?  For example, an iPhone and an iPad?

  As long as they do not use the same Ethernet or wireless, Yes.

• VM mac address

  I migrated about 40 virtual machines from a virtual centre to the new virtual centre along the esxi host.

  now, I'm having a problem of duplicate MAC address. a few times my old vcenter takes a MAC address of a new vcenter.

  How this can happen and how to stop it.

  Another way rather than change the MAC address of the virtual machines attached with my new virtual centre.

  Thank you

  Hello

  When using multiple vCenter make servers you define unique ID on each vCenter. In this way, they don't use the same MAC address range.

  This will help only for VMS newly created however. I'm afraid you must change the Mac of your existing virtual machines or delete their network cards and create new ones.

  Read more:

  http://KB.VMware.com/kb/1024025

  Considerations when migrating VMS between vCenter servers | virtuallyGhetto