ACE virtual mac address allocation

We're running ACE SM and seeing all the VIP addresses, NAT addresses and alias addresses in the ARP table below being assigned the same virtual MAC address. How then would a packet find the correct source/destination if all these MAC addresses are the same?
IP ADDRESS      MAC-ADDRESS        Interface Type      Encap NextArp(s) Status
================================================================================
204.107.54.1    00.24.f9.03.08.00 vlan810   GATEWAY    300    263 sec      up
204.107.54.4    00.1e.13.3c.ab.80 vlan810   LEARNED    24     7631 sec     up
204.107.54.5    00.1e.13.3c.a6.00 vlan810   LEARNED    331    8992 sec     up
204.107.55.5    00.1f.ca.7b.70.23 vlan810   INTERFACE LOCAL     _         up
204.107.55.6    00.0b.fc.fe.1b.05 vlan810   ALIAS      LOCAL     _         up
204.107.54.20   00.0b.fc.fe.1b.05 vlan810   VSERVER    LOCAL     _         up
204.107.54.21   00.0b.fc.fe.1b.05 vlan810   VSERVER    LOCAL     _         up
204.107.54.22   00.0b.fc.fe.1b.05 vlan810   VSERVER    LOCAL     _         up
204.107.54.23   00.0b.fc.fe.1b.05 vlan810   VSERVER    LOCAL     _         up
204.107.54.31   00.0b.fc.fe.1b.05 vlan810   VSERVER    LOCAL     _         up
204.107.54.32   00.0b.fc.fe.1b.05 vlan810   VSERVER    LOCAL     _         up
204.107.54.33   00.0b.fc.fe.1b.05 vlan810   VSERVER    LOCAL     _         up
Thanks.

ACE uses the concept of Virtual Mac Addresses , which are the addresses used for VIP addresses, NAT addresses (dynamic and static), and alias addresses These will all always use a MAC address in the following form 00.0b.fc.fe.1b.
If you are using single ACE SM in a cat6k box, and you are seeing duplicate MAC, its normal. Cat6k Supervisor is L2 Adjacent with ACE, Any traffic received by Supervisor in VLAN 810 will be sent to ACE and then ACE will determine which VIP that packet is going to.
Real Problem will come when you are using multiple ACE modules in Same Chassis or you are doing Chassis to Chassis ACE Redundancy. In such situation your Cat6k Switch will have duplicate MAC entries.
To avoid this, you need to keep your Contexts in diffrent context groups in each Module i.e something like this
ft group 5
peer 1
priority X
associate-context default3
inservice

Similar Messages

Windows Network Load Balancing - Virtual MAC Address

Hi All,
I have environment that running 2 Exchange 2010 server with CASHT and join windows network load balancing as a node.
My question is,
If NLB service is restart, is it virtual MAC Address for NLB will change to new virtual MAC Address?
Thanks for response,
Best Regards,
Henry Stefanus

Hi Henry Stefanus,
The NLB work mechanism will not change whether what higher application we used and I am not very familiar with Exchange NLB architecture, may the following KB and article
may help you.
When you use the unicast method, all cluster hosts share an identical unicast MAC address. Network Load Balancing overwrites the original MAC address of the cluster adapter
with the unicast MAC address that is assigned to all the cluster hosts.
When you use the multicast method, each cluster host retains the original MAC address of the adapter. In addition to the original MAC address of the adapter, the adapter is
assigned a multicast MAC address, which is shared by all cluster hosts. The incoming client requests are sent to all cluster hosts by using the multicast MAC address.
Selecting the Unicast or Multicast Method of Distributing Incoming Requests
http://technet.microsoft.com/en-us/library/cc782694(v=ws.10).aspx
The related third party article:
Building NLB Exchange 2010 RTM CAS / HT Servers (Hyper-V) – Part 1
http://blog.morecoffeeany1.com/2010/03/19/building-nlb-exchange-2010-rtm-cas-ht-servers-hyper-v-%E2%80%93-part-1/
I’m glad to be of help to you!
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sites and has not tested any software or information found on these sites; therefore, Microsoft cannot make any representations regarding the quality, safety, or suitability of any software or information found there. There are inherent dangers in the use
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Configuring Virtual MAC Addresses on ASA

Hello,
I configure the virtual MAC address for a interface on ASA 5520, will enter the following command on the active unit:
failover mac address Inside 0012.3456.789a 0023.4567.89ab
The active MAC address is of the same as the Inside's burned-in MAC address of the active unit.
Similarly, the standby MAC address is of the same as the Inside's burned-in MAC address of the standby unit.
Do I get the effect of failover mac address command?
Thank you for your cooperation in advance.

Hi Bro
That’s fine really. There’s nothing wrong if you’ve configured the active MAC address the same as the Inside's burned-in MAC address of the active unit.
In an Active/Standby failover, the MAC addresses for the primary unit are always associated with the active IP addresses. If the secondary unit boots first and becomes active, it uses the burned-in MAC address for its interfaces. When the primary unit comes online, the secondary unit obtains the MAC addresses from the primary unit. The change can disrupt network traffic.
You can configure virtual MAC addresses for each interface to ensure that the secondary unit uses the correct MAC addresses when it is the active unit, even if it comes online before the primary unit. If you do not specify virtual MAC addresses the failover pair uses the burned-in NIC addresses as the MAC addresses.
P/S: If you think this comment is useful, please do rate them nicely :-)

NATing to the virtual MAC address of an HSRP group problems...

Hello
I have a problem where I need to NAT various IP addresses, and need the NATd addresses to carry the virtual MAC address of the HSRP group on the onward travels..
By default, with the Cisco 871's I'm using, the packets are NATd, but carry the MAC address of the external interface.. not the virtual MAC address.
The problem is that when I failover to the standby 871, the packets will then have the MAC address of the standby (new active) 871. This causes problems because my next hop doesn't update its ARP tables (very infrequent updates).
The next hop will accept packets NATd by the standby (now live), but will continue to send reply (eg ICMP) to the live (now standby) because it hasn't updated its ARP table.
I know that I can create a NAT pool with the virtual IP address as the only member of the pool. Packets will then have the virtual MAC address, and the problem will be fixed, but if I need to NAT IP addresses to *different* NATd addresses, then I would have to create multiple HSRP groups, with different virtual IP's and MAC's, and then create multiple NAT pools...
If I can't get my next hop (which I have minimal control over) to refresh/update it's ARP table, then I will consider the multiple HSRP group config, but before I try that I would like to know whether I would be able to have multiple virtual IP's and MAC's on a single interface. Apparently there was a problem with the Catalyst 2500/4500 series where the same MAC address would be used for all HSRP groups, and you had to use burned-in MAC addresses for HSRP groups.. which wouldn't provide a solution in this case..
Any ideas on how to fix this would be greatly appreciated. BTW I have proxy-arp on external interface, and gratuitous arp.
My software version is:
Cisco IOS Software, C870 Software (C870-ADVSECURITYK9-M), Version 12.3(8)YI1, RELEASE SOFTWARE (fc1)
Synched to technology version 12.3(10.3)T2
Many thanks,
Michael Blake.

Hello Michael,
you might want to have a look at the documents below, describing two techniques developed for the problem of NAT in an HSRP environement:
NAT Stateful Failover of Network Address Translation.
http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122newft/122t/122t13/ftsnat.htm
NAT Static Mapping Support with HSRP for High Availability
http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122newft/122t/122t4/ftnthsrp.htm
Regards,
GP

Virtual MAC-Address on Solaris 10 update 9

Hi,
i'm installing Solaris 10 update 9 on UCS B-Series (B230 M2 or B440 M2) with M72KR-Q Adapter. We create the Service Profile with vNIC associated to vNIC Template. The vNIC Template use the MAC Pool Address configurated.
When we run ifconfig -a on Solaris we can view only the original MAC-Address instead of Virtual MAC-Addres. Is this correct?
Thanks in advance

When you say the "original" MAC are you referring to the Hardware Default?
Ensure your MAC pool has available addresses also. You can also test unbinding the vNIC template from the Solaris service profile, and manually assigning a MAC address (watch for overlap) to the vNIC and see if that pushes to the solaris host.
If that works, then you have a pool/template issue. If not, we'll need to investigate further.
Regards,
Robert

ACE 4710 MAC Address

All physical interfaces on ACE 4710 share the same MAC address. Also, VIP addresses share the same MAC address. ACE 4710 is connected to a switch. How is the switch supposed to know which interface to send the packet to if it is doing layer2 switching.
Thank you in advance for the explanation.

You can't put 2 interfaces in the same vlan
switch/Admin(config-if)# switchport access vlan 20
vlan 20 is associated with GigabitEthernet 1/3.
switch/Admin(config-if)#
So, the L2 switch will have an entry for the mac-address in each vlan and this entry can point to different interfaces.
Gilles.

ACE multiple mac-address for a single IP (solaris ipmp)

Dear All,
We are triing to load ballance smtp traffic to solaris mail servers that are using ip multipath in bridge mode configuration.Multipath is configured so that only one of the redundant interfaces replies to arp request. Therefore all of the traffic come to the solaris from the ACE on the primary interface, but solaris uses the secondary interface too with different mac address to answer.The load ballancing working correctly it does not matter if solaris answers the request with its primary (MAC known by ACE) or secondary interface (MAC not know by ACE). But if the solaris wants to create a tcp session that is not balanced but go through the ACE with secondary interface which mac-address is not know by ARP in the ACE, the packets are silently discarded. There is no logs about it.
Please if someone could know this behavior answer.
Regards,
szicsu

If you do a 'show np 1 me-stat '-socm'' you will see a counter catching the packet drops.
Drop [mac lookup fail]: 30 0
Drop [route lookup fail]: 14316 0
We can't setup connection for unknown mac-address or if we do not have a route.
We need to first learn the mac-address through the arp request/response mechanism.
This is during this process that the encap id is associated with the mac-address.
Without that encapid we can't create the connection to flow the traffic.
You can try to disable normalization to see if that could help, but I can't guarantee it.
Gilles.

Cisco 6500 ACE ARP / mac-stick enable

Hi,
We recently found two entries on our ACE logs constantly complaining about ip/arp collisions(%ACE-4-405001), and on further investigation we saw that these IP's related to the mac addresses no longer existed anywhere in our network.
1              5              2014-06-07 06:00:03         2014-06-08 02:00:04         WARNING            LOCAL4 ACE-CORE1:         %ACE-4-405001: Received ARP RESPONSE collision from x.x.x.x yy.yy.yy.yy.yy.yy on interface vlan5
2              4              2014-06-07 10:59:48         2014-06-08 02:59:49         WARNING            LOCAL4 ACE-CORE1:         %ACE-4-405001: Received ARP RESPONSE collision from x.x.x.x yy.yy.yy.yy.yy.yy on interface vlan5
3              2              2014-06-07 06:59:48         2014-06-07 22:59:48         WARNING            LOCAL4 ACE-CORE1:         %ACE-4-405001: Received ARP RESPONSE collision from x.x.x.x yy.yy.yy.yy.yy.yy on interface vlan5
4              1              2014-06-07 10:00:04         2014-06-07 10:00:04         WARNING            LOCAL4 ACE-CORE1:         %ACE-4-405001: Received ARP RESPONSE collision from x.x.x.x yy.yy.yy.yy.yy.yy on interface vlan5
I exhausted the search for these two "ghost" ip's in our network, and finally remembered that our ACE configuration had a context we removed a few months back.
From this context we had the following configured on the interface:
interface vlan 18
description CHAT-DMZ-FW
bridge-group 1
mac-sticky enable
no shutdown
I want to confirm with you guys if anyone has seen something similar, or knows of this, but I believe the IP's learned mac addresses got "sticky" on the ACE admin context due to the mac-sticky enable command, even after we removed the context these entries persisted?
I finally used this command to remove the "ghost" IP's related to the mac addresses:
clear arp x.x.x.x no-refresh

Dear Friend,
Also confirm if the IP addresses were reachable though and as far as the Ghost synonym is referred, I can say there can be virtual mac-addresses, Ip addresses therein the network.
Thats it !
Parvesh

HSRP - Duplicate address on Vlan, sourced by mac-address

Hi ,
Network structure
Switch A --- Customer firewall 1
|
Switch B --- Customer firewall2
May be some one can help me.
There was a nagious alert yesterday and on investigation I found the 'Duplicate address x.x.x.x(VIP) on Vlanxxx, sourced by 0006.b19c.c5d9' error
It a HA feed from our switches which is going to customer firewalls.
On further investigation I have found on our switch A the ARP table is not learning the VIP address from this mac-address where as on switch B is learning the VIP address through mac 0006.b10c.c8d9 which is customer sonic firewall which is not a normal behaviour.
Our switches are Cisco 3560 switch.
Please if you could let me know what causing this.

Hi mcgowan,
Yes, there is duplicate MAC. But, its duplicate between interface vlan address and virtual MAC address on HSRP.
when I type command :
show mac address | i 0000.0c07.ac01
It shows me :
100 0000.0c07.ac01 STATIC CPU
I think this MAC generate by system on HSRP. Currently I shutdown interface vlan 100 on switch A, like as your suggestion. But the impact is my client will get trouble when switch B is down, because HSRP is not running well.
Regards,
Rakhmad

HSRP : routers respond with virtual mac AND physical mac to ARP requests

Hello.
I've noticed a very strange behaviour on my two Cisco's 2621 with HSRP configured.
But first, this is a simplified schema of my current network.
1. Summary
- IOS version : 12.2(37)
- File image : c2600-ik9o3s-mz.122-37.bin
- R1 is the active router.
- Both have tagged virtual interfaces : f0/0.10 & f0/0.60
- NAT functionnality is enabled.
     - f0/0.10 is configured as outside.
     - f0/0.60 is configured as inside.
2. Configuration samples
R1
interface FastEthernet0/0.10
encapsulation dot1Q 10
ip address 192.168.0.254 255.255.255.0
ip nat outside
service-policy output parent_out_internet
no ip mroute-cache
standby 10 ip 192.168.0.2
standby 10 priority 120
standby 10 preempt
interface FastEthernet0/0.60
encapsulation dot1Q 60
ip address 192.168.1.254 255.255.255.0
ip nat inside
no ip mroute-cache
no cdp enable
standby 60 ip 192.168.1.1
standby 60 priority 120
standby 60 preempt
ip nat pool ovrld 192.168.0.2 192.168.0.2 prefix-length 24
ip nat inside source list internet pool ovrld overload
R2
interface FastEthernet0/0.10
encapsulation dot1Q 10
ip address 192.168.0.253 255.255.255.0
ip nat outside
service-policy output parent_out_internet
no ip mroute-cache
standby 10 ip 192.168.0.2
standby 10 preempt
interface FastEthernet0/0.60
encapsulation dot1Q 60
ip address 192.168.1.253 255.255.255.0
ip nat inside
no ip mroute-cache
no cdp enable
standby 60 ip 192.168.1.1
standby 60 preempt
ip nat pool ovrld 192.168.0.2 192.168.0.2 prefix-length 24
ip nat inside source list internet pool ovrld overload
3. Events.
- When HSRP first runs or when there is a topology change, the active router sends correct ARP gratuitous reply packets (with the virtual MAC address)
- ARP table is filled in on the Internet router.
- When the ARP entry in the table expires it asks for the virtual IP mac address (192.168.0.2).
- R1 responds with the virtual MAC address ---- BUT ---- R2 also responds with its physical mac address !
- So packets are sent to the wrong router (R2) which can't route any packets because the NAT table is not up to date. I don't even have NAT command to synhronize NAT sessions between routers. But anyway, it should not solve my issue.
It occurs only on the NAT (outside) interface. On the other virtual interfaces it behaves as expected.
I don't have any explanations to this behaviour.
For the moment, I have to keep R2 offline and bring it back online in case of failure.
I tried several workarounds but I can neither filter ARP packets (no such function) on my router nor on my switch (too restrictive).
If I forgot any information please ask me.
Any help would be very much appreciated.

Hello.
I've noticed a very strange behaviour on my two Cisco's 2621 with HSRP configured.
But first, this is a simplified schema of my current network.
1. Summary
- IOS version : 12.2(37)
- File image : c2600-ik9o3s-mz.122-37.bin
- R1 is the active router.
- Both have tagged virtual interfaces : f0/0.10 & f0/0.60
- NAT functionnality is enabled.
     - f0/0.10 is configured as outside.
     - f0/0.60 is configured as inside.
2. Configuration samples
R1
interface FastEthernet0/0.10
encapsulation dot1Q 10
ip address 192.168.0.254 255.255.255.0
ip nat outside
service-policy output parent_out_internet
no ip mroute-cache
standby 10 ip 192.168.0.2
standby 10 priority 120
standby 10 preempt
interface FastEthernet0/0.60
encapsulation dot1Q 60
ip address 192.168.1.254 255.255.255.0
ip nat inside
no ip mroute-cache
no cdp enable
standby 60 ip 192.168.1.1
standby 60 priority 120
standby 60 preempt
ip nat pool ovrld 192.168.0.2 192.168.0.2 prefix-length 24
ip nat inside source list internet pool ovrld overload
R2
interface FastEthernet0/0.10
encapsulation dot1Q 10
ip address 192.168.0.253 255.255.255.0
ip nat outside
service-policy output parent_out_internet
no ip mroute-cache
standby 10 ip 192.168.0.2
standby 10 preempt
interface FastEthernet0/0.60
encapsulation dot1Q 60
ip address 192.168.1.253 255.255.255.0
ip nat inside
no ip mroute-cache
no cdp enable
standby 60 ip 192.168.1.1
standby 60 preempt
ip nat pool ovrld 192.168.0.2 192.168.0.2 prefix-length 24
ip nat inside source list internet pool ovrld overload
3. Events.
- When HSRP first runs or when there is a topology change, the active router sends correct ARP gratuitous reply packets (with the virtual MAC address)
- ARP table is filled in on the Internet router.
- When the ARP entry in the table expires it asks for the virtual IP mac address (192.168.0.2).
- R1 responds with the virtual MAC address ---- BUT ---- R2 also responds with its physical mac address !
- So packets are sent to the wrong router (R2) which can't route any packets because the NAT table is not up to date. I don't even have NAT command to synhronize NAT sessions between routers. But anyway, it should not solve my issue.
It occurs only on the NAT (outside) interface. On the other virtual interfaces it behaves as expected.
I don't have any explanations to this behaviour.
For the moment, I have to keep R2 offline and bring it back online in case of failure.
I tried several workarounds but I can neither filter ARP packets (no such function) on my router nor on my switch (too restrictive).
If I forgot any information please ask me.
Any help would be very much appreciated.

Why "mac-address-table static 0000.0c07.ac01 interface FastEthernet1/0 vlan 3" in the router ?

Hi All
I did not type the following command. Why does it appear when I show run ? Which command can cause the issue? Thank you
mac-address-table static 0000.0c07.ac01 interface FastEthernet1/0 vlan 3

Hello,
It looks as if you have HSRP configured. Mac address 0000.0c07.ac01 is the HSRP virtual mac address. 01 at the end of the mac represents the HSRP group number.
Hope this helps,
Please rate helpful answers.
Thanks.

VRRP MAC address

Please tell me what MAC address VRRP uses for the virtual IP. Do all cisco IOS use only one unique MAC for one VRRP group? What about the virtual MAC address in case master failure, does new master(previously backup) still use same virtual MAC after previous master fails?
Also I want to know if it is possible that IOS answer ARP request for the virtual IP with master's real physical MAC address in some cases.
For example, R1 e0 is configed with VRRP, its physical MAC address is MAC-PHY, virtual MAC for that virtual ip is MAC-VIR. When ping the virtual IP, master R1 answer ARP with MAC-PHY, or other MAC than MAC-VIR. Is that possible in some cases?
I used 2610 and 3610 IOS 12.3 test it. And I found it always use same virtual MAC. But I am not sure different platform/IOS has different beheavior.
Thanks in advance.

Please tell me what MAC address VRRP uses for the virtual IP. Do all cisco IOS use only one unique MAC for one VRRP group?
>>>The virtual router MAC address associated with a virtual router is an IEEE 802 MAC Address in the following format:
00-00-5E-00-01-{VRID} (in hex in internet standard bit-order)
The first three octets are derived from the IANA's OUI. The next two octets (00-01) indicate the address block assigned to the VRRP protocol. {VRID} is the VRRP Virtual Router Identifier. This
mapping provides for up to 255 VRRP routers on a network.
What about the virtual MAC address in case master failure, does new master(previously backup) still use same virtual MAC after previous master fails?
>>> Yes, per above that mac-address is associated to Virtual Router.
Also I want to know if it is possible that IOS answer ARP request for the virtual IP with master's real physical MAC address in some cases.
For example, R1 e0 is configed with VRRP, its physical MAC address is MAC-PHY, virtual MAC for that virtual ip is MAC-VIR. When ping the virtual IP, master R1 answer ARP with MAC-PHY, or other MAC than MAC-VIR. Is that possible in some cases?
>>> I don;t think so since there is no interface command to tell router to use BIA for VRRP much like the HSRP.
I used 2610 and 3610 IOS 12.3 test it. And I found it always use same virtual MAC. But I am not sure different platform/IOS has different beheavior.
>>> It's not platform dependent it's how it operate per RFC 2338.
Please rate helpful posts.

Understanding Wireless Mac Address

Hi,
I would like to know te range of mac address used for only Cisco Wireless, and I would appreciate to know how the ap and the controler assign the virtual mac address they use and how to get them from the WLC gui.
WLC - 4400
AP - Air1131
Thanks

As you add SSIDs (Service Set Identification(s)) to an access point each BSSID (Basic Service Set Identifier) receives a virtual mac address. This allows for wireless network segmentation as well as for wireless clients to communicate via LAYER 2 with each access point BSSID.
A Cisco access point takes the base radio mac address and then virtualizes the mac address as additional SSIDs are added. What is interesting is how the virtual MAC addresses are selected. Pay very close attention to the 2.4GHz and 5 GHz radios and BSSIDs.
BASE RADIO MAC ADDRESS
You can find the base radio mac address under WIRELESS->Select Access Point
Virtualized BSSID(s)
I configured a controller with 16 SSIDs. Each SSID named as 01,02,03,04,05,06, 07,08,09,10,11,12,13,14,15 and 16. I then enabled both the 2.4 GHz and 5 GHz radios. Cisco WLC access points have a limit of 16 SSIDs on each radio.
I then fired up AirMagnet WiFi Analyzer Pro to conduct a capture.
Note: The access point base radio mac address ends in A9:10.
2.4 GHz – Notice the first SSID ‘01’ is assigned the BASE RADIO MAC ADDRESS A9:10. The second SSID is appended with a .11 and so on.
5GHz – Notice the sixteenth SSID ‘16’ is assigned the BASE RADIO MAC ADDRESS A9:10. The fifteenth SSID is appended with a .11 and so on.
NOTE: The VIRTUAL MAC ADDRESSES get reused by the access point on both the 2.4GHz and the 5GHz radios.
Virtualized BSSID Assignment
Keep in mind, the assignment or order in which the virtual mac addresses are assigned in the above example has nothing to do with the WLAN IDs that are configured in the WLC. Rather, the virtual mac addresses are assigned in order by how the SSID is assigned to the access point.

Help required - mac address table, virtual pc/ip addressing issue

Hi, hope someone out there can help?
This is the scenario
SW1 (WS-C2960G-48TC-L) port gig0/1 has a PC connected to it with ip address 10.182.8.6 and a Virtual IP address 10.182.8.107
SW2 (WS-C2960-24TT-L) port gig 0/1 has a PC connected to it with ip address 10.182.8.106
The system is designed so that if there is an issue with the PC connected to SW1, the PC on SW2 will take over the Virtual IP address and continue working.
We have a couple of other PC's in different subnets to the above PC's that use the Virtual IP (VIP) address to communicate with the PC that is 'on line'.
Unfortunately, the vendors software doesn't currently gratuitously refresh the arp to advertise the change of mac address for the VIP.
Is there anyway we can get the 2 dcnsw to 'refresh' on a regular time period to capture when the VIP changes to the other PC?

Hi Stephen
Without meaning to sound rude, the software which uses a VIP is not very well designed if it is not capable of sending a Gratuitous ARP one the Active one fails.
The default ARP cache timeout is 4 hours so an ARP entry will remain in the table and once the timeout is up, the switch will send an ARP to check if the device is still alive and if not, remove the entry from the table.
You could look at reducing the ARP timeout on a per port basis:
#interface gi1/0/1
#arp timeout 60
This will change the ARP cache timeout to 60 seconds for that port but having not used this before, I am not 100% this will address your issue. I would not advise trying to change the global ARP cache timeout for a production switch as this will increase ARP traffic and could cause problems if reduced to a small value.

ACE How can we do a static arp to multicast mac address?

I have a architecture that uses ACE to do Firewall Load Balancing. I need to add a static map of a VIP IP to a multicast mac address (Microsoft servers with NLB in multicast mode). The ACE does not accept multicast mac address in the static arp statement, anybody knows why? Is there any other way to do that?
Regards,
Artur Pinto

Hi,
The ACE doesn't support multicast MAC addresses. This is a limitation impose by the hardware used on the boards. Syed has previously proposed a workaround at https://supportforums.cisco.com/message/464174#464174 . I don't know if that will be applicable in your case.
HTH
Cathy

ACE virtual mac address allocation

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