Wrong mac address from stack SG500?

[LoDo]

Hi,

It's my connection scheme.

There is a routing problem between vlans if one of the devices connected to the unit 2.

Within the same vlan devices are available for each other.

If PC200 connected to Gi1/1/15

Sniff ICMP traffic on Gi1/1/15:

Icmp request from 192.168.112.1 to 192.168.101.200:

Src: 24:01:c7:08:02:49 (192.168.101.254),

Dst: b8:88:e3:0e:1a:da (192.168.101.200)

  Icmp replly from 192.168.101.200 to 192.168.112.1:

Src: b8:88:e3:0e:1a:da (192.168.101.200)

Dst: 24:01:c7:08:02:49 (192.168.101.254)

If PC200 connected to Gi2/1/15

Sniff ICMP traffic on Gi2/1/15:

Icmp request from 192.168.112.1 to 192.168.101.200:

Src: 24:01:c7:08:00:01 (192.168.101.254),

Dst: b8:88:e3:0e:1a:da (192.168.101.200)

Icmp replly from 192.168.101.200 to 192.168.112.1:

Src: b8:88:e3:0e:1a:da (192.168.101.200)

Dst: 24:01:c7:08:00:01 (192.168.101.254)

Where does this mac-address (24:01:c7:08:00:01) appear? In the arp table on PC200 it is none.

[Tom Watts]

Well, I'm guess you may be seeing a port MAC address.

Are you on the newest firmware?

-Tom
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[LoDo]

Firmware version 1.3.5.58.

This address (24:01:c7:08:00:01) it is not in the mac-address table.

swcore#sh mac address-table address 24:01:c7:08:00:01

Aging time is 300 sec

  Vlan        Mac Address         Port       Type

-------- --------------------- ---------- ----------

swcore#sh mac address-table address 24:01:c7:08:02:49

Aging time is 300 sec

  Vlan        Mac Address         Port       Type

-------- --------------------- ---------- ----------

   1       24:01:c7:08:02:49       0         self 

[LoDo]

Hi,

With firmware 1.3.0.62 the same problem.

If the interface Gi2/1/15 to down and up - the first two icmp request has a source MAC

24:01:c7:08:02:49, remaining request has a source MAC 24:01:c7:08:00:01.

#show stack

Unit Model Name     MAC Address       Software  Master   Unit No./       Status       Mode After Reboot

---- -------------- ----------------- --------- -------- --------------- ------

1    SG500-28       24:01:c7:08:02:49   1.3.0.62  Enabled         1,            master              Native

2    SG500-28       24:01:c7:08:02:2c   1.3.0.62  Enabled         2,            backup              Native                  

[Tom Watts]

And I suspect from within the same VLAN the issue is not present. That would suggest the switch is incorrectly using the port MAC instead of the system MAC.

-Tom
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[LoDo]

Yes, within one vlan such problems aren't present. In this case, the source mac address - real mac address of the computer from which icmp requests are sent.

If to ping from the switch, source mac address is 24:01:c7:08:02:49.

The mac address 24:01:c7:08:00:01appears if the icmp request is routed on the switch. Such situation for any port of  the stack unit 2.

[LoDo]

Somebody has any ideas how to fix it?

[Tom Watts · Accepted solution]

Lodo, I believe this is a bug. Best I'd recommend is call the SBSC and make a case. I believe it is related to bug

CSCub82382

-Tom
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[danielj80]

I'm running into the same (or very similar) problem. The bug report Tom put up is locked. I'm going to give SBSC a ring, and see if they have a update.

[LoDo]

TAC confirmed this bug. Fix will be in the next firmware version.
Today I received a beta version, but have not tested it yet.

[mpyhala]

All,

Firmware version 1.3.7.18 was released today.

- Marty

[danielj80]

Yay :-)

Out of curiosity, is this the same as CSCub82382, or was that already fixed in a previous firmware? The bug report is restricted, so I can't see it myself.

[mpyhala]

danielj80,

CSCub82382: SG500 - device is malforming packets It appears that this was resolved in a previous firmware.

- Marty

Message was edited by: Martin Pyhala

[danielj80]

Someone official may want to update

https://supportforums.cisco.com/thread/2141121 as it seems to be very similar, and this firmware may help some thread followers.

[danielj80]

I just put the firmware on, but it didn't resolve my problem (MAC address announcements hopping between ports). I noticed the firmware release notes didn't claim to correct any defects. Is this bug corrected in today's firmware, or slated for a later one?