[c-nsp] Cisco 2970 Switch v Microsoft NLB

[Devon True]

All:

I have an issue where a Cisco 2970 switch will not add a dynamic MAC
address for a NLB IP address in its mac-address-table. The NLB MAC
address is 02bf.0a00.0273.

Any packets destined for the NLB MAC address gets broadcasted out all
ports (I used Ethereal to capture the traffic) causing unnecessary
network traffic. I resolved the problem by adding a static
mac-address-table entry on the 2970 switch.

	mac-address-table static 02bf.0a00.0273 vlan 1 interface GigabitEthernet0/3

I also read the previous cisco-nsp thread about this issue but it
concerned Cisco routers and not switches. I assume this may be general
IOS behavior? The upstream device from the switch is a Cisco PIX that
has static(inside,outside) commands to MAP the external/internal IP
addresses. The PIX does not seem to have the same issue since there are
not static ARP entries configured.

Previous cisco-nsp thread:
<http://thread.gmane.org/gmane.network.nsp.cisco/25944/focus=26034>

Has anyone seen this issue before? I can remove the static
mac-address-table entry and the site still works, but there is a
mini-broadcast storm out every port.

--- show version ---

Cisco Internetwork Operating System Software
IOS (tm) C2970 Software (C2970-I6L2-M), Version 12.1(19)EA1d, RELEASE
SOFTWARE (fc1)
Copyright (c) 1986-2004 by cisco Systems, Inc.
Compiled Mon 05-Apr-04 20:42 by antonino
Image text-base: 0x00003000, data-base: 0x006A5954

ROM: Bootstrap program is C2970 boot loader
BOOTLDR: C2970 Boot Loader (C2970-HBOOT-M) Version 12.1(14r)EA1a,
RELEASE SOFTWA
RE (fc1)

tp-prod-sw1 uptime is 1 hour, 59 minutes
System returned to ROM by power-on
System image file is
"flash:c2970-i6l2-mz.121-19.EA1d/c2970-i6l2-mz.121-19.EA1d.bin"

cisco WS-C2970G-24TS-E (PowerPC405) processor (revision E0) with
118776K/12288K
bytes of memory.
Processor board ID CSG0836P0SP
Last reset from power-on
1 Virtual Ethernet/IEEE 802.3  interface(s)
28 Gigabit Ethernet/IEEE 802.3 interface(s)
The password-recovery mechanism is enabled.

512K bytes of flash-simulated non-volatile configuration memory.
Base ethernet MAC Address       : 00:12:01:0A:81:80
Motherboard assembly number     : 73-9095-04
Power supply part number        : 341-0045-01
Motherboard serial number       : CAT083602U8
Power supply serial number      : LIT083207DB
Model revision number           : E0
Motherboard revision number     : A0
Model number                    : WS-C2970G-24TS-E
System serial number            : CSG0836P0SP
Top Assembly Part Number        : 800-24261-01
Top Assembly Revision Number    : F0
Hardware Board Revision Number  : 0x02


Switch   Ports  Model              SW Version              SW Image
------   -----  -----              ----------              ----------
*    1   28     WS-C2970G-24TS-E   12.1(19)EA1d            C2970-I6L2-M


Configuration register is 0xF

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

Thanks,

Devon