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Could this be due to a possible loop in teh network

Nexus1# sh ip arp 10.63.57.27    -  ( Where this IP Address belongs to a Server in a HP C7000 Blade Enclosure with HP Virtual Connect modules installed).


IP ARP Table
Total number of entries: 1

Address         Age       MAC Address     Interface

10.63.57.27     00:00:02  8622.33e2.ea0d  Vlan57

SBC_NX7010_1-Service# sh mac address-table address 8622.33e2.ea0d
Legend:

        * - primary entry,
        G - Gateway MAC, (R) - Routed MAC
       
        age - seconds since last seen,
        + - primary entry using vPC Peer-Link
 

VLAN     MAC Address      Type      age     Secure NTFY    Ports

---------+-----------------+--------+---------+------+----+------------------

* 56       8622.33e2.ea0d    dynamic   0          F    F  Eth1/3 (False)

* 57       8622.33e2.ea0d    dynamic   0          F    F  Eth1/1 (True)

Please explain teh False and True above. Does it mean this MAc address was seen on Eth1/3 but later was seen on Eth1/1

Could this be due to a possible loop in the network that this MAC address is flapping?

The above commands were done on a Cisco Nexus 7010 switch which is connected to HP Virtual Connect Modules installed in HP Blade Enclosures.

Everyone's tags (2)
4 REPLIES
New Member

Re: Could this be due to a possible loop in teh network

On Eth1/1 and Eth1/3 connecting the Nexus 7010 to HP's Virtual Connects teh following command is present:

"spanning-tree bpdufilter enable"

Should this command be removed?

Re: Could this be due to a possible loop in teh network

You dont need to remove bpdufilter... it protects the port from unwanted bpdu anyways... what constitutes vlan 56 & 57 ? are these layer 2 or layer 3 vlans ? even if you have teaming configured, why would you have both these ports on different vlans ?

Raj

Re: Could this be due to a possible loop in teh network

Nexus1# sh ip arp 10.63.57.27   -  ( Where this IP Address belongs to a Server in a HP C7000 Blade Enclosure with HP Virtual Connect modules installed).


IP ARP Table
Total number of entries: 1

Address         Age       MAC Address     Interface

10.63.57.27     00:00:02  8622.33e2.ea0d  Vlan57

SBC_NX7010_1-Service# sh mac address-table address 8622.33e2.ea0d
Legend:

        * - primary entry,
        G - Gateway MAC, (R) - Routed MAC
       
        age - seconds since last seen,
        + - primary entry using vPC Peer-Link

VLAN     MAC Address      Type      age     Secure NTFY    Ports

---------+-----------------+--------+---------+------+----+------------------

* 56       8622.33e2.ea0d    dynamic   0          F    F  Eth1/3 (False)

* 57       8622.33e2.ea0d    dynamic   0          F    F  Eth1/1 (True)

Please explain teh False and True above. Does it mean this MAc address was seen on Eth1/3 but later was seen on Eth1/1

Could this be due to a possible loop in the network that this MAC address is flapping?

The above commands were done on a Cisco Nexus 7010 switch which is connected to HP Virtual Connect Modules installed in HP Blade Enclosures.

Hi ,

Is your server is connected with both the ports and are having teaming configured at server end,If yes then it can be problem at server end that ports ate server end would be flapping.

Hope to help

Ganesh.H

Hall of Fame Super Silver

Re: Could this be due to a possible loop in teh network

Hello Alphonse,

some servers choice to use a single MAC address as source out multiple NICs, in your case using the same MAC address in different vlans is not a problem CAM is organized using Vlan, MAC address, port.

I see the same in some cases it is not a problem by itself until you don't see MAC address flapping messages in device log

Hope to help

Giuseppe

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