Hi all,

I have two cisco routers and one windows server. All is connected to the
catalyst 4006 (L3 Router) :

ROUTER_A
SERVER_A
ROUTER_Z
SWITCH_4006

When SERVER_A need to talk with ROUTER_A via SWITCH_4006. The SWITCH_4006
receive ARP response from ROUTER_Z talking that the MAC address of SERVER_A
is his MAC address !!! why !!???

I confirme that each network interface has it MAC address !!

So, bad mac address is allocated on the SWITCH_4006.
On the same time, i can see on the SWITCH_4006 the real MAC address of
ROUTER_Z !!

So, this problem cause packet lost between SERVER_A and ROUTER_A

Can you help me please !!???

ThankYou very mych.

Best Regards
NS

"ns" <ns@none.ns> wrote in message news:38oqicF5q80dgU1@individual.net...
Typically, this happens when the subnet mask is set incorrect on the router
inteface, or there are mismatched secondary addresses. A router will
respond with its MAC address in proxy for an IP address. If it receives an
ARP request for a device on another interface, it will answer that ARP in
order to facilitate routing.

You can turn it off:

interface (mumble)
no ip proxy-arp

But, if the reply is happening, you probably have some kind of address/mask
mixup, or an interface plugged into the wrong LAN or VLAN.


Need more details, like configuration....

Hi all,

- The subnet mask is correct

- I don't have secondary address on the router but i have two FastEthernet
interfaces. The router is used as gateways between two physical networks.

I will try the command "no ip proxy-arp" on the interface but i don't
understund why the router is identified as owner of mac address searched !

ThankYou very much Phillip for your help
I will let you know a bout tests.

Best Regards
NS


"Phillip Remaker" <rekamerpillihp-usenet1@yahoo.com> a écrit dans le message
de news:%dIVd.2309$C47.926@newssvr14.news.prodigy.com ...