default gateway

Unanswered Question
May 1st, 2007
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We have 4500 switch running layer 3 IOS and eigrp. It has one

user VLAN. Users on that vlan can set their default gateway to any router on

our network and it works. I am curious why this is working ? I thought you

always need to set default gateway to be as swith vlan interface for the end

users.


chasis : 4506

Sup IV WS-4515

IOS: cat4000-i5k9ls-mz.122-25.EWA6.bin


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dgahm Tue, 05/01/2007 - 07:17
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That is called proxy ARP. When the router hears an ARP request for an address on a different subnet that it knows how to reach it will respond with its MAC address.


It is still a good idea to use the correct default gateway as someone might disable proxy arp on the interface.


http://www.cisco.com/en/US/tech/tk648/tk361/technologies_tech_note09186a0080094adb.shtml


Please rate helpful posts.


Dave

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