Local Area Mobility with redundant Routers

Unanswered Question
Sep 17th, 2008

Hi,I wantto use LAM (Local Area Mobility)

in my network to make it possible that the can use Hosts with static IP-Addresses on different places in the network.

Has anybody experience with LAM on sites with redundant Routers. (topology on every site:2 redundant Routers running HSRP(not for LAM) an one L2-Switch where routers and Hosts are connected)

If the former active router fails the Mobile Host in the local Network does not recognize this and is in my opinion not able to communicate via the Router until he did again an ARP-Request for its default-GW and the now active Router answers this request with proxy-ARP.

This can need a lot of time, depending of the arp-cache timeout of the host.

Any ideahow to prevent this ?

Kind Regards


I have this problem too.
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HUBERT RESCH Sun, 11/16/2008 - 22:07

ne Hannes , leider nicht, andre Frage hast du schon mal mulilink-multichassis ppp konfiguriert für die Verbindung von 2 Standorten mit redundanten Routern ? geht das ?

Johann Frey Mon, 11/17/2008 - 12:28

hab ich noch nicht gebraucht. ob das geht ist eine gute frage? hast hier nichts dazu gefunden?

Mohamed Sobair Mon, 11/17/2008 - 23:00

Hi Hubert,

Have you decreased (Mobile ARP timers keepalive)?

The mobile ARP entries can be configured to time out more quickly. The LAM feature allows for the configuration

of a keepalive time and a hold time for mobile ARP entries on an interface. When using LAM, a router periodically checks

to ensure that the mobile host is still there by querying it with ARP requests. This ensures that the redistributed route

is still valid. The mobile host ARP keepalive times can be altered with the command:

ip mobile arp timers [keepalive minutes] [hold-time minutes]

Please refer to the bellow link for further details:





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