Cisco 1841 with HWIC-4ESW - ARP Problem

[mshabani363]

hi 

i have installed an HWIC-4ESW on a cisco 1841 router and attached an ADSL modem to one of its ports. (f0/0/0)

i have created a vlan and put the interface on that vlan and assigned an ip address to the interface vlan.

now i can ping the ADSL modem.

then i add a route :

ip route 8.8.8.8 255.255.255.255 <ADSL_IP>

now i can ping 8.8.8.8

but the problem is when the router is idle for some time. after that i can not ping the 8.8.8.8 and the connection is lost.

when i do "clear arp-cache" then the connection is OK again.

this problem caused my tunnels goes down after a while and the communication is lost.

is there any idea about this problem ?

[Mark Malone]

Hi I had a problem like this with an edge router before , used ip sla to keep the communication alive so every 5 seconds a ping was sent to 8.8.8.8 and 8.8.4.4 from our source ip on the router and this kept our circuit up , the issue after using a wireshark was the communication between some local ISP modem and 1 of our cisco 881s kept timing out even after firmware upgrades

may help for your setup

example

ip sla 1
 path-echo 8.8.8.8 source-ip 1.1.1.1
 frequency 5
ip sla schedule 1 life forever start-time now