If you have an arp entry for a corresponding IP address that hasn't existed for a year, something is keeping it in the cache. Could the timeout value be set to never time out? I see in your output the timeout value is set for a couple hours so easy to dismiss the thought, but is this for every interface? I know in router arp caches, you can set the timeout value different for each interface at interface command mode, but in show arp-cache at exec priv level, these differences in timeout are not noted. You got to look deeper in the router to see this. I don't know about set based comparison in this regard.
> -----Original Message----- > From: [EMAIL PROTECTED] [mailto:nobody@;groupstudy.com]On Behalf Of > Keith Woodworth > Sent: Friday, November 01, 2002 12:55 PM > To: [EMAIL PROTECTED] > Subject: Clearing ARP. [7:56651] > > > We have a Cat5500 with an odd problem. There is a customer with a Vlan > setup on 2 RSM's using HSRP. The Vlan is using a /29, with each RSM > assigned an IP from the /29, a default gateway from the /29 > which leaves > 3 usable IP's for the customer. > > He has 2 devices plugged into 2 ethernet ports on the > Cat5500, a Redback > and a 3640, each has an IP from the /29, leaving one more to > use. He wants > to add a switch, so config the switch to use the last IP from the /29, > assign the port to the Vlan and the switch should be accessable. > > I'm telnetted to the console of the switch and I can ping the > 3640 and the > Redback ok, but not the switch. A ping to the customers > switch wants to go > out an IP on an interface that does not exist and has not > existed for a > looong while. > > A show arp below shows two entries on the same port/vlan. > 204.244.98.19 > should not be there. I'd like to do a clear ARP on the > console so that it > will remove the old entry but should it have not removed it by now? We > changed things over over year ago taking out the 98.19 address. > > My question though lies in what affect clearing the ARP table on the > console will have on overall routing? Its just on the console of a > Catalyst 5500, not on the RSM's. 64.114.55.67 is the gateway for Vlan1 > which is the management Vlan for the RSM's. > > How quick does the ARP table get repopulated? > > Cisco 5500> (enable) sh arp > ARP Aging time = 1200 sec > 64.114.55.67 at > 00-00-0c-07-ac-01 port 3/1 on > vlan 1 > 204.244.98.19 at > 00-00-0c-07-ac-01 port 3/1 on > vlan 1 > > Thanks, > Keith Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=56676&t=56651 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
