Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Announcements

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. If you'd prefer to explore, try our test area to get started. And see here for current known issues.

New Member

ip device tracking probe delay

 

Hi,

 "'ip device tracking probe delay 10 "" , will it means that ,  normally   cisco device (switch or router or firewall) automatically generate the ARP and if this command given it delays for 10 sec ? or it will delay the the unknown flooding for 10 sec ?

Everyone's tags (1)
3 REPLIES

Hi Jithu, It actually delay

Hi Jithu,

 

It actually delay the proble from switch or router for 10 seconds during that time Windows server can sort out the duplicate ip issue detection.

Explanation from Cisco Site:

ip device tracking probe delay 10

The RFC specifies a ten−second window for duplicate address detection, so if you delay the
device−tracking probe, it resolves the issue in nearly all cases. In addition to probe−delay, the delay
also resets when the switch detects a probe from the PC. For example, if the probe timer has counted
down to five seconds and detects an ARP Probe from the PC, the timer resets back to ten seconds. In
rare circumstances, the PC sends an ARP Probe milliseconds before the switch sends its probe, which
still triggers a duplicate address message to the end user. This command was introduced in Version
15.0(1)SE on 2900, 3500, and 3700 Series switch platforms, Version 15.0(2)SG on the 4500 Series
switch platform, and Version 12.2(33)SXI7 on the 6500 Series switch platform.
 
HTH
 
Regards
Karthik
 
New Member

  Thanks Karthik , From where

 

 

Thanks Karthik ,

 From where the switch gets arp probes , will it automatically generate ? , i know switch will send gratuitous arp if HSRP is enabled , if hasrp is disabled why the switch sends arp until and unless an unknown unicast ocure , please help....

 

Hi Jithu, All i understand

Hi Jithu,

 

All i understand from my above post and RFC for arp probes and gratuitous arp..... if a hosts gets a duplication of address for example say 2 hosts announces that it has the ip address x.x.x.x.... since the arp reply happens unicast other host will not come to know the conflict..... for that there is a workaround to have the arp reply/ack also should happen broadcast..... in such cases delay of 10 sec to probe the hosts.... the hosts will get the conflict of IP address corrected.... So duplication issue and blockage is avoided.

http://www.itcertnotes.com/2011/08/windows-xp-and-windows-7-gratuitous.html

Refer RFC 5227 & 826 for better understanding.

 

HTH

 

Regards

Karthik

 

4021
Views
0
Helpful
3
Replies