Adam75
asked on
Wireless & ARP issue
Switch: Dell PowerConnect 2848
Wireless AP: Cisco 1140 Series
Laptops: Dell E6510,E6400 running Win7 Enterprise
Symptom: Devices connected via wireless fail to ping machines that are hard wired for generally 5 attempts, and then work perfectly. Doing a ping -t will show near perfect results (0% loss) for hours after the initial failures.
Wired devices fail to EVER ping a wireless device with "destination host unreachable" UNLESS I ping it with the wireless device first. Basically the wired devices are unable to ARP for a wireless device.
If I ping with the wireless device, it gets added to the arp table on the wired device, and then the wired can ping the wireless. If I delete the arp table entry from the wired device, it goes back to "destination host unreachable".
I have replicated this on W2K8 and Ubuntu Linux wired servers, and multiple Win7 laptops connected wirelessly. If I disable the wireless NIC, and hard wire the laptops, everything is fine.
Client ARP caching is set to disabled on the Cisco AP's.
Wireless AP: Cisco 1140 Series
Laptops: Dell E6510,E6400 running Win7 Enterprise
Symptom: Devices connected via wireless fail to ping machines that are hard wired for generally 5 attempts, and then work perfectly. Doing a ping -t will show near perfect results (0% loss) for hours after the initial failures.
Wired devices fail to EVER ping a wireless device with "destination host unreachable" UNLESS I ping it with the wireless device first. Basically the wired devices are unable to ARP for a wireless device.
If I ping with the wireless device, it gets added to the arp table on the wired device, and then the wired can ping the wireless. If I delete the arp table entry from the wired device, it goes back to "destination host unreachable".
I have replicated this on W2K8 and Ubuntu Linux wired servers, and multiple Win7 laptops connected wirelessly. If I disable the wireless NIC, and hard wire the laptops, everything is fine.
Client ARP caching is set to disabled on the Cisco AP's.
ASKER
Product/Model Number: AIR-AP1142N-A-K9
System Software Filename: c1140-k9w7-tar.124-21a.JA1
System Software Version: 12.4(21a)JA1
Bootloader Version: 12.4(18a)JA3
System Software Filename: c1140-k9w7-tar.124-21a.JA1
System Software Version: 12.4(21a)JA1
Bootloader Version: 12.4(18a)JA3
1 Clear arp cache on the router
2 Check speed/duplex settings on all interfaces
3 Make sure that you permit imcp echo-reply to come back in.
access-list PING permit icmp any any eq echo-reply
access-group PING in interface outside
4 Check if you have Ap isolation on - should be off
http://homecommunity.cisco.com/t5/Wireless-Routers/AP-isolation/td-p/23327
2 Check speed/duplex settings on all interfaces
3 Make sure that you permit imcp echo-reply to come back in.
access-list PING permit icmp any any eq echo-reply
access-group PING in interface outside
4 Check if you have Ap isolation on - should be off
http://homecommunity.cisco.com/t5/Wireless-Routers/AP-isolation/td-p/23327
If you temporarily replace the Dell with an unmanaged 16 or 24 port switch, does the same ARP [mis]behavior continue?
If not, that would point to a setting in the 2848 causing the lag on the ICMP responses in just the one direction.
If not, that would point to a setting in the 2848 causing the lag on the ICMP responses in just the one direction.
ASKER CERTIFIED SOLUTION
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well done:)
ASKER
When nothing makes sense, start over...
http://www.cisco.com/en/US/prod/collateral/wireless/ps5678/ps6087/product_bulletin_c25-560118_ps10092_Products_Bulletin.html
JAN MA CCNA