Apple Devices Casuing intermittent network outages

[Thomas_Randolph]

We have recently started rolling Apple devices at one of our locations. Approximately 1200 iPads. They are connecting to via an Aerohive wireless solution. That solution has 1 point of entry to my network at a B5 switch that is also doing layer 3 for that site to our WAN. When the iPads starting ramping up, it has seemed to cause frequent intermittent network outages. Devices on the rest of lan in different vlans stop communicating and then will come back within 5-10 seconds. This happens anywhere from 1-50 minutes during every hour of the day including overnight when no users are onsite. After extensive troubleshooting, we still have not identified the cause of the problem but believe it is possibly something with the B5G124-48P2. From one of my switches at the local site, when the problem happens, I cannot reach my default gateway, which is the IP address of that vlan interface configured on the B5. Since affects all vlans, we suspect the B5. The routing is all static and RIP is disabled. Also when this is happening, the system CPU is not excessive, it is usually around 26-45% but I have seen it spike very shortly up to 60-80%. I have debug logging enable and the have no logs indicating that system resources are taxed. The only recurring log entry I get is "DHCPRELAY[265701448]: relay_main.c(315) 568089 This is from manager 1 %% Request could not be relayed to Server". I have also checked my DHCP server, however it is supporting all 14 of my sites with no issues anywhere else. I checked the mac tables and we usually sit at just under 4000 entries, but according to the specs for the B5 it can support up to 24,000. I appreciate any help or suggestions.

[Jason_Parker]

Another thought What mgbic are you using Try Set. Logging local Consol enable file enable Set logging default severity 7 Remove and insert the mgbic any messages in the show logging buffer How about egress Show vlan port info port port# Also try it on the uplink to dhcp and radius server

[Arison_Mercado]

Hi Thomas,

Any luck on this? I've been battling this for over a year and it seems to get worse and worse. And Yes, I do have random clients that connect to the wireless but cannot reach their gateway and that doesn't just happen on Apple devices.

[Thomas_Randolph]

Current update. We found out that for some reason the Layer 3 ARP Cache is not holding records. For example, the default ARP Cache is 4 hours. We have network switches that are showing anywhere from 0-5 minutes age on their ARP entries. No ARP Entry is past 10 minutes for anything. Also when an entry drops out of the list, it can take from a few seconds up to hour to re-populate. The number of entries in the cache is just over 2000 so not even close to the max. Same thing with mac address tables. We are waiting for a replacement device from Extreme support to see if that fixes the issue.

[Thomas_Randolph]

The ports we are using are copper Ethernet. No gbics involved