ARP LIMIT C5210

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  • Updated 3 years ago
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Controller C5220 have a message:

ERRO: Dynamic ARP entries exceed the MAX limit: 4096
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Luis Mendes

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Posted 3 years ago

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Doug Hyde, Technical Support Manager

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Luis Mendes

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Other message is:

TCP: Possible SYN flooding on port 13013. Dropping request.


Whit command

  netstat -tuna |grep "SYN_RECV"

All traffic has redirect to address 172.31.0.17 and this address has an interface TAP0

tap0      Link encap:Ethernet  HWaddr 00:11:22:33:44:55          inet addr:172.31.0.17  Bcast:172.31.0.31  Mask:255.255.255.240
          UP BROADCAST RUNNING NOARP MULTICAST  MTU:1500  Metric:1
          RX packets:228210597 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:500
          RX bytes:3307952554 (3.0 GiB)  TX bytes:0 (0.0 b)
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Doug Hyde, Technical Support Manager

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I'm not sure the code track would matter, it may depend on when the issue is triggered. You should contact the GTAC so someone can investigate this further. When these messages occur it's usually network traffic related not controller or firmware specific.  
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Doug Hyde, Technical Support Manager

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Tap 0 is the port that captive portal uses for the url redirection. You can tcp dump directly off of that port to see what the traffic looks like....
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Doug Hyde, Technical Support Manager

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tcpdump -i tap0 -s 1600 -e -w capfile.cap

Then you can ftp the file off the controller for review... 
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Adilson Gal, Employee

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Thank you Doug for stepping in. I have been working with Luis Mendes on this case and we have an open case for the reported issue.