[c-nsp] strange ARP issue, 40K worth of entries

[John Brown]

So I do a sh arp on a client router and it has 40K worth of entries.
The entries are public IP's all pointing upstream.

I've never seen anything like this.  Any thoughts ??  Mucho Thanks

Interface on service provider side.

interface Vlan8
 description v008.fttx.CUSTOMER
 ip address 216.XXX.YYY.249 255.255.255.252
 no ip redirects
end


Stuff on the Customer side.


r0ca#sh run int gi0/0.10
Building configuration...

Current configuration : 185 bytes
!
interface GigabitEthernet0/0.10
 description v010-outside-link
 encapsulation dot1Q 10
 ip address 216.XXX.YYY.250 255.255.255.252
 no ip unreachables
end


r0ca#sh arp sum
Total number of entries in the ARP table: 40750.
Total number of Dynamic ARP entries: 40729.
Total number of Incomplete ARP entries: 17.
Total number of Interface ARP entries: 4.
Total number of Static ARP entries: 0.
Total number of Alias ARP entries: 0.
Total number of Simple Application ARP entries: 0.
Total number of Application Alias ARP entries: 0.
Total number of Application Timer ARP entries: 0.

Interface              Entry Count
GigabitEthernet0/1.101          21
GigabitEthernet0/1.20           34
GigabitEthernet0/1.2             2
GigabitEthernet0/0.10        40693


Protocol  Address          Age (min)  Hardware Addr   Type   Interface
Internet  1.1.1.1                 4   00d0.02fc.d800  ARPA   GigabitEthernet0/0.10
Internet  1.22.17.130             5   00d0.02fc.d800  ARPA   GigabitEthernet0/0.10
Internet  1.22.72.41              5   00d0.02fc.d800  ARPA   GigabitEthernet0/0.10
Internet  1.22.233.14             5   00d0.02fc.d800  ARPA   GigabitEthernet0/0.10
Internet  1.23.6.132              4   00d0.02fc.d800  ARPA   GigabitEthernet0/0.10
Internet  1.23.15.138             4   00d0.02fc.d800  ARPA   GigabitEthernet0/0.10
Internet  1.23.88.51              4   00d0.02fc.d800  ARPA   GigabitEthernet0/0.10
Internet  1.23.158.76             4   00d0.02fc.d800  ARPA   GigabitEthernet0/0.10
Internet  1.23.168.27             4   00d0.02fc.d800  ARPA   GigabitEthernet0/0.10
Internet  1.23.168.186            5   00d0.02fc.d800  ARPA   GigabitEthernet0/0.10
Internet  1.23.172.153            4   00d0.02fc.d800  ARPA   GigabitEthernet0/0.10
Internet  1.23.176.35             4   00d0.02fc.d800  ARPA   GigabitEthernet0/0.10
Internet  1.23.199.245            5   00d0.02fc.d800  ARPA   GigabitEthernet0/0.10
Internet  1.36.21.104             4   00d0.02fc.d800  ARPA   GigabitEthernet0/0.10
Internet  1.38.157.234            4   00d0.02fc.d800  ARPA   GigabitEthernet0/0.10
Internet  1.38.187.174            4   00d0.02fc.d800  ARPA   GigabitEthernet0/0.10
Internet  1.40.190.118            4   00d0.02fc.d800  ARPA   GigabitEthernet0/0.10
Internet  1.40.217.64             4   00d0.02fc.d800  ARPA   GigabitEthernet0/0.10
Internet  1.44.87.158             4   00d0.02fc.d800  ARPA   GigabitEthernet0/0.10
Internet  1.53.8.24               4   00d0.02fc.d800  ARPA   GigabitEthernet0/0.10
Internet  1.53.95.222             4   00d0.02fc.d800  ARPA   GigabitEthernet0/0.10
Internet  1.53.166.6              4   00d0.02fc.d800  ARPA   GigabitEthernet0/0.10
Internet  1.54.23.243             4   00d0.02fc.d800  ARPA   GigabitEthernet0/0.10
Internet  1.55.61.97              4   00d0.02fc.d800  ARPA   GigabitEthernet0/0.10
Internet  1.55.92.139             4   00d0.02fc.d800  ARPA   GigabitEthernet0/0.10
Internet  1.55.168.151            4   00d0.02fc.d800  ARPA   GigabitEthernet0/0.10