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ISP adds static route to internal addess

Hello Cisco, I'm trying to figure out why my ISP adds this static route to an internal address to my routing table. I was able to determine that it is very important by adding an ACL to block outbound traffic to it. Is it just some ISP magic?

Thank you in advance for any assistance!

!

interface FastEthernet4

ip address dhcp

ip nat outside

ip virtual-reassembly

speed 100

full-duplex

end

     70.0.0.0/24 is subnetted, 1 subnets

C       <omitted> is directly connected, FastEthernet4

     172.19.0.0/32 is subnetted, 1 subnets

S       172.19.41.19 [254/0] via 70.170.18.1, FastEthernet4

     192.168.0.0/29 is subnetted, 1 subnets

C       192.168.0.0 is directly connected, Loopback0

C    192.168.1.0/24 is directly connected, BVI1

S*   0.0.0.0/0 [254/0] via <omitted>

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ISP adds static route to internal addess

I am guessing that the address 172.19.41.19 is some kind of management or monitoring station in the provider network. I have seen some situations like this where the provider has management and/or monitoring stations that want to track the public address but the devices are in private address space within the provider network. I would suggest that you ask the provider about the address and about the impact if you block it. I have had the situation a couple of times where the customer did block the extra address and it did have a negative effect on their network connectivity.

HTH

Rick

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