172.17.X.X subnet

SOLVED
tantony
Head in the Cloud

172.17.X.X subnet

My company acquired another company, and I was going to assign the new company 172.17.X.X/24 as the subnet.  Is there anything wrong with using 172.17.X.X because apparently this subnet cannot be routed?  

 

172.17.X.X is a valid private IP range.

 

172.16.0.0 to 172.31.255.255

1 ACCEPTED SOLUTION

Accepted Solutions
Inderdeep
Kind of a big deal

Re: 172.17.X.X subnet

@tantony : well i think i saw somewhere that All the IP addresses on our network start with 172.17 and have a 24-bit subnet mask is in the 'reserved' range of IP addresses that is not routable on the public Internet. That may cause issue.

Regards
Inderdeep Singh
www.thenetworkdna.com ( Awarded by Cisco IT Blogs award 2020)

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5 REPLIES 5
Inderdeep
Kind of a big deal

Re: 172.17.X.X subnet

@tantony : 172.17.X.X/24 subnet which give you valid User IPs ( 172.17.X.1 - 172.17.X.254). I dont think any issue with the IP range

Regards
Inderdeep Singh
www.thenetworkdna.com ( Awarded by Cisco IT Blogs award 2020)
tantony
Head in the Cloud

Re: 172.17.X.X subnet

@Inderdeep 

Thanks, that's what I thought also.  Yes, it should be fine.

The reason for my weird question is because, the previous IT guy told my co-worker something about not using 172.17.X.X on the company network.  We don't have any weird firewall rules to block this IP range.

Inderdeep
Kind of a big deal

Re: 172.17.X.X subnet

@tantony : well i think i saw somewhere that All the IP addresses on our network start with 172.17 and have a 24-bit subnet mask is in the 'reserved' range of IP addresses that is not routable on the public Internet. That may cause issue.

Regards
Inderdeep Singh
www.thenetworkdna.com ( Awarded by Cisco IT Blogs award 2020)

View solution in original post

tantony
Head in the Cloud

Re: 172.17.X.X subnet

https://www.arin.net/reference/research/statistics/address_filters/

 

May be this is the reason:

In August 2012, ARIN began allocating “172” address space to internet service, wireless, and content providers. There have been reports from the community that many network operators are denying access to devices having IP addresses from within the entire 172 /8 range. As a result, any device with a 172.x.x.x IP address may have difficulty reaching some sites on the global Internet. The only way to solve this problem is for those operators to reconfigure their routers or firewall access controls and filter only address space from the 172.16.0.0/12 range.

Inderdeep
Kind of a big deal

Re: 172.17.X.X subnet

@tantony : yes Correct !

Regards
Inderdeep Singh
www.thenetworkdna.com ( Awarded by Cisco IT Blogs award 2020)
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