Retaining IP Addresses When Changing Carriers

[HAYDON CHRISTOPHER]

I had a /28 with Global Crossing, now Level 3, that I assigned to my end users. I have since upgraded to a new Level 3 circuit but was told I cannot use my existing /28. They want to issue me a new Level 3 /28. This will create undue work. Is there any solution?

[Joseph W. Doherty · Accepted solution]

Disclaimer

The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.

Liability Disclaimer

In no event shall Author be liable for any damages whatsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.

Posting

Probably not, if you are changing ISPs.  Internet addressed blocks are assigned, and generally you cannot transfer subsets of address blocks.

If you had your own publicly assigned address block (and AS), that would stay with you, regardless of the ISP(s) you work with.

What you might consider is retaining the Global Crossing /28, for a while, allowing a slower migration to the Level 3 /28.

[mvsheik123 · Accepted solution]

 I second that. I did similar (parallel) cutover (with same ISP, new link) last year. Leaving the existing link and ip block and moved publicly assigned/advertised IPs at scheduled time. Waited for couple of days to make sure all works well and cancelled the other link.

hth

MS

[Richard Burts]

If you read carefully "I had a /28 with Global Crossing, now Level 3"  you would realize that Global Crossing was acquired by Level 3 and is now a part of Level 3. So in essence it is making changes within the same ISP.

See this link for some additional detail

http://en.wikipedia.org/wiki/Global_Crossing

HTH

Rick