Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Announcements

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. If you'd prefer to explore, try our test area to get started. And see here for current known issues.

New Member

ip addressing for public router

hi guys,

Quick question about my addressing. Given the following:

internet<-->router<-->pix<-->core switch<-->lan

right now I have a public ip given to my by my isp on the outside int on the internet router as well as on the inside int of the same router, which connects to the outside int of the pix. whew...my question being, I am moving to a new isp and they have given me a block of ip's to use. in my current setup, the public ip on the outside of the internet router is from a different network than that of the inside facing the pix, i assume this is done by design to allow the interfaces to be on different subnets. with the new isp, i was not given this, only a block of ip addresses. should I be asking for one more public in a different subnet? or is there some way for me to use what i have?

TIA,

R

1 ACCEPTED SOLUTION

Accepted Solutions
Purple

Re: ip addressing for public router

Hi R,

How big is the block assigned to you by the new ISP ? Typically, the ISP will use a /30 for the link between them and your router and the address block you are assigned can then be assigned to the inside interface of your router.

Alsom, you can always subnet the IP block your ISP has assigned you in order to end up with distinct subnets on either side of your router.

Hope that helps - pls rate the post if it does.

Paresh

2 REPLIES
Purple

Re: ip addressing for public router

Hi R,

How big is the block assigned to you by the new ISP ? Typically, the ISP will use a /30 for the link between them and your router and the address block you are assigned can then be assigned to the inside interface of your router.

Alsom, you can always subnet the IP block your ISP has assigned you in order to end up with distinct subnets on either side of your router.

Hope that helps - pls rate the post if it does.

Paresh

New Member

Re: ip addressing for public router

my thoughts exactly...before you replied i called him and he said he thought he had already assigned me a /30...nice to know i was not totally off base!

thanks!

115
Views
0
Helpful
2
Replies