AS for inter-AS link subnets?

Hi Lars, thanks for the response. It doesn't help much, but I expect it's because I left out the detail.

We use eBGP with private ASs. The subnets linking the ASs are not naturally part of any of the ASs and they are not currently announced. This has some niggling problems we'd like not to have. Consider a triangle of ASs, call them X, Y and Z. If the link between X and Y goes down then normal traffic between X and Y works just fine via Z, but the border routers in X and Y can't do simple debugging things to each other because they source traffic from the interfaces addresses of the X-Z and Y-Z links which aren't announced to Y and X respectively. Clearly you can specify the source addresses for the debugging commands to be, say, the loopback addresses of the routers, but you have to remember and it confuses people. :-)

So if we want to announce the inter-AS link subnets can we do it from both ASs or is there something else we should be doing?

Sam Wilson wrote in news:Sam.Wilson- snipped-for-privacy@scotsman.ed.ac.uk:

Hi Sam

You could choose not to announce the link at all, but normally the "owner" (the AS) who has the IP adresses assigned is the one to announce these IP adresses in the normal aggregation.

Hope this helps.

Regards, Lars

Assuming that the the interfaces connecting the AS's are advertised withing their respect IGP's, I do not see any reason for you to be able to annouce the "DMZ" links via EBGP.

If you have EBGP route filters these would need to be checked.

"... not to be able ..."?

Sam

yes, sorry for the typo